Impacts of United States Medical Licensing Examination Step 1 Scoring Change on Emergency Medicine Applicant Screening.

BACKGROUND: The U.S. Medical Licensing Examination (USMLE) Step 1 has been used as a screening tool for residency selection. In February 2020, Step 1 numerical scoring changed to pass/fail. OBJECTIVE: Our aim was to survey emergency medicine (EM) residency program attitudes towards the new Step 1 scoring change and to identify important applicant screening factors. METHODS: A 16-question survey was distributed through the Council of Residency Directors in Emergency Medicine listserv from November 11 through December 31, 2020. Given the Step 1 scoring change, the survey questioned the importance of EM rotation grades, composite standardized letters of evaluation (cSLOEs), and individual standardized letters of evaluation, using a Likert scale. Descriptive statistics of demographic characteristics and selection factors were performed along with a regression analysis. RESULTS: Of the 107 respondents, 48% were program directors, 28% were assistant or associate program directors, 14% were clerkship directors, and 10% were in other roles. Sixty (55.6%) disagreed with pass/fail Step 1 scoring change and, of those, 82% believed that numerical scoring was a good screening tool. The cSLOEs, EM rotation grades, and interview were the most important selection factors. Residencies with 50 or more residents had 5.25 odds (95% CI 1.25-22.1; p = 0.0018) of agreeing with pass/fail scoring and those who ranked cSLOEs as the most important selection factor had 4.90 odds (95% CI 1.125-21.37; p = 0.0343) of agreeing with pass/fail scoring. CONCLUSIONS: Most EM programs disagree with pass/fail scoring of Step 1 and will most likely use Step 2 score as a screening tool. The cSLOEs, EM rotation grades, and interview are considered the most important selection factors.

Hypoxia signatures in closed-circuit rebreather divers.

INTRODUCTION: Faults or errors during use of closed-circuit rebreathers (CCRs) can cause hypoxia. Military aviators face a similar risk of hypoxia and undergo awareness training to determine their 'hypoxia signature', a personalised, reproducible set of symptoms. We aimed to establish a hypoxia signature among divers, and to investigate their ability to detect hypoxia and self-rescue while cognitively overloaded. METHODS: Eight CCR divers and 12 scuba divers underwent an initial unblinded hypoxia exposure followed by three trials; a second hypoxic trial and two normoxic trials in randomised order. Hypoxia was induced by breathing on a CCR with no oxygen supply. Subjects pedalled on a cycle ergometer while playing a neurocognitive computer game to simulate real world task loading. Subjects identified hypoxia symptoms by pointing to a board listing common hypoxia symptoms, and were instructed to perform a 'bailout' procedure to mimic self-rescue if they perceived hypoxia. Divers were prompted to bailout if peripheral oxygen saturation fell to 75%, or after six minutes during normoxic trials. Subsequently we interviewed subjects to determine their ability to distinguish hypoxia from normoxia. RESULTS: Ninety-five percent of subjects (19/20) showed agreement between unblinded and blinded hypoxia symptoms. Subjects correctly identified the gas mixture in 85% of the trials. During unblinded hypoxia, only 25% (5/20) of subjects performed unprompted bailout. Fifty-five percent of subjects (11/20) correctly performed the bailout but only when prompted, while 15% (3/20) were unable to bailout despite prompting. During blinded hypoxia 45% of subjects (9/20) performed the bailout unprompted while 15% (3/20) remained unable to bailout despite prompting. CONCLUSIONS: Although our data support a normobaric hypoxia signature among both CCR and scuba divers under experimental conditions, most subjects were unable to recognise hypoxia in real time and perform a self-rescue unprompted, although this improved in the second hypoxia trial. These results do not support hypoxia exposure training for CCR divers.

Performance of the Uni-Vent Eagle™ Model 754 ventilator under hyperbaric conditions.

