Ken Zafren, MD FAAEM FACEP FAWM

All Publications

• End-tidal CO2 <10 mm Hg is not a reason to terminate cardiopulmonary resuscitation in hypothermic cardiac arrest. Resuscitation Zafren, K., Paal, P. 2022

  View details for DOI 10.1016/j.resuscitation.2022.03.007

  View details for PubMedID 35292303

• COVID-19 Lung Injury Is Different From High Altitude Pulmonary Edema (Re: High Alt Med Biol [Epub ahead of print]; DOI: 10.1089/ham.2020.0055). High altitude medicine & biology Brugger, H. n., Basnyat, B. n., Ellerton, J. n., Hefti, U. n., Strapazzon, G. n., Zafren, K. n. 2020

  View details for DOI 10.1089/ham.2020.0061

  View details for PubMedID 32364407

• The STAR Data Reporting Guidelines for Clinical High Altitude Research HIGH ALTITUDE MEDICINE & BIOLOGY Maeder, M., Brugger, H., Pun, M., Strapazzon, G., Dal Cappello, T., Maggiorini, M., Hackett, P., Baertsch, P., Swenson, E. R., Zafren, K., STAR Core Grp, STAR Delphi Expert Grp 2018; 19 (1): 7–14

  Abstract

  Brodmann Maeder, Monika, Hermann Brugger, Matiram Pun, Giacomo Strapazzon, Tomas Dal Cappello, Marco Maggiorini, Peter Hackett, Peter Baärtsch, Erik R. Swenson, Ken Zafren (STAR Core Group), and the STAR Delphi Expert Group. The STARdata reporting guidelines for clinical high altitude research. High AltMedBiol. 19:7-14, 2018.The goal of the STAR (STrengthening Altitude Research) initiative was to produce a uniform set of key elements for research and reporting in clinical high-altitude (HA) medicine. The STAR initiative was inspired by research on treatment of cardiac arrest, in which the establishment of the Utstein Style, a uniform data reporting protocol, substantially contributed to improving data reporting and subsequently the quality of scientific evidence.The STAR core group used the Delphi method, in which a group of experts reaches a consensus over multiple rounds using a formal method. We selected experts in the field of clinical HA medicine based on their scientific credentials and identified an initial set of parameters for evaluation by the experts.Of 51 experts in HA research who were identified initially, 21 experts completed both rounds. The experts identified 42 key parameters in 5 categories (setting, individual factors, acute mountain sickness and HA cerebral edema, HA pulmonary edema, and treatment) that were considered essential for research and reporting in clinical HA research. An additional 47 supplemental parameters were identified that should be reported depending on the nature of the research.The STAR initiative, using the Delphi method, identified a set of key parameters essential for research and reporting in clinical HA medicine.

  View details for PubMedID 29596018

  View details for PubMedCentralID PMC5905862

• High altitude illness in pilgrims after rapid ascent to 4380 M TRAVEL MEDICINE AND INFECTIOUS DISEASE Zafren, K., Pun, M., Regmi, N., Bashyal, G., Acharya, B., Gautam, S., Jamarkattel, S., Lamichhane, S. R., Acharya, S., Basnyat, B. 2017; 16: 31-34

  Abstract

  The goal of the study was to characterize high altitude illness in Nepali pilgrims.We kept standardized records at the Himalayan Rescue Association (HRA) Temporary Health Camp at Gosainkund Lake (4380 m) in the Nepal Himalaya during the annual Janai Purnima Festival in 2014. Records included rate of ascent and Lake Louise Score (LLS). We defined High Altitude Headache (HAH) as headache alone or LLS = 2. Acute Mountain Sickness (AMS) was LLS≥3. High Altitude Cerebral Edema (HACE) was AMS with ataxia or altered mental status.An estimated 10,000 pilgrims ascended rapidly, most in 1-2 days, from Dhunche (1960 m) to Gosainkund Lake (4380 m). We saw 769 patients, of whom 86 had HAH. There were 226 patients with AMS, including 11 patients with HACE. We treated patients with HACE using dexamethasone and supplemental oxygen prior to rapid descent. Each patient with HACE descended carried by a porter. There were no fatalities due to HACE. There were no cases of High Altitude Pulmonary Edema (HAPE).HAH and AMS were common in pilgrims ascending rapidly to 4380 m. There were 11 cases of HACE, treated with dexamethasone, supplemental oxygen and descent. There were no fatalities.

  View details for DOI 10.1016/j.tmaid.2017.03.002

  View details for PubMedID 28285976

• Delayed and intermittent CPR for severe accidental hypothermia RESUSCITATION Gordon, L., Paal, P., Ellerton, J. A., Brugger, H., Peek, G. J., Zafren, K. 2015; 90: 46-49

  Abstract

  Cardiac arrest (CA) in patients with severe accidental hypothermia (core temperature <28 °C) differs from CA in normothermic patients. Maintaining CPR throughout the prehospital period may be impossible, particularly during difficult evacuations. We have developed guidelines for rescuers who are evacuating and treating severely hypothermic CA patients.A literature search was performed. The authors used the findings to develop guidelines.Full neurological recovery is possible even with prolonged CA if the brain was already severely hypothermic before CA occurred. Data from surgery during deep hypothermic CA and prehospital case reports underline the feasibility of delayed and intermittent CPR in patients who have arrested due to severe hypothermia.Continuous CPR is recommended for CA due to primary severe hypothermia. Mechanical chest-compression devices should be used when available and CPR-interruptions avoided. Only if this is not possible should CPR be delayed or performed intermittently. Based on the available data, a patient with a core temperature <28 °C or unknown with unequivocal hypothermic CA, evidence supports alternating 5 min CPR and ≤5 min without CPR. With core temperature <20 °C, evidence supports alternating 5 min CPR and ≤10 min without CPR.

  View details for DOI 10.1016/j.resuscitation.2015.02.017

  View details for PubMedID 25725297

• Wilderness Medical Society practice guidelines for the out-of-hospital evaluation and treatment of accidental hypothermia: 2014 update. Wilderness & environmental medicine Zafren, K., Giesbrecht, G. G., Danzl, D. F., Brugger, H., Sagalyn, E. B., Walpoth, B., Weiss, E. A., Auerbach, P. S., McIntosh, S. E., Némethy, M., McDevitt, M., Dow, J., Schoene, R. B., Rodway, G. W., Hackett, P. H., Bennett, B. L., Grissom, C. K. 2014; 25 (4): S66-85

  Abstract

  To provide guidance to clinicians, the Wilderness Medical Society (WMS) convened an expert panel to develop evidence-based guidelines for the out-of-hospital evaluation and treatment of victims of accidental hypothermia. The guidelines present the main diagnostic and therapeutic modalities and provide recommendations for the management of hypothermic patients. The panel graded the recommendations based on the quality of supporting evidence and the balance between benefits and risks/burdens according the criteria published by the American College of Chest Physicians. The guidelines also provide suggested general approaches to the evaluation and treatment of accidental hypothermia that incorporate specific recommendations. This is an updated version of the original Wilderness Medical Society Practice Guidelines for the Out-of-Hospital Evaluation and Treatment of Accidental Hypothermia published in Wilderness & Environmental Medicine 2014;25(4):425-445.

  View details for DOI 10.1016/j.wem.2014.10.010

  View details for PubMedID 25498264

• Frostbite: Prevention and Initial Management HIGH ALTITUDE MEDICINE & BIOLOGY Zafren, K. 2013; 14 (1): 9-12

  Abstract

  Frostbite is a local freezing injury that can cause tissue loss. Historically, it has been a disease of wars, but it is a hazard for anyone who ventures outdoors in cold weather. Frozen tissue is damaged both during freezing and rewarming. Frozen tissue is numb. Rewarming causes hyperemia and is often painful. Blisters and edema develop after rewarming. Hard eschar may form with healthy tissue deep to the eschar. Frostbite can be classified as superficial, without permanent tissue loss, or deep, with varying degrees of permanent tissue loss, often less than appearances suggest. It can be difficult to predict the amount of tissue loss at the time of presentation and early in the subsequent course. Prevention is better than treatment. It may be advisable not to rewarm frozen extremities in the field, but spontaneous thawing is often unavoidable. Extremities that have thawed should be protected from refreezing at all costs. Once in a protected environment, extremities that are still frozen should be rapidly thawed in warm water. Therapy with aspirin or ibuprofen may be helpful, but evidence is limited. Thrombolytic treatment within the first 24 hours after rewarming seems to be beneficial in some cases of severe frostbite. Prostacyclin therapy is very promising.

  View details for DOI 10.1089/ham.2012.1114

  View details for PubMedID 23537254

• D-Dimer Is Not Elevated in Asymptomatic High Altitude Climbers after Descent to 5340 m: The Mount Everest Deep Venous Thrombosis Study (Ev-DVT) HIGH ALTITUDE MEDICINE & BIOLOGY Zafren, K., Feldman, J., Becker, R. J., Williams, S. R., Weiss, E. A., Deloughery, T. 2011; 12 (3): 223-227

  Abstract

  We performed this study to determine the prevalence of elevated D-dimer, a marker for deep venous thrombosis (DVT), in asymptomatic high altitude climbers. On-site personnel enrolled a convenience sample of climbers at Mt. Everest Base Camp (Nepal), elevation 5340 m (17,500 ft), during a single spring climbing season. Subjects were enrolled after descent to base camp from higher elevation. The subjects completed a questionnaire to evaluate their risk factors for DVT. We then performed a D-dimer test in asymptomatic individuals. If the D-dimer test was negative, DVT was considered ruled out. Ultrasound was available to perform lower-extremity compression ultrasounds to evaluate for DVT in case the D-dimer was positive. We enrolled 76 high altitude climbers. None had a positive D-dimer test. The absence of positive D-dimer tests suggests a low prevalence of DVT in asymptomatic high altitude climbers.

  View details for DOI 10.1089/ham.2010.1101

  View details for PubMedID 21962065

• Acetazolamide fails to decrease pulmonary artery pressure at high altitude in partially acclimatized humans HIGH ALTITUDE MEDICINE & BIOLOGY Basnyat, B., Hargrove, J., Holck, P. S., Srivastav, S., Alekh, K., Ghimire, L. V., Pandey, K., Griffiths, A., Shankar, R., Kaul, K., Paudyal, A., Stasiuk, D., Basnyat, R., Davis, C., Southard, A., Robinson, C., Shandley, T., Johnson, D. W., Zafren, K., Williams, S., Weiss, E. A., Farrar, J. J., Swenson, E. R. 2008; 9 (3): 209-216

  Abstract

  In this randomized, double-blind placebo controlled trial our objectives were to determine if acetazolamide is capable of preventing high altitude pulmonary edema (HAPE) in trekkers traveling between 4250 m (Pheriche)\4350 m (Dingboche) and 5000 m (Lobuje) in Nepal; to determine if acetazolamide decreases pulmonary artery systolic pressures (PASP) at high altitude; and to determine if there is an association with PASP and signs and symptoms of HAPE. Participants received either acetazolamide 250 mg PO BID or placebo at Pheriche\Dingboche and were reassessed in Lobuje. The Lake Louise Consensus Criteria were used for the diagnosis of HAPE, and cardiac ultrasonography was used to measure the velocity of tricuspid regurgitation and estimate PASP. Complete measurements were performed on 339 of the 364 subjects (164 in the placebo group, 175 in the acetazolamide group). No cases of HAPE were observed in either study group nor were differences in the signs and symptoms of HAPE found between the two groups. Mean PASP values did not differ significantly between the acetazolamide and placebo groups (31.3 and 32.6 mmHg, respectively). An increasing number of signs and symptoms of HAPE was associated with elevated PASP (p < 0.01). The efficacy of acetazolamide against acute mountain sickness, however, was significant with a 21.9% incidence in the placebo group compared to 10.2 % in the acetazolamide group (p < 0.01). Given the lack of cases of HAPE in either group, we can draw no conclusions about the efficacy of acetazolamide in preventing HAPE, but the absence of effect on PASP suggests that any effect may be minor possibly owing to partial acclimatization during the trek up to 4200 m.

  View details for DOI 10.1089/ham.2007.1073

  View details for Web of Science ID 000259759600004

  View details for PubMedID 18800957

• Lightning injuries: prevention and on-site treatment in mountains and remote areas - Official guidelines of the International Commission for Mountain Emergency Medicine and the Medical Commission of the International Mountaineering and Climbing Federation (ICAR and UIAA MEDCOM) RESUSCITATION Zafren, K., Durrer, B., Herry, J. P., Brugger, H. 2005; 65 (3): 369-372

  Abstract

  Lightning is a hazard during outdoor activities, especially for hikers and mountaineers. Specific preventive measures include staying off ridges and summits, and away from single trees. If possible, stay close to a wall but keeping a distance of at least 1m away from the wall. All metal objects (carabiners, crampons, ice-axe, ski poles, etc.) should be removed and stored away safely. Lightning currents can follow wet ropes. To prevent blunt trauma the helmet should not be removed. Move as quickly as possible away from wire ropes and iron ladders. The crouch position should be adopted immediately if there is a sensation of hair "standing on end". Crackling noises or a visible glow indicate an imminent lightning strike. Rescue of lightning victims may be hazardous. Airborne helicopters can be struck by lightning with disastrous effects. It is prudent to wait until the danger of further strikes has passed. Treatment of lightning victims is based upon the ABCs - (Assessment) airway, breathing and circulation. Victims who are not breathing can often be resuscitated and should be helped first. Respiratory arrest may be prolonged, but the prognosis can be excellent if breathing is supported. Standard Advanced Life Support (ALS), if necessary, should be given at the scene.

  View details for DOI 10.1016/j.resuscitation.2004.12.014

  View details for PubMedID 15919576

• Guidelines for the management of head injuries in remote and rural Alaska. Alaska medicine Sacco, F., Zafren, K., Brown, K., Cohen, T., COOPES, B. J., Godersky, J., Hudson, D., Hyams, S., Ingraham, D., Levy, M., Ma, W., Martinez, P., Montano, W., Mithun, J., O'Malley, J., O'Neill, K., Powers, D., Smith, L. 2004; 46 (3): 58-62

  Abstract

  Numerous recommendations on the initial evaluation and treatment of the head injured patient have been proposed over the last several years. Most assume there is readily available access to computed tomography and neurosurgical specialists. Many clinicians in Alaska must evaluate and begin treatment of head injured patients in circumstances quite different from this. Vast distances, severe weather and limited medical evacuation capability are factors that come into play while caring for these patients. The current medicolegal climate also contributes to clinician anxiety over missing rare but potentially serious injuries. These guidelines developed by Alaska clinicians from multiple specialties are meant to assist clinicians dealing with this very common problem and represent a reasonable approach to these patients in remote and rural Alaska.

