- Pediatric Emergency Medicine
Clinical Professor, Emergency Medicine
Clinical Professor, Pediatrics
Director, Pediatric Emergency Department, Stanford University, LPCH (2004 - Present)
Residency: Loma Linda University - School of Medicine (1996) CA
Internship: Loma Linda University - School of Medicine (1994) CA
Residency: UCI Medical Center (1993) CA
Internship: UCI Medical Center (1991) CA
Board Certification: American Board of Emergency Medicine, Emergency Medicine (1997)
Board Certification: American Board of Pediatrics, Pediatrics (1994)
Board Certification: American Board of Emergency Medicine, Pediatric Emergency Medicine (1999)
Medical Education: Ludwig Maximillians University (1986) Germany
FACEP, Loma Linda University, Emergency Medicine (1996)
FAAP, University of California, Irvine, Residency in Pediatrics (1993)
MD, Ludwig-Maximilian-Universität, Medical School, Munich (1986)
Current Research and Scholarly Interests
Pediatric Pain Management and Sedation
Emergency department implementation of abbreviated magnetic resonance imaging for pediatric traumatic brain injury.
Journal of the American College of Emergency Physicians open
2020; 1 (5): 994–99
Pediatric head injury is a common presenting complaint in the emergency department (ED), often requiring neuroimaging or ED observation for diagnosis. However, the traditional diagnostic neuroimaging modality, head computed tomography (CT), is associated with radiation exposure while prolonged ED observation impacts patient flow and resource utilization. Recent scientific literature supports abbreviated, or focused and shorter, brain magnetic resonance imaging (MRI) as a feasible and accurate diagnostic alternative to CT for traumatic brain injury. However, this is a relatively new application and its use is not widespread. The aims of this review are to describe the science and applications of abbreviated brain MRI and report a model protocol's development and ED implementation in the evaluation of children with head injury for replication in other institutions.
View details for DOI 10.1002/emp2.12055
View details for PubMedID 33145550
View details for PubMedCentralID PMC7593499
- R-SCAN: Imaging for Pediatric Simple Febrile Seizures. Journal of the American College of Radiology 2017
Prehospital Use of Magnesium Sulfate as Neuroprotection in Acute Stroke
NEW ENGLAND JOURNAL OF MEDICINE
2015; 372 (6): 528–36
Magnesium sulfate is neuroprotective in preclinical models of stroke and has shown signals of potential efficacy with an acceptable safety profile when delivered early after stroke onset in humans. Delayed initiation of neuroprotective agents has hindered earlier phase 3 trials of neuroprotective agents.We randomly assigned patients with suspected stroke to receive either intravenous magnesium sulfate or placebo, beginning within 2 hours after symptom onset. A loading dose was initiated by paramedics before the patient arrived at the hospital, and a 24-hour maintenance infusion was started on the patient's arrival at the hospital. The primary outcome was the degree of disability at 90 days, as measured by scores on the modified Rankin scale (range, 0 to 6, with higher scores indicating greater disability).Among the 1700 enrolled patients (857 in the magnesium group and 843 in the placebo group), the mean (±SD) age was 69±13 years, 42.6% were women, and the mean pretreatment score on the Los Angeles Motor Scale of stroke severity (range, 0 to 10, with higher scores indicating greater motor deficits) was 3.7±1.3. The final diagnosis of the qualifying event was cerebral ischemia in 73.3% of patients, intracranial hemorrhage in 22.8%, and a stroke-mimicking condition in 3.9%. The median interval between the time the patient was last known to be free of stroke symptoms and the start of the study-drug infusion was 45 minutes (interquartile range, 35 to 62), and 74.3% of patients received the study-drug infusion within the first hour after symptom onset. There was no significant shift in the distribution of 90-day disability outcomes on the global modified Rankin scale between patients in the magnesium group and those in the placebo group (P=0.28 by the Cochran-Mantel-Haenszel test); mean scores at 90 days did not differ between the magnesium group and the placebo group (2.7 in each group, P=1.00). No significant between-group differences were noted with respect to mortality (15.4% in the magnesium group and 15.5% in the placebo group, P=0.95) or all serious adverse events.Prehospital initiation of magnesium sulfate therapy was safe and allowed the start of therapy within 2 hours after the onset of stroke symptoms, but it did not improve disability outcomes at 90 days. (Funded by the National Institute of Neurological Disorders and Stroke; FAST-MAG ClinicalTrials.gov number, NCT00059332.).
View details for DOI 10.1056/NEJMoa1408827
View details for Web of Science ID 000349143600007
View details for PubMedID 25651247
View details for PubMedCentralID PMC4920545
Tension pneumoperitoneum after intussusception pneumoreduction
PEDIATRIC EMERGENCY CARE
2007; 23 (8): 563-564
Intussusception is the most common cause of intestinal obstruction in infancy. Presentation, diagnostic workup, and treatment are well understood and noncontroversial. Complications of bowel perforation are also well documented. We discuss a case of tension pneumoperitoneum after intestinal perforation during intussusception pneumoreduction in a 5-month-old child and review initial presentation, diagnosis, and management of this disease. It is important to recognize this rare complication of pneumoreduction and promptly treat the ensuing tension pneumoperitoneum.
View details for Web of Science ID 000248777100009
View details for PubMedID 17726417
Pulse oximetry in discharge decision-making: a survey of emergency physicians.
