Clinical Focus


  • Emergency Medicine

Academic Appointments


Professional Education


  • Medical Education: Keck USC Medical Center Medical Staff Office (2011) CA
  • Residency, Alameda Health System - Highland Hospital, Emergency Medicine (2015)
  • Board Certification: American Board of Emergency Medicine, Emergency Medicine (2016)

All Publications


  • Low-Dose Ketamine Infusion for Emergency Department Patients with Severe Pain. Pain medicine (Malden, Mass.) Ahern, T. L., Herring, A. A., Miller, S., Frazee, B. W. 2015; 16 (7): 1402-9

    Abstract

    Use of low-dose ketamine infusions in the emergency department (ED) has not previously been described, despite routine use in perioperative and other settings. Our hypothesis was that a low-dose ketamine bolus followed by continuous infusion would 1) provide clinically significant and sustained pain relief; 2) be well tolerated; and 3) be feasible in the ED.We prospectively administered 15 mg intravenous ketamine followed immediately by continuous ketamine infusion at 20 mg/h for 1 hour. Optional morphine (4 mg) was offered at 20, 40, and 60 minutes. Pain intensity, vitals signs, level of sedation, and adverse reactions were assessed for 120 minutes.A total of 38 patients were included with a median initial numerical rating scale (NRS) pain score of 9. At 10 minutes, the median reduction in pain score was 4, with 7 patients reporting a score of 0. At 60 and 120 minutes, 25 and 26 patients, respectively, reported clinically significant pain reduction (decrease NRS score > 3). Heart rate, blood pressure, respiratory rate, and oxygen saturation remained stable. Mild or moderate side effects including dizziness, fatigue, and headache were common. Patient satisfaction was high; 85% reported they would have this medication again for similar pain.A low-dose ketamine infusion protocol provided significant pain relief with mostly mild side effects and no severe adverse events.

    View details for DOI 10.1111/pme.12705

    View details for PubMedID 25643741

  • Effective analgesia with low-dose ketamine and reduced dose hydromorphone in ED patients with severe pain. The American journal of emergency medicine Ahern, T. L., Herring, A. A., Stone, M. B., Frazee, B. W. 2013; 31 (5): 847-51

    Abstract

    We assessed the analgesic effect and feasibility of low-dose ketamine combined with a reduced dose of hydromorphone for emergency department (ED) patients with severe pain.This was a prospective observational study of adult patients with severe pain at an urban public hospital. We administered 0.5 mg of intravenous (IV) hydromorphone and 15 mg of IV ketamine, followed by optional 1 mg hydromorphone IV at 15 and 30 minutes. Pain intensity was assessed at 12 intervals over 120 minutes using a 10-point verbal numerical rating scale (NRS). Patients were monitored throughout for adverse events. Dissociative side effects were assessed using the side effects rating scale for dissociative anesthetics.Of 30 prospectively enrolled patients with severe pain (initial mean NRS, 9), 14 reported complete pain relief (NRS, 0) at 5 minutes; the mean reduction in NRS pain score was 6.0 (SD, 3.2). At 15 minutes, the mean reduction in NRS pain score was 5.0 (SD, 2.8). The summed pain intensity difference and percent summed pain intensity difference scores were 25 (95% confidence interval [CI], 21-30) and 58% (95% CI, 49-68) at 30 minutes and 41 (95% CI, 34-48) and 50% (95% CI, 42-58) at 60 minutes, respectively. Most patients (80%) reported only weak or modest side effects. Ninety percent of patients reported that they would have the medications again. No significant adverse events occurred.Low-dose ketamine combined with a reduced dose hydromorphone protocol produced rapid, profound pain relief without significant side effects in a diverse cohort of ED patients with acute pain.