  View details for PubMedID 15839596

• Thrombotic complications at altitude WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K. 2004; 15 (2): 155-155

  View details for Web of Science ID 000222041200015

  View details for PubMedID 15228070

• Trends in the workload of the two high altitude aid posts in the Nepal Himalayas JOURNAL OF TRAVEL MEDICINE Basnyat, B., Savard, G. K., Zafren, K. 1999; 6 (4): 217-222

  Abstract

  Acute mountain sickness (AMS), High altitude pulmonary edema (HAPE) and High Altitude Cerebral Edema (HACE) are well known problems in the high altitude region of the Nepal Himalayas. To assess the proportion of AMS, HAPE, and HACE from 1983 to 1995 in the Himalaya Rescue Association (HRA) aid posts' patients at the Everest (Pheriche 4,243 m) and Annapurna (Manang 3,499 m) regions, the two most popular trekking areas in the Himalayas. A retrospective study was conducted at the HRA medical aid posts in Manang (3,499 m) and Pheriche (4,243 m) in the Himalayas, where 4,655 trekkers (tourists, mostly Caucasians) and 4,792 Nepalis (mostly porters and villagers) were seen at the two high-altitude clinics from 1983 to 1995, for a variety of medical problems, including AMS.The number of trekking permits issued for entering the two most popular regions in the Himalayas was calculated and referenced to the proportion of trekkers with medical conditions. Well established guidelines like the Lake Louise Diagnostic Criteria were used in the assessment of AMS, HAPE and HACE. Linear regression analyses were performed on data collected from the two aid posts to determine the effect of time on each variable. For comparison between the aid posts, angular transformation (arcsine) and analysis of variance (ANOVA) were performed on all proportional (incidence) data.Approximately 20% of all visitors (Nepali plus trekkers) who visited the higher Pheriche aid post were diagnosed with AMS compared to around 6% at the lower Manang aid post. There was a linear increase over time in the number of trekkers entering the Everest (r=0.904, p<.001) and the Annapurna (r=0.887, p<.001) regions. The proportion of trekker patients with any medical condition visiting the two HRA aid posts at Manang and Pheriche, expressed as a function of the total number of trekkers entering the Everest and Annapurna regions, was not significantly different between Pheriche (average 4%) and Manang (average 1%). However, the proportion of AMS, HAPE and HACE in patients (Nepali plus trekkers) to the aid posts was greater in those visiting the higher Pheriche aid post compared to the lower Manang aid post (f=56.74, n=13; p<. 001). Importantly, only the proportion of AMS (r=0.568; p<.05) and not HAPE or HACE increased over time in Pheriche, alongside an unchanged proportion of trekker patients, amongst all Pheriche aid post patients. There was no increase of AMS, HAPE or HACE in Manang.HAPE and HACE are the life-threatening forms of AMS and although there is a linear increase of trekkers entering the Himalayas in Nepal, the findings revealed that HAPE and HACE have not increased over time. One possible explanation may be that awareness drives by organizations like the Himalayan Rescue Association may be effective in preventing the severe forms of AMS.

  View details for Web of Science ID 000084359600001

  View details for PubMedID 10575168

• Images - Chilblains (pernio) WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K. 1999; 10 (1): 25-26

  View details for Web of Science ID 000079896900007

  View details for PubMedID 10347676

• Gamow bag for high-altitude cerebral oedema LANCET Zafren, K. 1998; 352 (9124): 325-326

  View details for Web of Science ID 000074974500065

  View details for PubMedID 9690443

• Hyponatremia in a cold environment WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K. 1998; 9 (1): 54-55

  View details for Web of Science ID 000080104600010

  View details for PubMedID 11990182

• High-altitude medicine. Emergency medicine clinics of North America Zafren, K., Honigman, B. 1997; 15 (1): 191-222

  Abstract

  This article discusses prevention, recognition, and treatment of altitude illnesses, especially acute mountain sickness, high-altitude pulmonary edema, and high-altitude cerebral edema. Physicians advising travelers and trekkers who will be visiting high-altitude areas will find an organized approach to giving pretravel advice. Physicians practicing in or visiting high-altitude areas will find guidelines for diagnosis and treatment. This article also addresses the issue of patients with underlying diseases who wish to travel to high-altitude destinations.

  View details for PubMedID 9056576

• Treatment of high-altitude pulmonary edema by bed rest and supplemental oxygen WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K., Reeves, J. T., Schoene, R. 1996; 7 (2): 127-132

  Abstract

  We evaluated the safety and efficacy of treating high-altitude pulmonary edema (HAPE) by bed rest and supplemental oxygen at moderate altitudes. We also characterized clinical parameters in HAPE before and after treatment.Case series.Two primary care centers at about 9,200 feet (2,800 meters) above sea level.All patients aged 16-69 years who had been diagnosed with HAPE and were treated with bed rest and supplemental oxygen. Patients were seen on a follow-up visit. Interventions: Selected patients were treated with bed rest and supplemental oxygen rather than hospital admission or descent.Patients were considered improved on follow-up if room air arterial oxygen saturation was increased by 10 percentage points or if their symptoms had improved.Of 58 patients with confirmed HAPE, 25 (43%) were treated by bed rest and supplemental oxygen and were seen on return visits to the clinic. All of the treated patients improved at the return visit. Systolic blood pressure, heart rate, respiratory rate, and temperature decreased significantly between the first visit and the return visit. Oxygen saturation improved between visits.Some patients with HAPE at moderate altitudes where medical facilities are available can be safely treated with bed rest and oxygen without descent.

  View details for Web of Science ID A1996XU76000004

  View details for PubMedID 11990106

• SEASONAL-VARIATION IN BAROMETRIC-PRESSURE AND TEMPERATURE IN SUMMIT-COUNTY - EFFECT ON ALTITUDE ILLNESS 8th International Hypoxia Symposium Reeves, J. T., Wagner, J., Zafren, K., Honigman, B., SCHOENE, R. B. CHARLES S HOUSTON. 1993: 275–281

  View details for Web of Science ID A1993BZ66T00027

• MORE ON TETRACYCLINE AND TICKS NEW ENGLAND JOURNAL OF MEDICINE Zafren, K. 1983; 308 (7): 403-404

  View details for Web of Science ID A1983QB71800029

  View details for PubMedID 6823249

• In Reply to Drs. Rousson, Hall, and Pasquier. Wilderness & environmental medicine Van Tilburg, C., Paal, P., Strapazzon, G., Grissom, C. K., Haegeli, P., Hölzl, N., McIntosh, S., Radwin, M., Smith, W. W., Thomas, S., Tremper, B., Weber, D., Wheeler, A. R., Zafren, K., Brugger, H. 2024: 10806032241245617

  View details for DOI 10.1177/10806032241245617

  View details for PubMedID 38629489

• Women at Altitude: Menstrual-Cycle Phase, Menopause, and Exogenous Progesterone Are Not Associated with Acute Mountain Sickness. High altitude medicine & biology Gardner, L., Keyes, L. E., Phillips, C., Small, E., Adhikari, T., Barott, N., Zafren, K., Maharjan, R., Marvel, J. 2024

  Abstract

  Gardner, Laurel, Linda E. Keyes, Caleb Phillips, Elan Small, Tejaswi Adhikari, Nathan Barott, Ken Zafren, Rony Maharjan, and James Marvel. Women at altitude: Menstrual-cycle phase, menopause, and exogenous progesterone are not associated with acute mountain sickness. High Alt Med Biol. 00:000-000, 2024. Background: Elevated progesterone levels in women may protect against acute mountain sickness (AMS). The impact of hormonal contraception (HC) on AMS is unknown. We examined the effect of natural and exogenous progesterone on the occurrence of AMS. Methods: We conducted a prospective observational convenience study of female trekkers in Lobuche (4,940 m) and Manang (3,519 m). We collected data on last menstrual period, use of exogenous hormones, and development of AMS. Results: There were 1,161 trekkers who met inclusion criteria, of whom 307 (26%) had AMS. There was no significant difference in occurrence of AMS between women in the follicular (28%) and the luteal (25%) phases of menstruation (p = 0.48). The proportion of premenopausal (25%) versus postmenopausal women (30%) with AMS did not differ (p = 0.33). The use of HC did not influence the occurrence of AMS (HC 23% vs. no HC 26%, p = 0.47), nor did hormonal replacement therapy (HRT) (HRT 11% vs. no HRT 31%, p = 0.13). Conclusion: We found no relationship between menstrual-cycle phase, menopausal status, or use of exogenous progesterone and the occurrence of AMS in trekkers and conclude that hormonal status is not a risk factor for AMS. Furthermore, women should not be excluded from future AMS studies based on hormonal status.

  View details for DOI 10.1089/ham.2023.0100

  View details for PubMedID 38516987

• About Rewarming Young Children After Drowning-Associated Hypothermia and Out-of-Hospital Cardiac Arrest. Pediatric critical care medicine : a journal of the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies Cools, E., Brugger, H., Darocha, T., Gordon, L., Pasquier, M., Walpoth, B., Zafren, K., Peek, G., Paal, P. 2024; 25 (3): e171-e172

  View details for DOI 10.1097/PCC.0000000000003411

  View details for PubMedID 38451805

  View details for PubMedCentralID PMC10903992

• Frostbite treatment: a systematic review with meta-analyses. Scandinavian journal of trauma, resuscitation and emergency medicine Regli, I. B., Oberhammer, R., Zafren, K., Brugger, H., Strapazzon, G. 2023; 31 (1): 96

  Abstract

  Our objective was to perform a systematic review of the outcomes of various frostbite treatments to determine which treatments are effective. We also planned to perform meta-analyses of the outcomes of individual treatments for which suitable data were available.We performed a systematic review and meta-analyses in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. We searched PubMed, Cochrane Trials, and EMBase to identify primary references from January 1, 1900, to June 18, 2022. After eliminating duplicates, we screened abstracts to identify eligible studies containing information on treatment and outcomes of Grade 2 to 4 frostbite. We performed meta-analyses of groups of articles that provided sufficient data. We registered our review in the prospective registry of systematic reviews PROSPERO (Nr. 293,693). We identified 4,835 potentially relevant studies. We excluded 4,610 studies after abstract screening. We evaluated the full text of the remaining 225 studies, excluding 154. Ultimately, we included 71 articles with 978 cases of frostbite originating from 1 randomized controlled trial, 20 cohort studies and 51 case reports. We found wide variations in classifications of treatments and outcomes. The two meta-analyses we performed both found that patients treated with thrombolytics within 24 h had better outcomes than patients treated with other modalities. The one randomized controlled trial found that the prostacyclin analog iloprost was beneficial in severe frostbite if administered within 48 h.Iloprost and thrombolysis may be beneficial for treating frostbite. The effectiveness of other commonly used treatments has not been validated. More prospective data from clinical trials or an international registry may help to inform optimal treatment.

  View details for DOI 10.1186/s13049-023-01160-3

  View details for PubMedID 38072923

  View details for PubMedCentralID PMC10712146

• Wilderness Medical Society Clinical Practice Guidelines for Prevention and Management of Avalanche and Nonavalanche Snow Burial Accidents: 2024 Update. Wilderness & environmental medicine Van Tilburg, C., Paal, P., Strapazzon, G., Grissom, C. K., Haegeli, P., Hölzl, N., McIntosh, S., Radwin, M., Smith, W. W., Thomas, S., Tremper, B., Weber, D., Wheeler, A. R., Zafren, K., Brugger, H. 2023

  Abstract

  To provide guidance to the general public, clinicians, and avalanche professionals about best practices, the Wilderness Medical Society convened an expert panel to revise the evidence-based guidelines for the prevention, rescue, and resuscitation of avalanche and nonavalanche snow burial victims. The original panel authored the Wilderness Medical Society Practice Guidelines for Prevention and Management of Avalanche and Nonavalanche Snow Burial Accidents in 2017. A second panel was convened to update these guidelines and make recommendations based on quality of supporting evidence.

  View details for DOI 10.1016/j.wem.2023.05.014

  View details for PubMedID 37945433

• Wilderness Medical Society Clinical Practice Guidelines for the Prevention, Diagnosis, and Treatment of Acute Altitude Illness: 2024 Update. Wilderness & environmental medicine Luks, A. M., Beidleman, B. A., Freer, L., Grissom, C. K., Keyes, L. E., McIntosh, S. E., Rodway, G. W., Schoene, R. B., Zafren, K., Hackett, P. H. 2023

  Abstract

  To provide guidance to clinicians about best practices, the Wilderness Medical Society (WMS) convened an expert panel to develop evidence-based guidelines for prevention, diagnosis, and treatment of acute mountain sickness, high altitude cerebral edema, and high altitude pulmonary edema. Recommendations are graded based on the quality of supporting evidence and the balance between the benefits and risks/burdens according to criteria put forth by the American College of Chest Physicians. The guidelines also provide suggested approaches for managing each form of acute altitude illness that incorporate these recommendations as well as recommendations on how to approach high altitude travel following COVID-19 infection. This is an updated version of the original WMS Consensus Guidelines for the Prevention and Treatment of Acute Altitude Illness published in Wilderness & Environmental Medicine in 2010 and the subsequently updated WMS Practice Guidelines for the Prevention and Treatment of Acute Altitude Illness published in 2014 and 2019.

  View details for DOI 10.1016/j.wem.2023.05.013

  View details for PubMedID 37833187

• Physiological Effects of Sildenafil Versus Placebo at High Altitude: A Systematic Review. High altitude medicine & biology Poudel, S., Gautam, S., Adhikari, P., Zafren, K. 2023

  Abstract

  Poudel, Sangeeta, Sandesh Gautam, Purushottam Adhikari, and Ken Zafren. Physiological effects of sildenafil versus placebo at high altitude: a systematic review. High Alt Med Biol. 00:000-000, 2023. Introduction: High altitude pulmonary edema (HAPE), a life-threatening condition that affects individuals ascending to high altitude, requires the development of pulmonary hypertension. Sildenafil can be used to prevent and treat HAPE, presumably by decreasing pulmonary artery pressure (PaP). We compared the physiological effects of sildenafil versus placebo at high altitude (above 2,500m), including the effects on PaP. Methods: We performed a systematic search of PubMed, EMBASE, and Cochrane CENTRAL for randomized controlled studies of the physiological effects of sildenafil in hypoxia in healthy individuals. We conducted a systematic review of all studies meeting our criteria. Results: Of the 14 studies that met the inclusion criteria, 8 were hypobaric hypoxia studies. Six studies reported data at rest at altitudes from 3,650 to 5,245m. Two were simulations reporting exercise data at equivalent altitudes of 2,750-5,000m. Nine studies used normobaric hypoxia corresponding to altitudes between 2,500 and 6,400m. One reported only rest data, two reported rest and exercise data, and the others reported only exercise data. Sildenafil significantly reduced PaP at rest and exercise in hypobaric or normobaric hypoxia. There were no significant differences between arterial oxygen saturation (SpO2) with sildenafil in hypobaric or normobaric hypoxia at rest or exercise. There were no significant differences in heart rate or mean arterial pressure (MAP) at rest or exercise and cardiac output during exercise in hypobaric or normobaric hypoxia. Conclusions: Sildenafil significantly reduces PaP at rest and exercise in normobaric or hypobaric hypoxia. Sildenafil has no significant effects on SpO2, heart rate, cardiac output (during exercise), or MAP at rest or exercise in hypobaric or normobaric hypoxia.