2002; 4 (6): 388-393
Our primary objective was to describe the pulse oximetry discharge thresholds used by general and pediatric emergency physicians for well-appearing children with bronchiolitis and pneumonia, and to assess the related practice variability.This mail-in survey was conducted in August and September 2001 and included the 281 active members of the Pediatric Emergency Medicine Section of the American College of Emergency Physicians. The survey consisted of 2 case scenarios of previously healthy, well-appearing children: a 2-year-old with pneumonia and a 10-month-old with bronchiolitis. Respondents were asked about their years of experience, teaching load, percentage of children in their practice, whether they currently have a written departmental guideline at their institution, and the lowest pulse oximetry reading that they would accept and still discharge the patient directly home.One hundred and eighty-two (65%) physicians answered the survey and met the inclusion criteria. The respondents' median oximetry value and interquartile range (IQR) for the pneumonia and bronchiolitis cases were 93% (92%-94%) and 94% (92%-94%) respectively. With the exception of the 3 physicians practising >1000 metres above sea level, the responses by subgroups were similar.There does not yet exist a safe, clinically validated pulse oximetry discharge threshold. Emergency physicians from this study sample have a modest degree of practice variability in a self-reported pulse oximetry discharge threshold. Emergency physicians may use this data to compare their own practice with that reported by this group.
View details for PubMedID 17637155
Does adjunctive midazolam reduce recovery agitation after ketamine sedation for pediatric procedures? A randomized, double-blind, placebo-controlled trial
ANNALS OF EMERGENCY MEDICINE
2000; 35 (3): 229-238
Despite widespread use of adjunctive benzodiazepines during ketamine sedation, their efficacy in reducing recovery agitation in children has never been studied. We wished to characterize the nature and severity of recovery agitation after ketamine sedation in children treated in the emergency department and to determine whether the addition of adjunctive midazolam reduces the magnitude of such recovery agitation.The study was a randomized, double-blind, clinical trial of adjunctive midazolam versus placebo during ketamine sedation. We enrolled 104 children aged 12 months to 15 years (median age, 6 years) at a combined university medical center and children's hospital. Subjects received either intravenous midazolam (0.05 mg/kg up to 2 mg) or placebo after intravenous administration of a ketamine loading dose (1.5 mg/kg). Treating physicians and nurses independently noted the presence of crying, hallucinations, and nightmares during recovery and graded recovery agitation by using a 100-mm visual analog scale. Preprocedure agitation and external stimulation during recovery were also graded. The time from ketamine injection until each subject met the recovery criteria was recorded.Fifty-three subjects received midazolam, and 51 received placebo. Potentially confounding variables were similar between the groups. Sedation efficacy, adverse effects, and recovery time were also similar between groups. Interobserver agreement between physician and nurse assessments was substantial. Median physician assessment of recovery agitation was 4 mm (interquartile range, 2 to 19) in the midazolam group and 5 mm (interquartile range, 3 to 14) in the placebo group (difference -1; 95% confidence interval -3 to 2; P =.705). Recovery agitation was moderately correlated with preprocedure agitation (rho=0.486) but not with external stimulation during recovery (rho=0.147).Recovery agitation is common but generally of very low magnitude after ketamine sedation in children in the ED. We observed a median physician rating of 5 mm on a 100-mm visual analog scale, a score that we believe to be clinically insignificant. The degree of recovery agitation after ketamine sedation is significantly related to the degree of preprocedure agitation. In this study, concurrent midazolam did not diminish such agitation and had no measurably beneficial effect. Use of adjunctive benzodiazepines in pediatric ketamine sedation appears unnecessary.
View details for Web of Science ID 000085774700004
View details for PubMedID 10692189
OCCURRENCE OF IGE-BEARING EPIDERMAL LANGERHANS CELLS IN ATOPIC ECZEMA - A STUDY OF THE TIME COURSE OF THE LESIONS AND WITH REGARD TO THE IGE SERUM LEVEL
JOURNAL OF INVESTIGATIVE DERMATOLOGY
1989; 93 (2): 215-219
Uninvolved and lesional skin of untreated and treated patients with atopic eczema has been investigated immunohistochemically to determine the conditions in which IgE-bearing CD1a+ Langerhans cells/indeterminate cells (LC/IC) occur in this disease. IgE-bearing epidermal dendritic cells were present in patients with elevated IgE serum level (greater than 300 UI/ml) and the staining pattern was stronger in lesional skin. On double immunostaining, a subpopulation of CD1a+ LC/IC was found not to bear IgE molecules as determined by the ratio IgE+/CD1a+ cells on serial sections as well. The ratio IgE+/CD1a+ cells decreased in patients who underwent a local therapy with glucocorticosteroids. These results suggest that the expression of IgE receptors and/or binding of IgE molecules on epidermal LC/IC in atopic eczema may be controlled by a complex network of mediators from the epidermis or the inflammatory infiltrate, or both, and that this phenomenon could be down regulated by glucocorticosteroids.
View details for Web of Science ID A1989AJ16000005
View details for PubMedID 2474029
KERATINOCYTES IN LESIONAL SKIN OF ATOPIC ECZEMA BEAR HLA-DR, CD1A AND IGE MOLECULES
CLINICAL AND EXPERIMENTAL DERMATOLOGY
1989; 14 (1): 35-39
Apparently normal, and lesional skin from patients with atopic eczema were investigated immunohistochemically with anti-HLA-DR, -CD1a and -IgE antisera. A CD1a+ intercellular pattern was observed in uninvolved skin in the majority of the patients whereas an HLA-DR+/CD1a+ network, mostly localized in basal and supra-basal areas, was shown in lesional skin of virtually all of them. Moreover, an HLA-DR+/CD1a+IgE+ intercellular pattern was observed in some of the patients only and was predominantly localized in those areas characterized by lymphocyte exocytosis, spongiosis or vesicle formation. Whether keratinocytes are able to synthesize CD1a antigen and Fc epsilon R or if these molecules are only produced and shed by CD1a+/IgE+ epidermal dendritic cells remains unclear.
View details for Web of Science ID A1989T083100008
View details for PubMedID 2478318