    View details for DOI 10.1016/j.ajem.2013.02.008

    View details for PubMedID 23602757

  • Ultrasound-guided infraclavicular brachial plexus block for emergency management of a posterior elbow dislocation. The American journal of emergency medicine Heflin, T., Ahern, T., Herring, A. 2015; 33 (9): 1324.e1-4

    View details for DOI 10.1016/j.ajem.2015.06.019

    View details for PubMedID 26231527

  • A standardized Code Blue Team eliminates variable survival from in-hospital cardiac arrest. The Journal of emergency medicine Qureshi, S. A., Ahern, T., O'Shea, R., Hatch, L., Henderson, S. O. 2012; 42 (1): 74-8

    Abstract

    Recent studies suggest that time of day affects survival from in-hospital cardiac arrest. Lower survival rates are observed during nights and on weekends, except in areas with consistent physician care, such as the Emergency Department. Since 1997, our hospital has utilized a standard, hospital-wide "Code Blue Team" (CBT) to respond to cardiac arrests at any time. This team is always led by an emergency physician, and includes specially trained nurses.To assess if time of day or week affects survival from in-hospital cardiac arrest when a trained, consistent, emergency physician-led CBT is implemented.This is an analysis of prospectively collected data on initial survival rates (return of spontaneous circulation >20 min) of all cardiac arrests that were managed by the CBT from 2000 to 2008. Cardiac arrests were also subcategorized based on initial cardiac rhythm. Survival rates were compared according to time of day or week.A total of 1692 cardiac arrests were included. There was no significant difference in the overall rate of initial survival between day/evening vs. night hours (odds ratio [OR] 1.04, 95% confidence interval [CI] 0.83-1.29), or between weekday vs. weekend hours (OR 1.10, 95% CI 0.85-1.38). This held true for all cardiac rhythms.At our institution, there is no significant difference in survival from cardiac arrest when a standardized "Code Blue Team" is utilized, regardless of the time of day or week.

    View details for DOI 10.1016/j.jemermed.2010.10.023

    View details for PubMedID 21354760

  • Excited delirium. The western journal of emergency medicine Takeuchi, A., Ahern, T. L., Henderson, S. O. 2011; 12 (1): 77-83

    Abstract

    Excited (or agitated) delirium is characterized by agitation, aggression, acute distress and sudden death, often in the pre-hospital care setting. It is typically associated with the use of drugs that alter dopamine processing, hyperthermia, and, most notably, sometimes with death of the affected person in the custody of law enforcement. Subjects typically die from cardiopulmonary arrest, although the cause is debated. Unfortunately an adequate treatment plan has yet to be established, in part due to the fact that most patients die before hospital arrival. While there is still much to be discovered about the pathophysiology and treatment, it is hoped that this extensive review will provide both police and medical personnel with the information necessary to recognize and respond appropriately to excited delirium.

    View details for PubMedID 21691475

    View details for PubMedCentralID PMC3088378

  • Emergency department ultrasound by nurse practitioners. Journal of the American Academy of Nurse Practitioners Henderson, S. O., Ahern, T., Williams, D., Mailhot, T., Mandavia, D. 2010; 22 (7): 352-5

    Abstract

    Bedside ultrasound (u/s) examinations by emergency physicians (EPs) have been integrated into clinical emergency medicine (EM) training programs and the efficacy and success of an introductory u/s training course, based on established guidelines, has been previously described. We used this same course to teach EM nurse practitioners (NPs) bedside u/s and then assessed the adequacy of NP ultrasonography 1 year following the course.Five NPs were included in a standardized 16-h EM u/s training program. Subsequently, the NPs were asked to print consecutive u/s images representative of their clinical assessments. A single qualified EP reviewer assessed images for adequacy.Five NPs reported 229 u/s examinations, two of which were excluded as nondiagnostic over the 2-month study period. There were 32 inadequate images and 27 "positive" findings. All the positives were correct. Totals per provider were 104, 58, 49, 13, and 3 u/s assessments with 83%, 95%, 84%, 77%, and 100% adequacy of images, respectively. Of the 32 inadequate images, 18 of these were incomplete focused assessment with sonography for trauma (FAST) examinations with a reading of negative for free fluid.NPs are able to perform focused u/s with a high degree of accuracy, and a 16-h guideline-based course serves as a good introductory foundation.