  View details for DOI 10.1089/ham.2022.0043

  View details for PubMedID 37751174

• Termination of Cardiopulmonary Resuscitation in Mountain Rescue: A Scoping Review and ICAR MedCom 2023 Recommendations. High altitude medicine & biology Lugnet, V., McDonough, M., Gordon, L., Galindez, M., Mena Reyes, N., Sheets, A., Zafren, K., Paal, P. 2023

  Abstract

  Lugnet, Viktor, Miles McDonough, Les Gordon, Mercedes Galindez, Nicolas Mena Reyes, Alison Sheets, Ken Zafren, and Peter Paal. Termination of cardiopulmonary resuscitation in mountain rescue: a scoping review and ICAR MedCom 2023 recommendations. High Alt Med Biol 00:000-000, 2023. Background: In 2012, the International Commission for Mountain Emergency Medicine (ICAR MedCom) published recommendations for termination of cardiopulmonary resuscitation (CPR) in mountain rescue. New developments have necessitated an update. This is the 2023 update for termination of CPR in mountain rescue. Methods: For this scoping review, we searched the PubMed and Cochrane libraries, updated the recommendations, and obtained consensus approval within the writing group and the ICAR MedCom. Results: We screened a total of 9,102 articles, of which 120 articles met the inclusion criteria. We developed 17 recommendations graded according to the strength of recommendation and level of evidence. Conclusions: Most of the recommendations from 2012 are still valid. We made minor changes regarding the safety of rescuers and responses to primary or traumatic cardiac arrest. The criteria for termination of CPR remain unchanged. The principal changes include updated recommendations for mechanical chest compression, point of care ultrasound (POCUS), extracorporeal life support (ECLS) for hypothermia, the effects of water temperature in drowning, and the use of burial times in avalanche rescue.

  View details for DOI 10.1089/ham.2023.0068

  View details for PubMedID 37733297

• History of Avalanches in the Eastern Spanish Pyrenees. Wilderness & environmental medicine Blasco Mariño, R., Martínez, I. S., Bacardit, M., Zafren, K., Paal, P. 2023

  View details for DOI 10.1016/j.wem.2023.07.008

  View details for PubMedID 37696722

• Isolated high altitude psychosis, delirium at high altitude, and high altitude cerebral edema: are these diagnoses valid? Frontiers in psychiatry Hüfner, K., Falla, M., Brugger, H., Gatterer, H., Strapazzon, G., Tomazin, I., Zafren, K., Sperner-Unterweger, B., Fusar-Poli, P. 2023; 14: 1221047

  Abstract

  Psychosis is a psychopathological syndrome that can be triggered or caused by exposure to high altitude (HA). Psychosis can occur alone as isolated HA psychosis or can be associated with other mental and often also somatic symptoms as a feature of delirium. Psychosis can also occur as a symptom of high altitude cerebral edema (HACE), a life-threatening condition. It is unclear how psychotic symptoms at HA should be classified into existing diagnostic categories of the most widely used classification systems of mental disorders, including the Diagnostic and Statistical Manual of Mental Disorders (DSM-V) and the International Statistical Classification of Diseases and Related Health Problems (ICD-11). We provide a diagnostic framework for classifying symptoms using the existing diagnostic categories: psychotic condition due to a general medical condition, brief psychotic disorder, delirium, and HACE. We also discuss the potential classification of isolated HA psychosis into those categories. A valid and reproducible classification of symptoms is essential for communication among professionals, ensuring that patients receive optimal treatment, planning further trips to HA for individuals who have experienced psychosis at HA, and advancing research in the field.

  View details for DOI 10.3389/fpsyt.2023.1221047

  View details for PubMedID 37599873

  View details for PubMedCentralID PMC10436335

• A unique cause of severe chest pain in the emergency department. Journal of the American College of Emergency Physicians open Starrs, M., Zafren, K. 2023; 4 (3): e12982

  View details for DOI 10.1002/emp2.12982

  View details for PubMedID 37260539

  View details for PubMedCentralID PMC10227360

• Takotsubo Cardiomyopathy Following Complete Avalanche Burial: A Case Report. High altitude medicine & biology Libersa, M., Marxer, L., Zafren, K., Oggier, S., Pucci, L., Pasquier, M. 2023

  Abstract

  Libersa, Marie, Louis Marxer, Ken Zafren, Stephane Oggier, Lorenzo Pucci, and Mathieu Pasquier. Takotsubo cardiomyopathy following complete avalanche burial: a case report. High Alt Med Biol. 22:000-000, 2023.-Takotsubo cardiomyopathy is a transient left ventricular dyskinesia triggered by a stressful physical or emotional event. We report a case of mid-ventricular Takotsubo stress cardiomyopathy in an avalanche victim. The patient was a 41-year-old woman who was completely buried under 1.2m of snow for 30 minutes. On arrival at the hospital, she was conscious and hypothermic (core temperature 33.7°C). Her ECG showed rapid atrial fibrillation (142 beats/min) that converted to sinus rhythm after rewarming and administration of crystalloids. Echocardiography showed akinesia of the left mid-ventricle with a left ventricular ejection fraction of 41%. At 48-hour follow-up, echocardiography showed an almost complete recovery. During her hospital stay the patient was diagnosed with an acute stress disorder with symptoms of dissociation. She was discharged home after 5 days. At 2-week follow-up echocardiography was normal. Psychological follow-up was normal at 7 months. The physical and psychological stress of the avalanche, as well as hypothermia, were all possible triggers of Takotsubo cardiomyopathy.

  View details for DOI 10.1089/ham.2023.0026

  View details for PubMedID 37262197

• Prevention and Treatment of Nonfreezing Cold Injuries and Warm Water Immersion Tissue Injuries: Supplement to Wilderness Medical Society Clinical Practice Guidelines for the Prevention and Treatment of Frostbite. Wilderness & environmental medicine Zafren, K., Hollis, S., Weiss, E. A., Danzl, D., Wilburn, J., Kimmel, N., Imray, C., Giesbrecht, G., Tipton, M. 2023

  Abstract

  We convened an expert panel to develop evidence-based guidelines for the evaluation, treatment, and prevention of nonfreezing cold injuries (NFCIs; trench foot and immersion foot) and warm water immersion injuries (warm water immersion foot and tropical immersion foot) in prehospital and hospital settings. The panel graded the recommendations based on the quality of supporting evidence and the balance between benefits and risks/burdens according to the criteria published by the American College of Chest Physicians. Treatment is more difficult with NFCIs than with warm water immersion injuries. In contrast to warm water immersion injuries that usually resolve without sequelae, NFCIs may cause prolonged debilitating symptoms, including neuropathic pain and cold sensitivity.

  View details for DOI 10.1016/j.wem.2023.02.006

  View details for PubMedID 37130771

• Letter: Is Altitude-Induced Sleep Apnea Highly Dependent on Ethnic Background (Sherpa vs. Tamang)? We Are Not Convinced. High altitude medicine & biology Zafren, K., Pun, M., Basnyat, B. 2023

  View details for DOI 10.1089/ham.2022.0138

  View details for PubMedID 36607790

• Survival in a Collapsed Stable for 37 Days After Avalanche Burial in 1755. Wilderness & environmental medicine Lechner, R., Brugger, H., Paal, P., Hüfner, K., Agazzi, G., Butler, F., Gordon, L., Darocha, T., Zafren, K. 2022

  Abstract

  In 1755 in Bergemoletto, Italy, an avalanche buried 4 people (2 women, a girl, and a boy) and several animals in a stable. After 37 d in a pitch-dark confined space, 3 of the 4 people were rescued alive. The 3 survivors had only goat milk, a few chestnuts, a few kg of raw kid meat, and meltwater for nutrition. We describe the longest-known survival in an avalanche burial and discuss the medical and psychological problems of the survivors. The boy died. When they were extricated, all 3 survivors were exhausted, cachectic, and unable to stand or walk. They were severely malnourished and were experiencing tingling, tremors, and weakness in the legs; constipation; changes in taste; and amenorrhea. One of the women had persistent eye problems and developed symptoms consistent with post-traumatic stress disorder. The survivors were given slow refeeding. It took from 1 to 6 wk before they could walk. We compare this case to other long-duration burials, especially mining accidents, and describe the rescue and patient care after long-duration burials. This case demonstrates that people can overcome extremely adverse conditions and survive.

  View details for DOI 10.1016/j.wem.2022.10.008

  View details for PubMedID 36526516

• Strengthening Altitude Knowledge: A Delphi Study to Define Minimum Knowledge of Altitude Illness for Laypersons Traveling to High Altitude. High altitude medicine & biology Berendsen, R. R., Bartsch, P., Basnyat, B., Berger, M. M., Hackett, P., Luks, A. M., Richalet, J., Zafren, K., Kayser, B., STAK Plenary Group, Anholm, J., Auerbach, P. S., Beidleman, B. A., Bloch, K. E., Brodmann, M., Brugger, H., Burtscher, M., Dehnert, C., Dumont, L., Faulhaber, M., Fischer, R., Gatterer, H., Gekeler, F., Grissom, C. K., Grocott, M. P., Hillebrandt, D., Honigman, B., Imray, C., Koehle, M. S., Lipman, G. S., Loeppky, J. A., Maggiorini, M., Moore, L. G., Muza, S. R., Pun, M., Roach, R. C., Sartori, C., Scherrer, U., Sikri, G., Subudhi, A. W., Swenson, E. R., Thompson, A. A., Verges, S., Woods, D. R. 2022

  Abstract

  Berendsen, Remco R., Peter Bartsch, Buddha Basnyat, Marc Moritz Berger, Peter Hackett, Andrew M. Luks, Jean-Paul Richalet, Ken Zafren, Bengt Kayser, and the STAK Plenary Group. Strengthening altitude knowledge: a Delphi study to define minimum knowledge of altitude illness for laypersons traveling to high altitude. High Alt Med Biol. 00:000-000, 2022. Introduction: A lack of knowledge among laypersons about the hazards of high-altitude exposure contributes to morbidity and mortality from acute mountain sickness (AMS), high-altitude cerebral edema (HACE), and high-altitude pulmonary edema (HAPE) among high-altitude travelers. There are guidelines regarding the recognition, prevention, and treatment of acute-altitude illness for experts, but essential knowledge for laypersons traveling to high altitudes has not been defined. We sought expert consensus on the essential knowledge required for people planning to travel to high altitudes. Methods: The Delphi method was used. The panel consisted of two moderators, a core expert group and a plenary expert group. The moderators made a preliminary list of statements defining the desired minimum knowledge for laypersons traveling to high altitudes, based on the relevant literature. These preliminary statements were then reviewed, supplemented, and modified by a core expert group. A list of 33 statements was then presented to a plenary group of experts in successive rounds. Results: It took three rounds to reach a consensus. Of the 10 core experts invited, 7 completed all the rounds. Of the 76 plenary experts, 41 (54%) participated in Round 1, and of these 41 a total of 32 (78%) experts completed all three rounds. The final list contained 28 statements in 5 categories (altitude physiology, sleeping at altitude, AMS, HACE, and HAPE). This list represents an expert consensus on the desired minimum knowledge for laypersons planning high-altitude travel. Conclusion: Using the Delphi method, the STrengthening Altitude Knowledge initiative yielded a set of 28 statements representing essential learning objectives for laypersons who plan to travel to high altitudes. This list could be used to develop educational interventions.

  View details for DOI 10.1089/ham.2022.0083

  View details for PubMedID 36201281

• Survival After Being Wedged in a Crevasse for 16 Hours in Alaska. Wilderness & environmental medicine Giesbrecht, G. G., Zafren, K., Anderson, J., Erickson, C. 2022

  Abstract

  We present a case of an un-roped mountaineer who fell into a crevasse during descent from the summit of Denali (Mount McKinley). He was wedged about 20 m deep in the crevasse for a total of 16 h; this included 4.5 h waiting for a rescue team to arrive, and an 11.5 h extrication process. His condition deteriorated and he eventually lost consciousness. Even though the rescue team collectively felt there was little or no chance of survival, they continued until the victim was extricated from the crevasse. He was almost immediately placed in a hypothermia wrap with active warming, loaded on a rescue helicopter, and transported for 1 h 40 min to a hospital in Fairbanks, Alaska. During the flight, he was placed on supplemental oxygen. He was cold to the touch; respiration was detectable, but a pulse was not, and he was responsive to verbal stimuli. Initial bladder temperature in hospital was 26.1°C. He was released from hospital after 14 d and made a full recovery. This case highlights an important mix of preventative and resuscitative lessons regarding crevasse rescue in an isolated location. The lessons include the dangers of travelling un-roped on a crevassed glacier, the challenges of extrication from a confined space, the fact that respirations are often more easily detected than pulses, an extended transport time to medical facilities, and the necessity of trying unorthodox extrication methods. This case emphasized the need to continue extrication and treatment efforts for a cold patient even when survival with hypothermia seems impossible.

  View details for DOI 10.1016/j.wem.2022.07.005

  View details for PubMedID 36089495

• Association of Pre-existing Mental Health Conditions with Acute Mountain Sickness at Everest Base Camp. High altitude medicine & biology Hufner, K., Caramazza, F., Pircher Nockler, E. R., Stawinoga, A. E., Fusar-Poli, P., Bhandari, S. S., Basnyat, B., Brodmann Maeder, M., Strapazzon, G., Tomazin, I., Zafren, K., Brugger, H., Sperner-Unterweger, B. 2022

  Abstract

  Hufner, Katharina, Fabio Caramazza, Evelyn R. Pircher Nockler, Agnieszka E. Stawinoga, Paolo Fusar-Poli, Sanjeeb S. Bhandari, Buddha Basnyat, Monika Brodmann Maeder, Giacomo Strapazzon, Iztok Tomazin, Ken Zafren, Hermann Brugger, and Barbara Sperner-Unterweger. Association of pre-existing mental health conditions with acute mountain sickness at Everest Base Camp. High Alt Med Biol. xx:xxx-xxx, 2022. Background: Mental health disorders are common, but limited data are available regarding the number of people with a past medical history of psychiatric diagnoses going to high altitude (HA). It is also unknown whether mental health conditions are associated with an increased risk of acute mountain sickness (AMS). Methods: We analyzed data from a previous study at Everest Base Camp. Participants self-reported their past medical history and history of substance use and had a brief history taken by a physician. AMS was assessed using the self-reported 2018 Lake Louise AMS Score. Results: Eighty-five participants (66 men and 19 women, age 38±9 years) were included. When questioned by a physician, 28 participants reported prior diagnoses or symptoms compatible with depression (23%), anxiety disorder (6%), post-traumatic stress disorder (1%), and psychosis/psychotic experiences (9%). The prevalence of psychiatric diagnoses in the past medical history was much lower in the self-reported data (2/85) compared to data obtained via physician assessment (28/85). Increased risks of AMS were associated with a past medical history of anxiety disorder (odds ratio [OR] 22.7; confidence interval [95% CI] 2.3-220.6; p<0.001), depression (OR 3.6; 95% CI 1.2-11.2; p=0.022), and recreational drug use ever (OR 7.3; 95% CI 1.5-35.5; p=0.006). Conclusions: Many people who travel to HA have a past medical history of mental health conditions. These individuals have an increased risk of scoring positive for AMS on the Lake Louise Score compared with people without a history of mental health conditions.

  View details for DOI 10.1089/ham.2022.0014

  View details for PubMedID 36070557

• Advising travellers beyond infectious diseases: can we learn from our forebears? Journal of travel medicine Kupper, T., Zafren, K., Visser, J. 2022

  View details for DOI 10.1093/jtm/taac091

  View details for PubMedID 35899876

• Isolated Ptosis Following a Vipera aspis Bite. Wilderness & environmental medicine Blasco Marino, R., Soteras Martinez, I., Hernandez Roca, A. I., Zafren, K. 2022

  Abstract

  In Spain, snakebites are uncommon medical emergencies that cause barely 100 hospitalizations annually. Most of the venomous bites are by snakes of the Viperidae family. Venom from Vipera snakes is reported to have cytotoxic and hematotoxic effects, and neurological effects have also been described. Ptosis (cranial nerve III palsy) is the most common sign, although any cranial nerve can be affected. We describe isolated ptosis, which was very likely after a Vipera aspis bite in the East Catalonian Pyrenees. No antivenom was administered. The ptosis resolved spontaneously within 10 h. Although neurologic findings are usually mild, they indicate a moderate or severe envenomation. Treating snakebites can be challenging for clinicians, especially when there are uncommon clinical manifestations. A toxicologist at a poison center should be consulted to help guide management. Development of local protocols may provide clinical support.

  View details for DOI 10.1016/j.wem.2022.02.007

  View details for PubMedID 35367125

• Prehospital Use of Ultrathin Reflective Foils WILDERNESS & ENVIRONMENTAL MEDICINE Kosinski, S., Podsiadlo, P., Darocha, T., Pasquier, M., Mendrala, K., Sanak, T., Zafren, K. 2022; 33 (1): 134-139

  View details for Web of Science ID 000766310000019

• Induced Hypothermia to as Cold as 3°C in Humans: Forgotten Cases Rediscovered. High altitude medicine & biology Zafren, K., Lechner, R., Paal, P., Brugger, H., Peek, G., Darocha, T. 1800

  Abstract

  Zafren, Ken, Raimund Lechner, Peter Paal, Hermann Brugger, Giles Peek, and Tomasz Darocha. Induced hypothermia to as cold as 3°C in humans: Forgotten cases rediscovered. High Alt Med Biol. 22:000-000, 2021. The lowest temperature from which humans can be successfully rewarmed from accidental hypothermia is unknown. The lowest published core temperature with survival from accidental hypothermia is 11.8°C. We recently reported a rediscovered case series of patients in whom profound hypothermia was induced for surgery. The patient in this case series with the lowest core temperature, 4.2°C, survived neurologically intact. We subsequently rediscovered several additional case series of induced hypothermia to core temperatures below 11.8°C. In one case series, at least one patient was cooled to 3°C. We do not know if any patient survived cooling to 3°C. As in the previous case series, the authors of the additional reports presented physiological data at various core temperatures, showing wide variations in individual responses to hypothermia. These data add to our understanding of the physiology of profound hypothermia. Although induced hypothermia for surgery differs from accidental hypothermia, survival from very low temperatures in induced hypothermia provides evidence that humans with accidental hypothermia can be resuscitated successfully from temperatures much lower than 11.8°C. We continue to advise against using core temperature alone to decide if a hypothermic patient in cardiac arrest has a chance of survival.

  View details for DOI 10.1089/ham.2021.0144

  View details for PubMedID 35099289

• Prevention of Hypothermia in the Aftermath of Natural Disasters in Areas at Risk of Avalanches, Earthquakes, Tsunamis and Floods. International journal of environmental research and public health Oshiro, K., Tanioka, Y., Schweizer, J., Zafren, K., Brugger, H., Paal, P. 2022; 19 (3)

  Abstract

  Throughout history, accidental hypothermia has accompanied natural disasters in cold, temperate, and even subtropical regions. We conducted a non-systematic review of the causes and means of preventing accidental hypothermia after natural disasters caused by avalanches, earthquakes, tsunamis, and floods. Before a disaster occurs, preventive measures are required, such as accurate disaster risk analysis for given areas, hazard mapping and warning, protecting existing structures within hazard zones to the greatest extent possible, building structures outside hazard zones, and organising rapid and effective rescue. After the event, post hoc analyses of failures, and implementation of corrective actions will reduce the risk of accidental hypothermia in future disasters.

  View details for DOI 10.3390/ijerph19031098

  View details for PubMedID 35162119

• Prehospital Use of Ultrathin Reflective Foils. Wilderness & environmental medicine Kosinski, S., Podsiadlo, P., Darocha, T., Pasquier, M., Mendrala, K., Sanak, T., Zafren, K. 1800

  Abstract

  Ultrathin reflective foils (URFs) are widely used to protect patients from heat loss, but there is no clear evidence that they are effective. We review the physics of thermal insulation by URFs and discuss their clinical applications. A conventional view is that the high reflectivity of the metallic side of the URF is responsible for thermal protection. In most circumstances, the heat radiated from a well-clothed body is minimal and the reflecting properties of a URF are relatively insignificant. The reflection of radiant heat can be impaired by condensation and freezing of the moisture on the inner surface and by a tight fit of the URF against the outermost layer of insulation. The protection by thermal insulating materials depends mostly on the ability to trap air and increases with the number of covering layers. A URF as a single layer may be useful in low wind conditions and moderate ambient temperature, but in cold and windy conditions a URF probably best serves as a waterproof outer covering. When a URF is used to protect against hypothermia in a wilderness emergency, it does not matter whether the gold or silver side is facing outward.

  View details for DOI 10.1016/j.wem.2021.11.006

  View details for PubMedID 34998706

• Accidental Hypothermia: 2021 Update. International journal of environmental research and public health Paal, P., Pasquier, M., Darocha, T., Lechner, R., Kosinski, S., Wallner, B., Zafren, K., Brugger, H. 1800; 19 (1)

  Abstract

  Accidental hypothermia is an unintentional drop of core temperature below 35 °C. Annually, thousands die of primary hypothermia and an unknown number die of secondary hypothermia worldwide. Hypothermia can be expected in emergency patients in the prehospital phase. Injured and intoxicated patients cool quickly even in subtropical regions. Preventive measures are important to avoid hypothermia or cooling in ill or injured patients. Diagnosis and assessment of the risk of cardiac arrest are based on clinical signs and core temperature measurement when available. Hypothermic patients with risk factors for imminent cardiac arrest (temperature < 30 °C in young and healthy patients and <32 °C in elderly persons, or patients with multiple comorbidities), ventricular dysrhythmias, or systolic blood pressure < 90 mmHg) and hypothermic patients who are already in cardiac arrest, should be transferred directly to an extracorporeal life support (ECLS) centre. If a hypothermic patient arrests, continuous cardiopulmonary resuscitation (CPR) should be performed. In hypothermic patients, the chances of survival and good neurological outcome are higher than for normothermic patients for witnessed, unwitnessed and asystolic cardiac arrest. Mechanical CPR devices should be used for prolonged rescue, if available. In severely hypothermic patients in cardiac arrest, if continuous or mechanical CPR is not possible, intermittent CPR should be used. Rewarming can be accomplished by passive and active techniques. Most often, passive and active external techniques are used. Only in patients with refractory hypothermia or cardiac arrest are internal rewarming techniques required. ECLS rewarming should be performed with extracorporeal membrane oxygenation (ECMO). A post-resuscitation care bundle should complement treatment.

  View details for DOI 10.3390/ijerph19010501

  View details for PubMedID 35010760

• Ward, Milledge & West's High Altitude Medicine and Physiology, Sixth Edition (Book Review) WILDERNESS & ENVIRONMENTAL MEDICINE Book Review Authored by: Zafren, K. 2021; 32 (4): 561

  View details for Web of Science ID 000718694500026

• Higher pre-hospital anaesthesia case volumes result in lower mortality rates: implications for mass casualty care. British journal of anaesthesia Paal, P., Zafren, K., Pasquier, M. 2021

  Abstract

  Senior physicians with a higher pre-hospital anaesthesia case volume have higher first-pass tracheal intubation success rates, shorter on-site times, and lower patient mortality rates than physicians with lower case volumes. A senior physician's skill set includes the basics of management of airway and breathing (ventilating and oxygenating the patient), circulation, disability (anaesthesia), and environment (especially maintaining core temperature). Technical rescue skills may be required to care for patients requiring pre-hospital airway management especially in hazardous environments, such as road traffic accidents, chemical incidents, terror attacks or warfare, and natural disasters. Additional important tactical skills in mass casualty situations include patient triage, prioritising, allocating resources, and making transport decisions.

  View details for DOI 10.1016/j.bja.2021.10.022

  View details for PubMedID 34794765

• Nonfreezing Cold Injury (Trench Foot). International journal of environmental research and public health Zafren, K. 2021; 18 (19)

  Abstract

  Nonfreezing cold injury (NFCI) is a modern term for trench foot or immersion foot. Moisture is required to produce a NFCI. NFCI seldom, if ever, results in loss of tissue unless there is also pressure necrosis or infection. Much of the published material regarding management of NFCIs has been erroneously borrowed from the literature on warm water immersion injuries. NFCI is a clinical diagnosis. Most patients with NFCI have a history of losing feeling for at least 30 min and having pain or abnormal sensation on rewarming. Limbs with NFCI usually pass through four 'stages.' cold exposure, post-exposure (prehyperaemic), hyperaemic, and posthyperaemic. Limbs with NFCI should be cooled gradually and kept cool. Amitriptyline is likely the most effective medication for pain relief. If prolonged exposure to wet, cold conditions cannot be avoided, the most effective measures to prevent NFCI are to stay active, wear adequate clothing, stay well-nourished, and change into dry socks at least daily.

  View details for DOI 10.3390/ijerph181910482

  View details for PubMedID 34639782

• Resuscitation of an Unconscious Victim of Accidental Hyperthermia in 1805. Wilderness & environmental medicine Wallner, B., Giesbrecht, G., Pasquier, M., Gordon, L., Lechner, R., Brugger, H., Paal, P., Darocha, T., Zafren, K. 2021

  Abstract

  In 1805, W.D., a 16-y-old boy, became hypothermic after he was left alone on a grounded boat in Leith Harbour, near Edinburgh, Scotland. He was brought to his own house and resuscitated with warm blankets, smelling salts, and massage by Dr. George Kellie. W.D. made an uneventful recovery. We discuss the pathophysiology and treatment of accidental hypothermia, contrasting treatment in 1805 with treatment today. W.D. was hypothermic when found by passersby. Although he appeared dead, he was rewarmed with help from Dr. Kellie and his assistants over 200 y ago using simple methods. One concept that has not changed is the critical importance of attempting resuscitation, even if it seems to be futile. Don't give up!

  View details for DOI 10.1016/j.wem.2021.08.007

  View details for PubMedID 34620550

• A Shocking Experience WILDERNESS & ENVIRONMENTAL MEDICINE Marino, R., Martinez, I., Gozalo, M., Zafren, K. 2021; 32 (3): 383-384

  View details for Web of Science ID 000692620800018

• A Shocking Experience. Wilderness & environmental medicine Marino, R. B., Martinez, I. S., Panos Gozalo, M. L., Zafren, K. 2021

  View details for DOI 10.1016/j.wem.2021.04.003

  View details for PubMedID 34083095

• Reply to: Revised Swiss System for clinical staging of accidental hypothermia - At which core temperatures are patients at high risk of cardiac arrest? Resuscitation Musi, M. E., Sheets, A., Brugger, H., Paal, P., Zafren, K., Pasquier, M. 2021

  View details for DOI 10.1016/j.resuscitation.2021.05.014

  View details for PubMedID 34082033

• Warm Fluid Infusion Is Not an Effective Primary Warming Method in Accidental Hypothermia. Therapeutic hypothermia and temperature management Pasquier, M., Gordon, L., Paal, P., Darocha, T., Zafren, K. 2021

  View details for DOI 10.1089/ther.2021.0006

  View details for PubMedID 33887159

• Clinical staging of accidental hypothermia: the Revised Swiss System: Recommendation of the International Commission for Mountain Emergency Medicine (ICAR MedCom). Resuscitation Musi, M. E., Sheets, A., Zafren, K., Brugger, H., Paal, P., Holzl, N., Pasquier, M. 2021

  Abstract

  Clinical staging of accidental hypothermia is used to guide out-of-hospital treatment and transport decisions. Most clinical systems utilize core temperature, by measurement or estimation, to stage hypothermia, despite the challenge of obtaining accurate field measurements. Recent studies have demonstrated that field estimation of core temperature is imprecise. We propose a revision of the original Swiss Staging system. The revised system uses the risk of cardiac arrest, instead of core temperature, to determine the staging level. Our revised system simplifies assessment by using the level of responsiveness, based on the AVPU scale, and by removing shivering as a stage-defining sign.

  View details for DOI 10.1016/j.resuscitation.2021.02.038

  View details for PubMedID 33675869

• Witnessed Cardiac Arrest in a Hypothermic Avalanche Victim Completely Buried for 2 Hours WILDERNESS & ENVIRONMENTAL MEDICINE Daniel, N., Weinberg, N., Carus, F., Church, B., Zafren, K. 2021; 32 (1): 92–97

  View details for Web of Science ID 000633495100016

• The Light Is Gone: Tribute to Prakash Adhikari, Executive Director of the Himalayan Rescue Association. High altitude medicine & biology Basnyat, B., Freer, L., Zafren, K. 2021

  View details for DOI 10.1089/ham.2020.0213

  View details for PubMedID 33625264

• Witnessed Cardiac Arrest in a Hypothermic Avalanche Victim Completely Buried for 2 Hours. Wilderness & environmental medicine Daniel, N., Weinberg, N., Carus, F., Church, B., Zafren, K. 2021

  Abstract

  A 34-y-old skier triggered a wind slab avalanche and was completely buried for over 2 h. After extrication by rescuers, the victim was breathing and conscious. Despite directions from the rescuers against standing up, the victim struggled to free himself and ultimately stood upright before collapsing in cardiac arrest. The rescuers performed cardiopulmonary resuscitation during transport to a nearby trailhead, where a helicopter emergency medical services crew found that the victim was in ventricular fibrillation. After further resuscitative efforts, including advanced life support, the victim was declared dead at the scene. Afterdrop and circumrescue collapse were the most likely triggers of cardiac arrest. This case highlights a need for rescuers, emergency medical services, and hospitals to be prepared to care for victims with hypothermia. To prevent circumrescue collapse, victims with hypothermia should be extricated gently, should not be allowed to stand, and should be placed flat. This may be difficult or impossible, as in this case. Hypothermic victims in cardiac arrest may require prolonged cardiopulmonary resuscitation, preferably with mechanical compressions, during transport to a hospital that has protocols for rewarming using extracorporeal life support. Resuscitation from hypothermic cardiac arrest should not be terminated before the victim has been rewarmed.

  View details for DOI 10.1016/j.wem.2020.10.007

  View details for PubMedID 33518494

• Effects of Climate Change on Avalanche Accidents and Survival. Frontiers in physiology Strapazzon, G., Schweizer, J., Chiambretti, I., Brodmann Maeder, M., Brugger, H., Zafren, K. 2021; 12: 639433

  Abstract

  Avalanches are major natural hazards in snow-covered mountains, threatening people and infrastructure. With ongoing climate change, the frequency and types of snow avalanches may change, affecting the rates of avalanche burial and survival. With a wetter and warmer snow climate, consequences of burial may become more severe. In this review, we assess the potential effects of climate change on the frequency and characteristics of avalanches. We then discuss how these changes might affect the survival rates of subjects buried by avalanches and might influence the responses of search and rescue (SAR) teams and health care providers. While climate change is inevitable, the effects on avalanches remain elusive. The frequency of human triggered avalanches may not change, because this depends largely on the number and behavior of winter recreationists. Blunt trauma and secondary injuries will likely become more frequent as terrain roughness is expected to rise and snow cover to become thinner. Higher snow densities in avalanche debris will likely interfere with the respiration of completely buried victims. Asphyxia and trauma, as causes of avalanche death, may increase. It is unlikely that SAR and health care providers involved in avalanche rescue will have to change their strategies in areas where they are already established. The effects of climate change might foster the expansion of mitigation strategies and the establishment of mountain rescue services in areas subject to increased avalanche hazards caused by changes in snow cover and land use.