    View details for DOI 10.1111/j.1745-7599.2010.00518.x

    View details for PubMedID 20590956

  • The utility of serial peak flow measurements in the acute asthmatic being treated in the ED. The American journal of emergency medicine Henderson, S. O., Ahern, T. L. 2010; 28 (2): 221-3

    Abstract

    Peak flow is used extensively in emergency departments (EDs) to both assess asthma patient's status on arrival as well as to document clinical improvement during treatment. Many algorithms suggest serial peak expiratory flow (PEF) measurements during an ED stay.The aim of the study was to assess the contribution of serial PEF in describing the overall improvement of asthmatics over the course of an ED visit for acute exacerbation of their asthma.This was a prospective institutional review board-approved study of mild/moderate asthmatics presenting to an inner-city ED serving a large Latino population. Peak expiratory flow was measured before treatment (baseline PEF) and after each inhaled treatment (PEF post RX#1, PEF post RX#2, PEF post RX#3) while in the ED.One hundred consecutive patients made up this study cohort. The change from baseline PEF to PEF #1 represented 86% (95% confidence interval [CI], 76%-96%) of the total improvement experienced by these patients with asthma. The change from PEF post RX#1 to PEF post RX#2 represented 7.5% (95% CI, -4.2% to 26%) of the total improvement and PEF post RX#2 to PEF post RX#3 represented 8.6% (95% CI, -1% to 34%) of the total PEF improvement seen.No correlation between outcome and PEF% of predicted was made or implied.The improvement in PEF seen after the first ED inhaled therapy appears to describe most of the total improvement seen in asthmatic patients. Subsequent PEFs provided little additional information.

    View details for DOI 10.1016/j.ajem.2008.10.031

    View details for PubMedID 20159395

  • Left ventricular hypertrophy may be transient in the emergency department. The western journal of emergency medicine Shoenberger, J. M., Voskanian, S., Johnson, S., Ahern, T., Henderson, S. O. 2009; 10 (3): 140-3

    Abstract

    While research has established that the bedside electrocardiogram (ECG) is an insensitive test for the presence or absence of left ventricular hypertrophy (LVH), the finding, when present, is thought to be reproducible.To assess the reproducibility of serial ECGs done in the emergency department (ED) with regard to the presence or absence of LVH.A prospective study on consecutive patients admitted to an ED-run cardiac observation unit. A single reviewer collected and scored ECGs for the presence of LVH, using three established criteria (Cornell, Sokolow-Lyon and Romhilt-Estes). Demographic and medical history was also collected.Over a three-year time period, 295 patients were enrolled; 132 males and 163 females with a mean age of 54.4 years (range, 19-89 years). The prevalence of LVH ranged from 11-14% and the agreement among all three criteria was fair (kappa = 0.325). Using the Cornell criteria, 33 patients had ECG#1 consistent with LVH. Of the patients meeting LVH criteria on ECG #1, only 15 retained their diagnosis of LVH on ECG#2 (i.e. 55% of the LVH identified in ECG#1 was not seen in ECG#2). Additionally, nine patients developed an ECG diagnosis of LVH between ECG#1 and ECG#2. In total, 27 (nine percent of the total) had ECG measurements that changed between ECG#1 and ECG#2. We made similar findings with the Sokolow-Lyon and Romhilt-Estes criteria. The results were not modified by gender, blood pressure or medication use.The finding of LVH on ECG was not very reproducible during serial measurements on the same person during a single 24-hour observation period.

    View details for PubMedID 19718372

    View details for PubMedCentralID PMC2729211

  • Tension pyothorax causing cardiac arrest. The western journal of emergency medicine Ahern, T. L., Miller, G. A. 2009; 10 (1): 61

    View details for DOI 10.1111/j.1442-2026.1998.tb00494.x

    View details for PubMedID 19561772

    View details for PubMedCentralID PMC2672290

  • Images in emergency medicine: traumatic pneumocephalus. The western journal of emergency medicine Ahern, T., Henderson, S. O. 2008; 9 (2): 123

    View details for PubMedID 19561721

    View details for PubMedCentralID PMC2672246