  View details for DOI 10.3389/fphys.2021.639433

  View details for PubMedID 33912070

• Quality Indicators for Avalanche Victim Management and Rescue. International journal of environmental research and public health Kottmann, A., Pasquier, M., Strapazzon, G., Zafren, K., Ellerton, J., Paal, P. 2021; 18 (18)

  Abstract

  Decisions in the management and rescue of avalanche victims are complex and must be made in difficult, sometimes dangerous, environments. Our goal was to identify indicators for quality measurement in the management and rescue of avalanche victims. The International Commission for Mountain Emergency Medicine (ICAR MedCom) convened a group of internal and external experts. We used brainstorming and a five-round modified nominal group technique to identify the most relevant quality indicators (QIs) according to the National Quality Forum Measure Evaluation Criteria. Using a consensus process, we identified a set of 23 QIs to measure the quality of the management and rescue of avalanche victims. These QIs may be a valuable tool for continuous quality improvement. They allow objective feedback to rescuers regarding clinical performance and identify areas that should be the foci of further quality improvement efforts in avalanche rescue.

  View details for DOI 10.3390/ijerph18189570

  View details for PubMedID 34574495

• Vitals Signs in Accidental Hypothermia. High altitude medicine & biology Pasquier, M., Cools, E., Zafren, K., Carron, P., Frochaux, V., Rousson, V. 2020

  Abstract

  Pasquier, Mathieu, Evelien Cools, Ken Zafren, Pierre-Nicolas Carron, Vincent Frochaux, and Valentin Rousson. Vitals signs in accidental hypothermia. High Alt Med Biol 00:000-000, 2020. Background: Clinical indicators are used to stage hypothermia and to guide management of hypothermic patients. We sought to better characterize the influence of hypothermia on vital signs, including level of consciousness, by studying cases of patients suffering from accidental hypothermia. Materials and Methods: We retrospectively included patients aged ≥18 years admitted to the hospital with a core temperature below 35°C. We identified the cases from a literature review and from a retrospective case series of hypothermic patients admitted to the hospital between 1994 and 2016. Patients who experienced cardiac arrest, as well as those with potential confounders such as concomitant diseases or intoxications, were excluded. Relationships between core temperature and heart rate, systolic blood pressure, respiratory rate, and level of consciousness were explored via correlations and regression. Results: Of the 305 cases reviewed, 216 met the criteria for inclusion. The mean temperature was 29.7°C±4.2°C (range 19.3°C-34.9°C). The relationships between temperature and each of the four vital signs were generally linear and significantly positive, with Spearman correlations for respiratory rate, heart rate, systolic blood pressure, and Glasgow Coma Score (GCS) of 0.29 (p=0.024), 0.44 (p<0.001), 0.47 (p<0.001), and 0.78 (p<0.001), respectively. Based on linear regression, the mean decrease of a vital sign associated with a 1°C decrease of temperature was estimated to be 0.50 minute-1 for respiratory rate, 2.54 minutes-1 for heart rate, 4.36mmHg for systolic blood pressure, and 0.88 for GCS. Conclusions: There is a significant positive correlation between core temperature and heart rate, systolic blood pressure, respiratory rate, and GCS. The relationship between vital signs and temperature is generally linear. This knowledge might help clinicians make appropriate decisions when determining whether the clinical condition of a patient should be attributed to hypothermia. This could enhance clinical care and help to guide future research.

  View details for DOI 10.1089/ham.2020.0179

  View details for PubMedID 33629884

• Are mobile ECMO teams necessary to treat severe accidental hypothermia? Resuscitation Brugger, H., Paal, P., Zafren, K., Strapazzon, G., Musi, M. E. 2020

  View details for DOI 10.1016/j.resuscitation.2020.11.032

  View details for PubMedID 33278520

• Determination of Death in Mountain Rescue: Recommendations of the International Commission for Mountain Emergency Medicine (ICAR MedCom) WILDERNESS & ENVIRONMENTAL MEDICINE Schoen, C. A., Gordon, L., Hoelzl, N., Milani, M., Paal, P., Zafren, K. 2020; 31 (4): 506–20

  View details for Web of Science ID 000600747000019

• Determination of Death in Mountain Rescue: Recommendations of the International Commission for Mountain Emergency Medicine (ICAR MedCom). Wilderness & environmental medicine Schon, C. A., Gordon, L., Holzl, N., Milani, M., Paal, P., Zafren, K. 2020

  Abstract

  Determination of death requires specific knowledge, training, and experience in most cases. It can be particularly difficult when external conditions, such as objective hazards in mountains, prevent close physical examination of an apparently lifeless person, or when examination cannot be accomplished by an authorized person. Guidelines exist, but proper use can be difficult. In addition to the absence of vital signs, definitive signs of death must be present. Recognition of definitive signs of death can be problematic due to the variability in time course and the possibility of mimics. Only clear criteria such as decapitation or detruncation should be used to determine death from a distance or by laypersons who are not medically trained. To present criteria that allow for accurate determination of death in mountain rescue situations, the International Commission for Mountain Emergency Medicine convened a panel of mountain rescue doctors and a forensic pathologist. These recommendations are based on a nonsystematic review of the literature including articles on determination of death and related topics.

  View details for DOI 10.1016/j.wem.2020.06.013

  View details for PubMedID 33077333

• Induced Hypothermia to 4.2 degrees C with Neurologically Intact Survival: A Forgotten Case Series WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K., Paal, P., Brugger, H., Lechner, R. 2020; 31 (3): 367–70

  View details for Web of Science ID 000577527800016

• Evidence-Based Versus Myth-Based Treatment of Suspension Syndrome WILDERNESS & ENVIRONMENTAL MEDICINE Mortimer, R. B., Zafren, K. 2020; 31 (2): 202–3

  View details for Web of Science ID 000542970800011

• Induced Hypothermia to 4.2°C with Neurologically Intact Survival: A Forgotten Case Series. Wilderness & environmental medicine Zafren, K., Paal, P., Brugger, H., Lechner, R. 2020

  Abstract

  The lowest recorded core temperature from which a person with accidental hypothermia has survived neurologically intact is 11.8°C in a 2-y-old boy. The lowest recorded temperature from which an adult has been resuscitated neurologically intact is 13.7°C in a 29-y-old woman. The lowest core temperature with survival from induced hypothermia has been quoted as 9°C. We discovered a case series (n=50) from 1961 in which 5 patients with core temperatures below 11.8°C survived neurologically intact. The lowest core temperature in this group was 4.2°C. The authors also presented cardiovascular and other physiologic data at various core temperatures. The patients in the case series showed a wide variation in individual physiological responses to hypothermia. It is not known whether survival from accidental hypothermia is possible with a core temperature below 11.8°C, but this case series suggests that the lower limit for successful resuscitation may be far lower. We advise against using core temperature alone to decide whether a hypothermic patient in cardiac arrest has a chance of survival.

  View details for DOI 10.1016/j.wem.2020.02.003

  View details for PubMedID 32482520

• Prakash Adhikari: April 13, 1965 to October 23, 2020 WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K., Basnyat, B., Baniya, S., Bashyal, G., Brugger, H., Dawadi, S., Freer, L., Johnson, E., Systermans, B. 2020; 32 (1): 6-11

  View details for Web of Science ID 000633495000001

• Data and methods to calculate cut-off values for serum potassium and core temperature at hospital admission for extracorporeal rewarming of avalanche victims in cardiac arrest. Data in brief Falk, M. n., Brugger, H. n., Bouzat, P. n., Pasquier, M. n., Mair, P. n., Fieler, J. n., Darocha, T. n., Blancher, M. n., de Riedmatten, M. n., Paal, P. n., Strapazzon, G. n., Zafren, K. n., Brodmann Maeder, M. n. 2020; 28: 104913

  Abstract

  The data and estimation methods presented in this article are associated with the research article, "Cut-off values of serum potassium and core temperature at hospital admission for extracorporeal rewarming of avalanche victims in cardiac arrest: a retrospective multi-centre study" [1]. In this article we estimate recommended cut-off values for in-hospital triage with respect to extracorporeal rewarming. With only 6 survivors of 103 patients collected over a period of 20 years the ability to estimate reliable threshold values is limited. In addition, because the number of avalanche victims is also limited, a significantly larger dataset is unlikely to be obtained. We have therefore adapted two non-parametric estimation methods (bootstrapping and exact binomial distribution) to our specific needs and performed a simulations to confirm validity and reliability.

  View details for DOI 10.1016/j.dib.2019.104913

  View details for PubMedID 31890782

  View details for PubMedCentralID PMC6926115

• Advancing The Evidence In Altitude And Wilderness Medicine. Journal of travel medicine Zafren, K. n., Shlim, D. R., Basnyat, B. n., Visser, J. n. 2020

  View details for DOI 10.1093/jtm/taaa129

  View details for PubMedID 32761151

• Sunscreen for Adventure Travel: Use Sun Protection Factor (SPF) 50 or Higher. Journal of travel medicine Zafren, K. n. 2020

  View details for DOI 10.1093/jtm/taaa048

  View details for PubMedID 32299101

• Wilderness Medical Society Clinical Practice Guidelines forthe Out-of-Hospital Evaluation and Treatment of Accidental Hypothermia: 2019 Update. Wilderness & environmental medicine Dow, J., Giesbrecht, G. G., Danzl, D. F., Brugger, H., Sagalyn, E. B., Walpoth, B., Auerbach, P. S., McIntosh, S. E., Nemethy, M., McDevitt, M., Schoene, R. B., Rodway, G. W., Hackett, P. H., Zafren, K., Bennett, B. L., Grissom, C. K. 2019

  Abstract

  To provide guidance to clinicians, the Wilderness Medical Society convened an expert panel to develop evidence-based guidelines for the out-of-hospital evaluation and treatment of victims of accidental hypothermia. The guidelines present the main diagnostic and therapeutic modalities and provide recommendations for the management of hypothermic patients. The panel graded the recommendations based on the quality of supporting evidence and a balance between benefits and risks/burdens according to the criteria published by the American College of Chest Physicians. The guidelines also provide suggested general approaches to the evaluation and treatment of accidental hypothermia that incorporate specific recommendations. This is the 2019 update of the Wilderness Medical Society Practice Guidelines for the Out-of-Hospital Evaluation and Treatment of Accidental Hypothermia: 2014 Update.

  View details for DOI 10.1016/j.wem.2019.10.002

  View details for PubMedID 31740369

• Emergency Airways After Himalayan Black Bear Attacks in Bhutan. Wilderness & environmental medicine Mize, C. H., Dorji, L., Zafren, K. 2019

  Abstract

  INTRODUCTION: Although bear attacks on humans are uncommon, the incidence has slowly risen as human populations increasingly encroach on wilderness habitat. In the Kingdom of Bhutan, Himalayan black bear attacks occur regularly. Bears preferentially attack the face, often causing injuries that require surgical airway management. We sought to determine how often patients injured by Himalayan black bears required airway management during initial resuscitation.METHODS: We conducted a retrospective review of emergency department and admission records of the 3 referral hospitals in Bhutan. We identified all victims of bear attacks in Bhutan who received emergency airway management, including surgical airway management during the period from August 2013 to December 2017.RESULTS: There were 21 patients who were treated for injuries from bear attacks during the study period. Of these, 12 required emergency airway management. Three patients who required emergency airways (2 intubations, 1 surgical airway) were attacked near a regional referral hospital and received care at that hospital. The remaining 9 patients received care from the helicopter emergency medical services (HEMS) retrieval team (1 intubation, 8 surgical airways).CONCLUSIONS: The use of highly trained HEMS critical care retrieval teams may improve outcomes in critically injured patients who require time-critical airway management in remote areas. Countries such as Bhutan with populations far from emergency and critical care might benefit from the establishment of HEMS critical care retrieval services. HEMS teams providing care while retrieving patients from austere environments should be expert in emergency airway management.

  View details for DOI 10.1016/j.wem.2019.08.003

  View details for PubMedID 31672511

• Pediatric High Altitude Cerebral Edema in the Nepal Himalayas. Wilderness & environmental medicine Church, B. J., Basnyat, B., Mattingly, B., Zafren, K. 2019

  Abstract

  High altitude cerebral edema (HACE) is a rare complication of ascent to altitudes of over 2500 m (8200 ft). We are not aware of a previously published case report of HACE in a patient under the age of 18 y. We report on 2 cases of suspected HACE in 2 patients, aged 12 and 16 y, who presented to the Manang Himalayan Rescue Association clinic at 3500 m. The 16-y-old patient presented with severe headache, vomiting, and ataxia after rapid ascent to 3800 m. The 12-y-old patient presented with severe headache, vomiting, visual disturbances, and ataxia at 4500 m, which began to resolve with descent to the clinic at 3500 m. Our cases suggest that HACE can occur in children and adolescents. Because there are no specific guidelines for treatment of acute mountain sickness or HACE in patients under the age of 18 y, we recommend treatment as for adults: oxygen, immediate descent, and dexamethasone. Simulated descent in a portable hyperbaric chamber can be used if oxygen is not available and if actual descent is not possible.

  View details for DOI 10.1016/j.wem.2019.05.003

  View details for PubMedID 31301992

• Successful Field Rewarming of a Patient with Apparent Moderate Hypothermia Using a Hypothermia Wrap and a Chemical Heat Blanket WILDERNESS & ENVIRONMENTAL MEDICINE Phillips, D., Bowman, J., Zafren, K. 2019; 30 (2): 199–202

  View details for DOI 10.1016/j.wem.2019.01.001

  View details for Web of Science ID 000472986100014

• Cut-off values of serum potassium and core temperature at hospital admission for extracorporeal rewarming of avalanche victims in cardiac arrest: A retrospective multi-centre study RESUSCITATION Brugger, H., Bouzat, P., Pasquier, M., Mair, P., Fieler, J., Darocha, T., Blancher, M., de Riedmatten, M., Falk, M., Paal, P., Strapazzon, G., Zafren, K., Maeder, M. 2019; 139: 222–29

  View details for DOI 10.1016/j.resuscitation.2019.04.025

  View details for Web of Science ID 000470076000029

• Successful Field Rewarming of a Patient with Apparent Moderate Hypothermia Using a Hypothermia Wrap and a Chemical Heat Blanket. Wilderness & environmental medicine Phillips, D., Bowman, J., Zafren, K. 2019

  Abstract

  Hypothermia is a common problem encountered by search and rescue teams. Although mildly hypothermic patients can be rewarmed in the field and can then self-evacuate, the Wilderness Medical Society hypothermia guidelines suggest that a moderately hypothermic patient in the wilderness requires warming in a medical facility. The Hypothermia Prevention and Management Kit, developed by the US military, consists of a chemical heat blanket (CHB) and a heat-reflective shell. We present a case in which a hypothermia wrap and the CHB from a Hypothermia Prevention and Management Kit were used successfully to rewarm a patient with apparent moderate hypothermia in the field. We are unaware of previous reports of successful field rewarming of a patient with moderate hypothermia. We believe the use of the CHB in conjunction with a hypothermia wrap made field rewarming possible. We recommend that a CHB, along with the components of a hypothermia wrap, be carried by search and rescue teams when a hypothermic patient might be encountered. Although there were no documented core temperatures, we believe this case is consistent with the hypothesis that if a hypothermic patient who is found lying down and shivering is allowed to stand or walk before insulation is applied and before there has been an additional period of 30 min during which the patient continues to shiver, there may be increased afterdrop with deleterious results.

  View details for PubMedID 30824366

• Cut-off values of serum potassium and core temperature at hospital admission for extracorporeal rewarming of avalanche victims in cardiac arrest: A retrospective multi-centre study. Resuscitation Brugger, H. n., Bouzat, P. n., Pasquier, M. n., Mair, P. n., Fieler, J. n., Darocha, T. n., Blancher, M. n., de Riedmatten, M. n., Falk, M. n., Paal, P. n., Strapazzon, G. n., Zafren, K. n., Brodmann Maeder, M. n. 2019

  Abstract

  Evidence of existing guidelines for the on-site triage of avalanche victims is limited and adherence suboptimal. This study attempted to find reliable cut-off values for the identification of hypothermic avalanche victims with reversible out-of-hospital cardiac arrest (OHCA) at hospital admission. This may enable hospitals to allocate ECLS resources more appropriately while increasing the proportion of survivors among rewarmed victims.All avalanche victims with OHCA admitted to seven centres in Europe capable of ECLS from 1995 to 2016 were included. Optimal cut-off values, for parameters identified by logistic regression, were determined by means of bootstrapping and exact binomial distribution and served to calculate sensitivity, rate of overtriage, positive and negative predictive values, and receiver operating curves.In total, 103 avalanche victims with OHCA were included. Of the 103 patients 61 (58%) were rewarmed by ECLS. Six (10%) of the rewarmed patients survived whilst 55 (90%) died. We obtained optimal cut-off values of 7 mmol/L for serum potassium and 30 °C for core temperature.For in-hospital triage of avalanche victims admitted with OHCA, serum potassium accurately predicts survival. The combination of the cut-offs 7 mmol/L for serum potassium and 30 °C for core temperature achieved the lowest overtriage rate (47%) and the highest positive predictive value (19%), with a sensitivity of 100% for survivors. The presence of vital signs at extrication is strongly associated with survival. For further optimisation of in-hospital triage, larger datasets are needed to include additional parameters.

  View details for PubMedID 31022496

• Helicopter Critical Care Retrieval in a Developing Country: A Trauma Case Series from Bhutan. High altitude medicine & biology Mize, C. H., Evers, E. S., Dorji, L. n., Zafren, K. n. 2019

  Abstract

  Mize, Charles Haviland, Egmond Samir Evers, Lhab Dorji, and Ken Zafren. Helicopter critical care retrieval in a developing country: A trauma case series from Bhutan. High Alt Med Biol. 00:000-000, 2019. Background: The care of victims of traumatic injuries requires an organized system to achieve the best outcomes. Dispatch of specialist physicians, paramedics, and nurses to the patient by helicopter can reduce mortality. Countries in the developing world share the challenge of providing timely medical care to trauma victims, while facing others such as a higher trauma burden, poor infrastructure, inadequate government resources, organizational constraints, a lack of technical expertise, and prohibitive costs. These challenges can severely limit the provision of critical prehospital trauma care. Methods: We reviewed the prehospital trauma database to identify victims of trauma who required aeromedical evacuation as determined by the national triage system of Bhutan during the 4-month period after the establishment of the national Bhutan Emergency Aeromedical Retrieval (BEAR) team. We collected the patients' age and gender, description of injuries, mechanism of injury, interventions undertaken by the critical care retrieval team, and patient outcomes (alive vs. dead). Results: During the first 4 months of service, BEAR cared for 16 trauma patients. Fourteen patients survived to hospital discharge; two died after hospitalization. No patient died on scene or during transport. The team successfully treated several challenging casualties, including a patient gored by a water buffalo leading to traumatic cardiac arrest with successful resuscitation, victims of a compressed gas cylinder explosion, a bear mauling, and a penetrating arrow injury to the head. The team performed a variety of critical care interventions, including induction and maintenance of anesthesia, orotracheal intubation, mechanical ventilation, tube thoracostomy, administration of blood products, and successful management of traumatic cardiac arrest. Conclusion: A critical care helicopter retrieval team can deliver trauma care in a developing country, such as Bhutan, with favorable outcomes at low cost.

  View details for DOI 10.1089/ham.2019.0019

  View details for PubMedID 31460794

• Prehospital administration of surfactant to a premature neonate in respiratory distress. Scandinavian journal of trauma, resuscitation and emergency medicine Mize, C. H., Dorji, L. n., Zafren, K. n. 2019; 27 (1): 95

  Abstract

  The population of the Kingdom of Bhutan is scattered in small villages throughout the eastern Himalaya. Infants born prematurely in villages have no access to neonatal intensive care until they are transported to the national referral hospital, a process that once took hours, if not days. After the introduction of a helicopter critical-care retrieval team, we were able to send a trained team to a remote location that successfully administered surfactant and initiated critical care to a premature, extreme low birth weight infant in severe respiratory distress in the first hour of life. Although the infant was in shock and in a near-arrest state at the time the team arrived, he made an excellent recovery after resuscitation by the team.

  View details for DOI 10.1186/s13049-019-0664-9

  View details for PubMedID 31665094

• Wilderness Medical Society Practice Guidelines for the Prevention and Treatment of Acute Altitude Illness: 2019 Update. Wilderness & environmental medicine Luks, A. M., Auerbach, P. S., Freer, L. n., Grissom, C. K., Keyes, L. E., McIntosh, S. E., Rodway, G. W., Schoene, R. B., Zafren, K. n., Hackett, P. H. 2019

  Abstract

  To provide guidance to clinicians about best preventive and therapeutic practices, the Wilderness Medical Society (WMS) convened an expert panel to develop evidence-based guidelines for prevention and treatment of acute mountain sickness, high altitude cerebral edema, and high altitude pulmonary edema. Recommendations are graded based on the quality of supporting evidence and the balance between the benefits and risks/burdens according to criteria put forth by the American College of Chest Physicians. The guidelines also provide suggested approaches to prevention and management of each form of acute altitude illness that incorporate these recommendations. This is an updated version of the original WMS Consensus Guidelines for the Prevention and Treatment of Acute Altitude Illness published in 2010 and subsequently updated as the WMS Practice Guidelines for the Prevention and Treatment of Acute Altitude Illness in 2014.

  View details for DOI 10.1016/j.wem.2019.04.006

  View details for PubMedID 31248818

• Wilderness Mass Casualty Incident (MCI): Rescue Chain After Avalanche at Everest Base Camp (EBC) In 2015 WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K., Brants, A., Tabner, K., Nyberg, A., Pun, M., Basnyat, B., Maeder, M. 2018; 29 (3): 401–10

  View details for DOI 10.1016/j.wem.2018.03.007

  View details for Web of Science ID 000445975900017

• Reported Resuscitation of a Hypothermic Avalanche Victim With Assisted Ventilation in 1939. Wilderness & environmental medicine Zafren, K., Atkins, D., Brugger, H. 2018; 29 (2): 275–77

  Abstract

  We present a historical case of a 12-year-old boy who survived a reported avalanche burial in 1939 in the Upper Peninsula of Michigan. The boy was completely buried for at least 3 h, head down, at a depth of about 1 m. He was extricated without signs of life and likely hypothermic by his father, who took him to his home. There, the father performed assisted ventilation for 3 hours using the Schafer method, a historical method of artificial ventilation, without any specific rewarming efforts. The boy recovered neurologically intact. This case illustrates the importance of attempting resuscitation, possibly prolonged, of victims of hypothermia, even those who are apparently dead.

  View details for PubMedID 29599095

• International Commission for Mountain Emergency Medicine Consensus Guidelines for On-Site Management and Transport of Patients in Canyoning Incidents WILDERNESS & ENVIRONMENTAL MEDICINE Strapazzon, G., Reisten, O., Argenone, F., Zafren, K., Zen-Ruffinen, G., Larsen, G. L., Soteras, I. 2018; 29 (2): 252–65

  Abstract

  Canyoning is a recreational activity that has increased in popularity in the last decade in Europe and North America, resulting in up to 40% of the total search and rescue costs in some geographic locations. The International Commission for Mountain Emergency Medicine convened an expert panel to develop recommendations for on-site management and transport of patients in canyoning incidents. The goal of the current review is to provide guidance to healthcare providers and canyoning rescue professionals about best practices for rescue and medical treatment through the evaluation of the existing best evidence, focusing on the unique combination of remoteness, water exposure, limited on-site patient management options, and technically challenging terrain. Recommendations are graded on the basis of quality of supporting evidence according to the classification scheme of the American College of Chest Physicians.

  View details for PubMedID 29422373

• Management of Multi-Casualty Incidents in Mountain Rescue: Evidence-Based Guidelines of the International Commission for Mountain Emergency Medicine (ICAR MEDCOM) HIGH ALTITUDE MEDICINE & BIOLOGY Blancher, M., Albasini, F., Elsensohn, F., Zafren, K., Hoelzl, N., McLaughlin, K., Wheeler, A. R., Roy, S., Brugger, H., Greene, M., Paal, P. 2018

  Abstract

  Blancher, Marc, François Albasini, Fidel Elsensohn, Ken Zafren, Natalie Hölzl, Kyle McLaughlin, Albert R. Wheeler III, Steven Roy, Hermann Brugger, Mike Greene, and Peter Paal. Management of multi-casualty incidents in mountain rescue. High Alt Med Biol. 00:000-000, 2018.Multi-Casualty Incidents (MCI) occur in mountain areas. Little is known about the incidence and character of such events, and the kind of rescue response. Therefore, the International Commission for Mountain Emergency Medicine (ICAR MEDCOM) set out to provide recommendations for the management of MCI in mountain areas.Details of MCI occurring in mountain areas related to mountaineering activities and involving organized mountain rescue were collected. A literature search using (1) PubMed, (2) national mountain rescue registries, and (3) lay press articles on the internet was performed. The results were analyzed with respect to specific aspects of mountain rescue.We identified 198 MCIs that have occurred in mountain areas since 1956: 137 avalanches, 38 ski lift accidents, and 23 other events, including lightning injuries, landslides, volcanic eruptions, lost groups of people, and water-related accidents.General knowledge on MCI management is required. Due to specific aspects of triage and management, the approach to MCIs may differ between those in mountain areas and those in urban settings.Mountain rescue teams should be prepared to manage MCIs. Knowledge should be reviewed and training performed regularly. Cooperation between terrestrial rescue services, avalanche safety authorities, and helicopter crews is critical to successful management of MCIs in mountain areas.

  View details for PubMedID 29446647

• In Response to Ibuprofen vs Acetaminophen in AMS Prevention by Kanaan et al Reply WILDERNESS & ENVIRONMENTAL MEDICINE Kanaan, N. C., Peterson, A. L., Pun, M., Thapa, G. B., Tiwari, A., Basyal, B., Holck, P. S., Starling, J., Freeman, T. F., Gehner, J. R., Keyes, L., Levin, D. R., O'Leary, C. J., Stuart, K. E., Velgersdyk, J. L., Zafren, K., Basnyat, B. 2017; 28 (4): 385–87

  View details for PubMedID 29110912

• Yarsagumba Fungus: Health Problems in the Himalayan Gold Rush WILDERNESS & ENVIRONMENTAL MEDICINE Koirala, P., Pandit, B., Phuyal, P., Zafren, K. 2017; 28 (3): 267–70

  Abstract

  Seasonal migration of people in search of Yarsagumba fungus creates a population of collectors that faces hardship and health risks in austere high-altitude settings.In 2016, our 4-person team performed a 2-day health-needs survey of people collecting Yarsagumba fungus near the village of Yak Kharka (4020 m) in the Manang District of Nepal.There were approximately 800 people, both male and female, from age 10 to over 60, collecting Yarsagumba fungus. They had paid high prices for permits, hoping to recoup the cost and make a profit by selling specimens of Yarsagumba, but the fungus seemed scarce in 2016, resulting in a bleak economic forecast. Most collectors were living in austere conditions, walking long hours to the collection areas early in the morning and returning in the late afternoon. Most were subsisting on 1 daily meal. Health problems, including acute mountain sickness as well as respiratory and gastrointestinal illnesses, were common. Yarsagumba has become harder to find in recent years, increasing hardships and risk of injury. Medical care was almost nonexistent.As abundance decreases and demand increases, there is increasing pressure on collectors to find Yarsagumba. The collectors are an economically disadvantaged population who live in austere conditions at high altitude with poor shelter and sanitation, strenuous work, and limited availability of food. Health care resources are very limited. There are significant risks of illness, injury, and death. Targeted efforts by government entities and nongovernmental organizations might be beneficial in meeting the health needs.

  View details for PubMedID 28716290

• Prophylactic Acetaminophen or Ibuprofen Result in Equivalent Acute Mountain Sickness Incidence at High Altitude: A Prospective Randomized Trial. Wilderness & environmental medicine Kanaan, N. C., Peterson, A. L., Pun, M., Holck, P. S., Starling, J., Basyal, B., Freeman, T. F., Gehner, J. R., Keyes, L., Levin, D. R., O'Leary, C. J., Stuart, K. E., Thapa, G. B., Tiwari, A., Velgersdyk, J. L., Zafren, K., Basnyat, B. 2017

  Abstract

  Recent trials have demonstrated the usefulness of ibuprofen in the prevention of acute mountain sickness (AMS), yet the proposed anti-inflammatory mechanism remains unconfirmed. Acetaminophen and ibuprofen were tested for AMS prevention. We hypothesized that a greater clinical effect would be seen from ibuprofen due to its anti-inflammatory effects compared with acetaminophen's mechanism of possible symptom reduction by predominantly mediating nociception in the brain.A double-blind, randomized trial was conducted testing acetaminophen vs ibuprofen for the prevention of AMS. A total of 332 non-Nepali participants were recruited at Pheriche (4371 m) and Dingboche (4410 m) on the Everest Base Camp trek. The participants were randomized to either acetaminophen 1000 mg or ibuprofen 600 mg 3 times a day until they reached Lobuche (4940 m), where they were reassessed. The primary outcome was AMS incidence measured by the Lake Louise Questionnaire score.Data from 225 participants who met inclusion criteria were analyzed. Twenty-five participants (22.1%) in the acetaminophen group and 18 (16.1%) in the ibuprofen group developed AMS (P = .235). The combined AMS incidence was 19.1% (43 participants), 14 percentage points lower than the expected AMS incidence of untreated trekkers in prior studies at this location, suggesting that both interventions reduced the incidence of AMS.We found little evidence of any difference between acetaminophen and ibuprofen groups in AMS incidence. This suggests that AMS prevention may be multifactorial, affected by anti-inflammatory inhibition of the arachidonic-acid pathway as well as other analgesic mechanisms that mediate nociception. Additional study is needed.

  View details for DOI 10.1016/j.wem.2016.12.011

  View details for PubMedID 28479001

• Out-of-Hospital Evaluation and Treatment of Accidental Hypothermia EMERGENCY MEDICINE CLINICS OF NORTH AMERICA Zafren, K. 2017; 35 (2): 261-?

  Abstract

  Accidental hypothermia is an unintentional drop in core temperature to 35°C or below. Core temperature is best measured by esophageal probe. If core temperature cannot be measured, the degree should be estimated using clinical signs. Treatment is to protect from further heat loss, minimize afterdrop, and prevent cardiovascular collapse during rescue and resuscitation. The patient should be handled gently, kept horizontal, insulated, and actively rewarmed. Active rewarming is also beneficial in mild hypothermia but passive rewarming usually suffices. Cardiopulmonary resuscitation should be performed if there are no contraindications to resuscitation. CPR may be delayed or intermittent.

  View details for DOI 10.1016/j.emc.2017.01.003

  View details for PubMedID 28411927

• Wilderness Medical Society Practice Guidelines for Prevention and Management of Avalanche and Nonavalanche Snow Burial Accidents. Wilderness & environmental medicine Van Tilburg, C., Grissom, C. K., Zafren, K., McIntosh, S., Radwin, M. I., Paal, P., Haegeli, P., Smith, W. W., Wheeler, A. R., Weber, D., Tremper, B., Brugger, H. 2017; 28 (1): 23-42

  Abstract

  To provide guidance to clinicians and avalanche professionals about best practices, the Wilderness Medical Society convened an expert panel to develop evidence-based guidelines for the prevention, rescue, and medical management of avalanche and nonavalanche snow burial victims. Recommendations are graded on the basis of quality of supporting evidence according to the classification scheme of the American College of Chest Physicians.

  View details for DOI 10.1016/j.wem.2016.10.004

  View details for PubMedID 28257714

• Mountain Medicine and Technical Rescue (Book Review) HIGH ALTITUDE MEDICINE & BIOLOGY Book Review Authored by: Zafren, K. 2017; 18 (1): 82–83

  View details for PubMedID 28112542

• Subtle Cognitive Dysfunction in Resolving High Altitude Cerebral Edema Revealed by a Clock Drawing Test WILDERNESS & ENVIRONMENTAL MEDICINE Quigley, I., Zafren, K. 2016; 27 (2): 256-258

  Abstract

  High altitude cerebral edema (HACE) is a life-threatening condition that can affect people who ascend to altitudes above 2500 m. Altered mental status and the presence of ataxia distinguishes HACE from acute mountain sickness (AMS). We describe a patient with subtle cognitive dysfunction, likely due to HACE that had not fully resolved. When he initially presented, the patient appeared to have normal mental status and was not ataxic. The diagnosis of HACE was missed initially but was made when further history became available. Cognitive dysfunction was then diagnosed based on abnormal performance of a clock drawing test. A formal mental status examination, using a clock drawing test, may be helpful in assessing whether a patient at high altitude with apparently normal mental status and with normal gait has HACE.

  View details for PubMedID 26874815

• The Great Earthquake in Nepal-A Personal View WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K. 2016; 27 (1): 171–75

  View details for PubMedID 26596240

• A Pain in the Neck. Clay shoveler's fracture due to cervical spine trauma. Wilderness & environmental medicine Koirala, P., Wolpin, S., Phuyal, P., Basnyat, B., Zafren, K. 2015; 26 (3): 430-432

  View details for DOI 10.1016/j.wem.2015.03.003

  View details for PubMedID 25858233

• Hypothermia Evidence, Afterdrop, and Guidelines WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K., Giesbrecht, G. G., Danzl, D. F., Bragger, H., Sagalyn, E. B., Walpoth, B., Weiss, E. A., Auerbach, P. S., McIntosh, S. E., Nemethy, M., McDevitt, M., Dow, J., Schoene, R. B., Rodway, G. W., Hackett, P. H., Bennett, B. L., Grissom, C. K. 2015; 26 (3): 439–41

  View details for PubMedID 25840910

• An Itchy Situation WILDERNESS & ENVIRONMENTAL MEDICINE Phuyal, P., Koirala, P., Basnyat, B., Zafren, K. 2015; 26 (1): 89–90

  View details for PubMedID 25443760

• Cold Injuries IOC MANUAL OF EMERGENCY SPORTS MEDICINE Zafren, K., Giesbrecht, G., McDonagh, D., McDonagh, D., Zideman, D. 2015: 220–27

  View details for Web of Science ID 000457080500026

• Wilderness Medical Society practice guidelines for the prevention and treatment of acute altitude illness: 2014 update. Wilderness & environmental medicine Luks, A. M., McIntosh, S. E., Grissom, C. K., Auerbach, P. S., Rodway, G. W., Schoene, R. B., Zafren, K., Hackett, P. H. 2014; 25 (4): S4-14

  Abstract

  To provide guidance to clinicians about best practices, the Wilderness Medical Society convened an expert panel to develop evidence-based guidelines for prevention and treatment of acute mountain sickness, high altitude cerebral edema, and high altitude pulmonary edema. These guidelines present the main prophylactic and therapeutic modalities for each disorder and provide recommendations about their role in disease management. Recommendations are graded based on the quality of supporting evidence and balance between the benefits and risks/burdens according to criteria put forth by the American College of Chest Physicians. The guidelines also provide suggested approaches to prevention and management of each disorder that incorporate these recommendations. This is an updated version of the original WMS Consensus Guidelines for the Prevention and Treatment of Acute Altitude Illness published in Wilderness & Environmental Medicine 2010;21(2):146-155.

  View details for DOI 10.1016/j.wem.2014.06.017

  View details for PubMedID 25498261

• Wilderness Medical Society Practice Guidelines for the Out-of-Hospital Evaluation and Treatment of Accidental Hypothermia: 2014 Update. Wilderness & environmental medicine Zafren, K., Giesbrecht, G. G., Danzl, D. F., Brugger, H., Sagalyn, E. B., Walpoth, B., Weiss, E. A., Auerbach, P. S., McIntosh, S. E., Némethy, M., McDevitt, M., Dow, J., Schoene, R. B., Rodway, G. W., Hackett, P. H., Bennett, B. L., Grissom, C. K. 2014; 25 (4): S66-85

  View details for DOI 10.1016/j.wem.2014.10.010

  View details for PubMedID 25498264

• Wilderness medical society practice guidelines for the prevention and treatment of acute altitude illness: 2014 update. Wilderness & environmental medicine Luks, A. M., McIntosh, S. E., Grissom, C. K., Auerbach, P. S., Rodway, G. W., Schoene, R. B., Zafren, K., Hackett, P. H. 2014; 25 (4): S4-S14

  Abstract

  To provide guidance to clinicians about best practices, the Wilderness Medical Society convened an expert panel to develop evidence-based guidelines for prevention and treatment of acute mountain sickness, high altitude cerebral edema, and high altitude pulmonary edema. These guidelines present the main prophylactic and therapeutic modalities for each disorder and provide recommendations about their role in disease management. Recommendations are graded based on the quality of supporting evidence and balance between the benefits and risks/burdens according to criteria put forth by the American College of Chest Physicians. The guidelines also provide suggested approaches to prevention and management of each disorder that incorporate these recommendations. This is an updated version of the original WMS Consensus Guidelines for the Prevention and Treatment of Acute Altitude Illness published in Wilderness & Environmental Medicine 2010;21(2):146-155.

  View details for DOI 10.1016/j.wem.2014.06.017

  View details for PubMedID 25498261

• Wilderness Medical Society practice guidelines for basic wound management in the austere environment: 2014 update. Wilderness & environmental medicine Quinn, R. H., Wedmore, I., Johnson, E. L., Islas, A. A., Anglim, A., Zafren, K., Bitter, C., Mazzorana, V. 2014; 25 (4): S118-33

  Abstract

  In an effort to produce best-practice guidelines for wound management in the austere environment, the Wilderness Medical Society convened an expert panel charged with the development of evidence-based guidelines for the management of wounds sustained in an austere (dangerous or compromised) environment. Recommendations are made about several parameters related to wound management. These recommendations are graded based on the quality of supporting evidence and the balance between the benefits and risks or burdens for each parameter according to the methodology stipulated by the American College of Chest Physicians. This is an updated version of the original guidelines published in Wilderness & Environmental Medicine 2014;25(3):295-310.

  View details for DOI 10.1016/j.wem.2014.08.015

  View details for PubMedID 25498257

• Wilderness Medical Society Practice Guidelines for Basic Wound Management in the Austere Environment WILDERNESS & ENVIRONMENTAL MEDICINE Quinn, R. H., Wedmore, I., Johnson, E., Islas, A., Anglim, A., Zafren, K., Bitter, C., Mazzorana, V. 2014; 25 (3): 295-310

  Abstract

  In an effort to produce best-practice guidelines for wound management in the austere environment, the Wilderness Medical Society convened an expert panel charged with the development of evidence-based guidelines for the management of wounds sustained in an austere (dangerous or compromised) environment. Recommendations are made about several parameters related to wound management. These recommendations are graded based on the quality of supporting evidence and the balance between the benefits and risks or burdens for each parameter according to the methodology stipulated by the American College of Chest Physicians.

  View details for PubMedID 24931588

• Spine Protection in the Austere Environment WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K., Smith, W. R., Johnson, D. E., Kovacs, T. 2014; 25 (3): 364–66

  View details for PubMedID 24931589

• Wilderness Medical Society Practice Guidelines for the Prevention and Treatment of Lightning Injuries: 2014 Update WILDERNESS & ENVIRONMENTAL MEDICINE Davis, C., Engeln, A., Johnson, E. L., McIntosh, S. E., Zafren, K., Islas, A. A., McStay, C., Smith, W. R., Cushing, T. 2014; 25 (4): S86-S95

  Abstract

  To provide guidance to clinicians about best practices, the Wilderness Medical Society (WMS) convened an expert panel to develop evidence-based guidelines for the treatment and prevention of lightning injuries. These guidelines include a review of the epidemiology of lightning and recommendations for the prevention of lightning strikes, along with treatment recommendations organized by organ system. Recommendations are graded on the basis of the quality of supporting evidence according to criteria put forth by the American College of Chest Physicians. This is an updated version of the original WMS Practice Guidelines for Prevention and Treatment of Lightning Injuries published in Wilderness & Environmental Medicine 2012;23(3):260-269.

  View details for DOI 10.1016/j.wem.2014.05.004

  View details for PubMedID 25498265

• Prevention of high altitude illness TRAVEL MEDICINE AND INFECTIOUS DISEASE Zafren, K. 2014; 12 (1): 29–39

  Abstract

  High altitude illness - Acute Mountain Sickness (AMS), High Altitude Cerebral Edema (HACE) and High Altitude Pulmonary Edema (HAPE) - can be prevented or limited in severity by gradual ascent and by pharmacologic methods. The decision whether to use pharmacologic prophylaxis depends on the ascent rate and an individual's previous history of altitude illness. This review discusses risk stratification to determine whether to use pharmacologic prophylaxis and recommends specific drugs, especially acetazolamide, dexamethasone and nifedipine. This review also evaluates non-recommended drugs. In addition, this review suggests non-pharmacologic methods of decreasing the risk of severe altitude illness. There are also brief sections on how to decrease sleep disturbance at high altitude, travel to high altitude for patients with pre-existing illness and advice for travelers ascending to high altitude.

  View details for PubMedID 24393671

• Wilderness Medical Society Practice Guidelines for Basic Wound Management in the Austere Environment: 2014 Update WILDERNESS & ENVIRONMENTAL MEDICINE Quinn, R. H., Wedmore, I., Johnson, E. L., Islas, A. A., Anglim, A., Zafren, K., Bitter, C., Mazzorana, V. 2014; 25 (4): S118-S133

  Abstract

  In an effort to produce best-practice guidelines for wound management in the austere environment, the Wilderness Medical Society convened an expert panel charged with the development of evidence-based guidelines for the management of wounds sustained in an austere (dangerous or compromised) environment. Recommendations are made about several parameters related to wound management. These recommendations are graded based on the quality of supporting evidence and the balance between the benefits and risks or burdens for each parameter according to the methodology stipulated by the American College of Chest Physicians. This is an updated version of the original guidelines published in Wilderness & Environmental Medicine 2014;25(3):295-310.

  View details for DOI 10.1016/j.wem.2014.08.015

  View details for Web of Science ID 000346949400012

  View details for PubMedID 25498257

• Wilderness Medical Society Practice Guidelines for the Out-of-Hospital Evaluation and Treatment of Accidental Hypothermia WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K., Giesbrecht, G. G., Danzl, D. F., Brugger, H., Sagalyn, E. B., Walpoth, B., Weiss, E. A., Auerbach, P. S., McIntosh, S. E., Nemethy, M., McDevitt, M., Dow, J., Schoene, R. B., Rodway, G. W., Hackett, P. H., Bennett, B. L., Grissom, C. K. 2014; 25 (4): 425-445

  Abstract

  To provide guidance to clinicians, the Wilderness Medical Society (WMS) convened an expert panel to develop evidence-based guidelines for the out-of-hospital evaluation and treatment of victims of accidental hypothermia. The guidelines present the main diagnostic and therapeutic modalities and provide recommendations for the management of hypothermic patients. The panel graded the recommendations based on the quality of supporting evidence and the balance between benefits and risks/burdens according the criteria published by the American College of Chest Physicians. The guidelines also provide suggested general approaches to the evaluation and treatment of accidental hypothermia that incorporate specific recommendations.

  View details for PubMedID 25443771

• Resuscitation of avalanche victims: Evidence-based guidelines of the international commission for mountain emergency medicine (ICAR MEDCOM) Intended for physicians and other advanced life support personnel RESUSCITATION Brugger, H., Durrer, B., Elsensohn, F., Paal, P., Strapazzon, G., Winterberger, E., Zafren, K., Boyd, J. 2013; 84 (5): 539-546

  Abstract

  In North America and Europe ∼150 persons are killed by avalanches every year.The International Commission for Mountain Emergency Medicine (ICAR MEDCOM) systematically developed evidence-based guidelines and an algorithm for the management of avalanche victims using a worksheet of 27 Population Intervention Comparator Outcome questions. Classification of recommendations and level of evidence are ranked using the American Heart Association system.If lethal injuries are excluded and the body is not frozen, the rescue strategy is governed by the duration of snow burial and, if not available, by the victim's core-temperature. If burial time ≤35 min (or core-temperature ≥32 °C) rapid extrication and standard ALS is important. If burial time >35 min and core-temperature <32 °C, treatment of hypothermia including gentle extrication, full body insulation, ECG and core-temperature monitoring is recommended, and advanced airway management if appropriate. Unresponsive patients presenting with vital signs should be transported to a hospital capable of active external and minimally invasive rewarming such as forced air rewarming. Patients with cardiac instability or in cardiac arrest (with a patent airway) should be transported to a hospital for extracorporeal membrane oxygenation or cardiopulmonary bypass rewarming. Patients in cardiac arrest should receive uninterrupted CPR; with asystole, CPR may be terminated (or withheld) if a patient is lethally injured or completely frozen, the airway is blocked and duration of burial >35 min, serum potassium >12 mmol L(-1), risk to the rescuers is unacceptably high or a valid do-not-resuscitate order exists. Management should include spinal precautions and other trauma care as indicated.

  View details for DOI 10.1016/j.resuscitation.2012.10.020

  View details for Web of Science ID 000320996600008

  View details for PubMedID 23123559

• "Performance enhancing" drugs at high altitude. Wilderness & environmental medicine Zafren, K. n., Berghold, F. n., Hillebrandt, D. n. 2013; 24 (2): 173–74

  View details for DOI 10.1016/j.wem.2012.11.012

  View details for PubMedID 23434166

• Prophylaxis for Acute Mountain Sickness ANNALS OF EMERGENCY MEDICINE Zafen, K. 2012; 60 (5): 671-672

  View details for DOI 10.1016/j.annemergmed.2012.05.017

  View details for Web of Science ID 000310928800026

  View details for PubMedID 23089097

• Wilderness Medical Society Practice Guidelines for the Prevention and Treatment of Lightning Injuries WILDERNESS & ENVIRONMENTAL MEDICINE Davis, C., Engeln, A., Johnson, E., McIntosh, S. E., Zafren, K., Islas, A. A., McStay, C., Smith, W. '., Cushing, T. 2012; 23 (3): 260-269

  Abstract

  To provide guidance to clinicians about best practices, the Wilderness Medical Society convened an expert panel to develop evidence-based guidelines for the treatment and prevention of lightning injuries. These guidelines include a review of the epidemiology of lightning strikes and recommendations for the prevention of lightning strikes, along with treatment recommendations organized by organ system. Recommendations are graded based on the quality of supporting evidence according to criteria put forth by the American College of Chest Physicians.

  View details for Web of Science ID 000308284600013

  View details for PubMedID 22854068

• Public Access Defibrillation ANNALS OF EMERGENCY MEDICINE Zafren, K. 2012; 59 (6): 558-558

  View details for DOI 10.1016/j.annemergmed.2011.11.044

  View details for Web of Science ID 000305302300026

  View details for PubMedID 22626023

• Does Ibuprofen Prevent Acute Mountain Sickness? WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K. 2012; 23 (4): 297-299

  View details for Web of Science ID 000311914700001

  View details for PubMedID 23158203

• Prediction of Acute Mountain Sickness by Pulse Oximetry: What Are the Right Questions? WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K. 2012; 23 (4): 377-378

  View details for Web of Science ID 000311914700017

  View details for PubMedID 22981487

• Accident on Mt Kenya WILDERNESS & ENVIRONMENTAL MEDICINE Oelz, O., Zafren, K. 2011; 22 (1): 87–90

  View details for DOI 10.1016/j.wem.2010.09.009

  View details for Web of Science ID 000288342900015

  View details for PubMedID 21377126

• In Response to "Wilderness Medical Society Practice Guidelines for the Prevention and Treatment of Frostbite" WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K. 2011; 22 (4): 364-365

  View details for Web of Science ID 000297966300014

  View details for PubMedID 21982756

• In Response to Bradford Washburn's 1962 NEJM Article "Frostbite: What It Is-How To Prevent It-Emergency Treatment"-Historical Background and Commentary WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K. 2011; 22 (4): 366-368

  View details for Web of Science ID 000297966300016

  View details for PubMedID 22000546

• Avalanche Triage: Are Two Birds in the Bush Better Than One in the Hand? WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K. 2010; 21 (3): 273-274

  View details for Web of Science ID 000282163300016

  View details for PubMedID 20832710

• Prospective, Double-Blind, Randomized, Placebo-Controlled Comparison of Acetazolamide Versus Ibuprofen for Prophylaxis Against High Altitude Headache: The Headache Evaluation at Altitude Trial (HEAT) WILDERNESS & ENVIRONMENTAL MEDICINE Gertsch, J. H., Lipman, G. S., Holck, P. S., Merritt, A., Mulcahy, A., Fisher, R. S., Basnyat, B., Allison, E., Hanzelka, K., Hazan, A., Meyers, Z., Odegaard, J., Pook, B., Thompson, M., Slomovic, B., Wahlberg, H., Wilshaw, V., Weiss, E. A., Zafren, K. 2010; 21 (3): 236-243

  Abstract

  High altitude headache (HAH) is the most common neurological complaint at altitude and the defining component of acute mountain sickness (AMS). However, there is a paucity of literature concerning its prevention. Toward this end, we initiated a prospective, double-blind, randomized, placebo-controlled trial in the Nepal Himalaya designed to compare the effectiveness of ibuprofen and acetazolamide for the prevention of HAH.Three hundred forty-three healthy western trekkers were recruited at altitudes of 4280 m and 4358 m and assigned to receive ibuprofen 600 mg, acetazolamide 85 mg, or placebo 3 times daily before continued ascent to 4928 m. Outcome measures included headache incidence and severity, AMS incidence and severity on the Lake Louise AMS Questionnaire (LLQ), and visual analog scale (VAS).Two hundred sixty-five of 343 subjects completed the trial. HAH incidence was similar when treated with acetazolamide (27.1%) or ibuprofen (27.5%; P = .95), and both agents were significantly more effective than placebo (45.3%; P = .01). AMS incidence was similar when treated with acetazolamide (18.8%) or ibuprofen (13.7%; P = .34), and both agents were significantly more effective than placebo (28.6%; P = .03). In fully compliant participants, moderate or severe headache incidence was similar when treated with acetazolamide (3.8%) or ibuprofen (4.7%; P = .79), and both agents were significantly more effective than placebo (13.5%; P = .03).Ibuprofen and acetazolamide were similarly effective in preventing HAH. Ibuprofen was similar to acetazolamide in preventing symptoms of AMS, an interesting finding that implies a potentially new approach to prevention of cerebral forms of acute altitude illness.

  View details for Web of Science ID 000282163300007

  View details for PubMedID 20832701

• Wilderness Medical Society Consensus Guidelines for the Prevention and Treatment of Acute Altitude Illness WILDERNESS & ENVIRONMENTAL MEDICINE Luks, A. M., McIntosh, S. E., Grissom, C. K., Auerbach, P. S., Rodway, G. W., Schoene, R. B., Zafren, K., Hackett, P. H. 2010; 21 (2): 146-155

  Abstract

  To provide guidance to clinicians about best practices, the Wilderness Medical Society (WMS) convened an expert panel to develop evidence-based guidelines for the prevention and treatment of acute mountain sickness (AMS), high altitude cerebral edema (HACE), and high altitude pulmonary edema (HAPE). These guidelines present the main prophylactic and therapeutic modalities for each disorder and provide recommendations for their roles in disease management. Recommendations are graded based on the quality of supporting evidence and balance between the benefits and risks/burdens according to criteria put forth by the American College of Chest Physicians. The guidelines also provide suggested approaches to the prevention and management of each disorder that incorporate these recommendations.

  View details for Web of Science ID 000279235900013

  View details for PubMedID 20591379

• Wilderness Medical Society Consensus Guidelines for the Prevention and Treatment of Acute Altitude Illness-A View From the Other Side of the Atlantic Reply WILDERNESS & ENVIRONMENTAL MEDICINE Luks, A. M., McIntosh, S. E., Grissom, C. K., Auerbach, P. S., Rodway, G. W., Schoene, R. B., Zafren, K., Hackett, P. 2010; 21 (4): 384-385

  View details for Web of Science ID 000285703700021

• Clinical Images WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K., Basnyat, B., Basnyat, G. 2009; 20 (1): 81-82

  View details for Web of Science ID 000264280300015

  View details for PubMedID 19364167

• Fluid management in traumatic shock: a practical approach for mountain rescue. Official recommendations of the International Commission for Mountain Emergency Medicine (ICAR MEDCOM). High altitude medicine & biology Sumann, G., Paal, P., Mair, P., Ellerton, J., Dahlberg, T., Zen-Ruffinen, G., Zafren, K., Brugger, H. 2009; 10 (1): 71-75

  Abstract

  Sumann, Günther, Peter Paal, Peter Mair, John Ellerton, Tore Dahlberg, Gregoire Zen-Ruffinen, Ken Zafren, and Hermann Brugger. Fluid management in traumatic shock: a practical approach for mountain rescue. High Alt. Med. Biol. 10:71-75, 2009.-The management of severe injuries leading to traumatic shock in mountains and remote areas is a great challenge for emergency physicians and rescuers. Traumatic brain injury may further aggravate outcome. A mountain rescue mission may face severe limitations from the terrain and required rescue technique. The mission may be characterized by a prolonged prehospital care time, where urban traumatic shock protocols may not apply. Yet optimal treatment is of utmost importance. The aim of this study is to establish scientifically supported recommendations for fluid management that are feasible for the physician or paramedic attending such an emergency. A nonsystematic literature search was performed; the results and recommendations were discussed among the authors and accepted by the International Commission for Mountain Emergency Medicine (ICAR MEDCOM). Diagnostic and therapeutic strategies are discussed, as well as limitations on therapy in mountain rescue. An algorithm for fluid resuscitation, derived from the recommendations, is presented in Fig. 1. Focused on the key criterion of traumatic brain injury, different levels of blood pressure are presented as a goal of therapy, and the practical means for achieving these are given.

  View details for DOI 10.1089/ham.2008.1067

  View details for PubMedID 19278354

• Fluid Management in Traumatic Shock: A Practical Approach for Mountain Rescue HIGH ALTITUDE MEDICINE & BIOLOGY Sumann, G., Paal, P., Mair, P., Ellerton, J., Dahlberg, T., Zen-Ruffinen, G., Zafren, K., Brugger, H. 2009; 10 (1): 71-75

  Abstract

  Sumann, Günther, Peter Paal, Peter Mair, John Ellerton, Tore Dahlberg, Gregoire Zen-Ruffinen, Ken Zafren, and Hermann Brugger. Fluid management in traumatic shock: a practical approach for mountain rescue. High Alt. Med. Biol. 10:71-75, 2009.-The management of severe injuries leading to traumatic shock in mountains and remote areas is a great challenge for emergency physicians and rescuers. Traumatic brain injury may further aggravate outcome. A mountain rescue mission may face severe limitations from the terrain and required rescue technique. The mission may be characterized by a prolonged prehospital care time, where urban traumatic shock protocols may not apply. Yet optimal treatment is of utmost importance. The aim of this study is to establish scientifically supported recommendations for fluid management that are feasible for the physician or paramedic attending such an emergency. A nonsystematic literature search was performed; the results and recommendations were discussed among the authors and accepted by the International Commission for Mountain Emergency Medicine (ICAR MEDCOM). Diagnostic and therapeutic strategies are discussed, as well as limitations on therapy in mountain rescue. An algorithm for fluid resuscitation, derived from the recommendations, is presented in Fig. 1. Focused on the key criterion of traumatic brain injury, different levels of blood pressure are presented as a goal of therapy, and the practical means for achieving these are given.

  View details for DOI 10.1089/ham.2008.1067

  View details for Web of Science ID 000264087400008

• The Most Dangerous Catch: Fisherman Caught by Halibut Hook WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K. 2009; 20 (4): 375-377

  View details for Web of Science ID 000273503700013

  View details for PubMedID 20030448

• The use of extrication devices in crevasse accidents: official statement of the International Commission for Mountain Emergency Medicine and the Terrestrial Rescue Commission of the International Commission for Alpine Rescue intended for physicians, paramedics, and mountain rescuers WILDERNESS & ENVIRONMENTAL MEDICINE Winterberger, E., Jacomet, H., Zafren, K., Ruffinen, G. Z., Jelk, B. 2008; 19 (2): 108-110

  Abstract

  Injured patients in crevasses who are suspected of having sustained spinal injuries should ideally be extricated after being immobilized in a horizontal position on a stretcher and having a cervical collar applied. Sometimes, however, horizontal stabilization is not possible, because the crevasse is too narrow, and the patient needs to be stabilized in a vertical position. In such cases an extrication device can be a useful adjunct. The Kendrick Extrication Device stabilizes the position of the body and maintains firm support of the head, neck, and torso. Therefore, the International Commission for Mountain Emergency Medicine supports the use of this device in narrow crevasses, if horizontal evacuation is not possible.

  View details for Web of Science ID 000256509600005

  View details for PubMedID 18513106

• When searches become futile WILDERNESS & ENVIRONMENTAL MEDICINE Fortini, A., Zafren, K., Sharp, F., Shimanski, C. 2008; 19 (1): 73-73

  View details for Web of Science ID 000254367000015

  View details for PubMedID 18333661

• A reference correction. Wilderness & environmental medicine Zafren, K. 2007; 18 (4): 323-?

  View details for PubMedID 18076299

• Management of blunt trauma victims with significant hemoperitoneum with normal examination AMERICAN JOURNAL OF EMERGENCY MEDICINE Zafren, K. 2003; 21 (6): 513-513

  View details for DOI 10.1016/S0735-6757(03)00172-4

  View details for Web of Science ID 000186208300023

  View details for PubMedID 14574671

• Clinical images. Wound care in the wilderness. Wilderness & environmental medicine Zafren, K. 2001; 12 (3): 201-203

  View details for PubMedID 11562020

• Effect of insurance on admission for head injury AMERICAN JOURNAL OF EMERGENCY MEDICINE Zafren, K. 2001; 19 (5): 460-460

  View details for Web of Science ID 000170970400019

  View details for PubMedID 11555813

• Warnings in the wilderness WILDERNESS & ENVIRONMENTAL MEDICINE Anonymous 2001; 12 (2): 129-133

  View details for Web of Science ID 000169377300010

  View details for PubMedID 11434489

• Poison oak dermatitis. Wilderness & environmental medicine Zafren, K. 2001; 12 (1): 39-40

  View details for PubMedID 11294555

• How useful is on-mountain sonography? WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K. 2001; 12 (4): 230-231

  View details for Web of Science ID 000172919300002

  View details for PubMedID 11769916

• Unusual presentation of a fracture and possible early compartment syndrome. Wilderness & environmental medicine Zafren, K. 2000; 11 (3): 199-200

  View details for PubMedID 11055568

• Clinical images WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K. 2000; 11 (4): 269-271

  View details for Web of Science ID 000166445800007

  View details for PubMedID 11199532

• Images - Erythema nodosum WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, Z., Kercher, E. 1999; 10 (3): 171-173

  View details for Web of Science ID 000083483600008

  View details for PubMedID 10560312

• Images - Answer WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K. 1999; 10 (2): 115-116

  View details for Web of Science ID 000081796100010

  View details for PubMedID 10442160

• Presentation of the case. Lighting injuries. Wilderness & environmental medicine Zafren, K. 1999; 10 (4): 253-255

  View details for PubMedID 10628287

• Tragedy on Ptarmigan Peak WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K. 1998; 9 (3): 188-190

  View details for Web of Science ID 000080104900008

  View details for PubMedID 11990189

• Migratory pain in appendicitis AMERICAN JOURNAL OF EMERGENCY MEDICINE Zafren, K. 1998; 16 (4): 437-438

  View details for Web of Science ID 000074870100035

  View details for PubMedID 9672474

• Telemedicine revisited ANNALS OF EMERGENCY MEDICINE Zafren, K. 1998; 31 (6): 790-790

  View details for Web of Science ID 000073986100022

  View details for PubMedID 9624327

• Brown recluse spider bite (necrotic arachnidism) WILDERNESS & ENVIRONMENTAL MEDICINE Zafren, K. 1998; 9 (4): 211-212

  View details for Web of Science ID 000079405000003

  View details for PubMedID 11990193

• Re: Prevention and Management of Cardiovascular Events during Travel. Journal of travel medicine Zafren, K. n. 1997; 4 (3): 152

  View details for PubMedID 9815504

• Outcome assessments and air ambulance services LANCET Zafren, K. 1996; 347 (9018): 1843-1843

  View details for Web of Science ID A1996UU46900072

  View details for PubMedID 8667965

• Warning! Long commute. Science Zafren, K. 1996; 272 (5269): 1726a-?

  View details for PubMedID 17831839

• Warning! Long commute SCIENCE Zafren, K. 1996; 272 (5269): 1726

  View details for Web of Science ID A1996UT11000008

• ALTERNATIVE TRAINING IN EMERGENCY-MEDICINE AMERICAN JOURNAL OF EMERGENCY MEDICINE Zafren, K. 1993; 11 (1): 97-98

  View details for Web of Science ID A1993KL86500028

  View details for PubMedID 8447885

• BASE DEFICIT AS A DIAGNOSTIC-TEST FOR ABDOMINAL INJURY ANNALS OF EMERGENCY MEDICINE Zafren, K., Purcell, T. 1992; 21 (11): 1406-1406

  View details for Web of Science ID A1992JU81200023

  View details for PubMedID 1416343

• OPEN AND CLOSED PERITONEAL-LAVAGE ANNALS OF EMERGENCY MEDICINE Zafren, K., Purcell, T. 1992; 21 (10): 1298-1298

  View details for Web of Science ID A1992JR19600028

  View details for PubMedID 1416319