Critically ill patients needing mechanical ventilation may require hyperbaric oxygen therapy. Some institutions still use ventilators that were available prior to the advent of hyperbaric-specific units, such as the Uni-Vent Eagle™ Model model 754. Here we examine the performance of the Uni-Vent model 754 under hyperbaric conditions and investigate concerns of an oxygen leak in the ventilator housing, which poses a fire risk. We studied the ventilator at 1.0, 2.4 and 2.8 ATA in assist control mode using a Michigan test lung and a variety of tidal volumes and respiratory rates. We recorded the delivered volumes, peak pressures, and oxygen percentages within the hyperbaric chamber at 2.4 and 2.8 ATA and within the ventilator housing. At those pressures the ventilator delivered approximately 25% less volume than at 1.0 ATA. We observed breath stacking at high respiratory rates, but this was blunted at both 2.4 and 2.8 ATA. Oxygen levels did not rise in the housing during our investigation. In addition, we fit a linear regression to the data comparing set tidal volumes and delivered tidal volumes in order to model the changes observed. Hyperbaric conditions caused decreased delivered tidal volumes in a depth-dependent fashion, and oxygen levels within the housing did not rise. The Uni-Vent Eagle model 754 performed safely and effectively at depth but requires spirometry to correctly program desired ventilator settings.

Iatrogenic Arterial Gas Embolism From Esophagogastroduodenoscopy.

BACKGROUND: Arterial gas embolus (AGE) is a rare complication of esophagoduodenoscopy (EGD) that has been described in only a few case reports in the literature. The exact etiology remains unknown, but many of the cases share some common characteristics. CASE REPORT: We report the case of a 52-year-old otherwise healthy man who underwent outpatient EGD for a sensation of retained food in his esophagus. During the procedure, he suffered a tonic-clonic seizure, bradycardia, and hypoxia. Subsequent emergency department workup showed pneumocephalus on computed tomography brain imaging, and he was diagnosed with a cerebral AGE (CAGE). He was transferred to our facility for treatment of CAGE with hyperbaric oxygen therapy (HBOT). After multiple hyperbaric treatments, he was discharged with a residual left hemiparesis, which represented a significant improvement in his overall neurologic status. We also present a review of similar EGD CAGE cases from the literature and discuss their outcomes and the need for HBOT. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Although CAGE from EGD is rare, these patients will often be transferred to the ED from gastrointestinal procedural suites and an emergency physician should understand that an iatrogenic CAGE can result from this procedure and that CAGE is a clinical diagnosis. Definitive care at a critical care-capable hyperbaric chamber will provide the patient with the best chance of meaningful recovery, and transport should be arranged as expeditiously as possible.

Hyperbaric medicine simulation education curriculum: CNS toxicity during Treatment Table 6 and intubated ICU patient with mucous plugging.

INTRODUCTION/BACKGROUND: The incidence of complications and number of critically ill patients in hyperbaric medicine is relatively low [1]. This poses a challenge to those tasked with educating trainees as well as maintaining the skills of staff. Hyperbaric medicine fellows may not be exposed to critical patient scenarios or complications of hyperbaric medicine during a one-year fellowship. Additional staff may be unfamiliar with these situations as well. The purpose of hyperbaric simulation curriculum is to train health care providers for rare situations. To our knowledge, this hyperbaric simulation curriculum is the first published use of simulation education in the specialty of undersea and hyperbaric medicine. MATERIALS AND METHODS: Two simulation cases have been developed that involve a patient with oxygen toxicity during hyperbaric treatment as well as an ICU patient with mucous plugging. RESULTS: Medical training simulations are an effective method of teaching content and training multiple roles in Undersea and Hyperbaric Medicine. SUMMARY/CONCLUSIONS: A hyperbaric simulation curriculum is an achievable educational initiative that is able to train multiple team members simultaneously in situations that they may not encounter on a regular basis. We believe that this could be easily exported to otherinstitutions for further education.

Fatal pulmonary embolism update: 10 years of autopsy experience at an academic medical center.

OBJECTIVE: To investigate the rate of death caused by pulmonary embolism (PE) and the antemortem performance in diagnosis and treatment of PE. DESIGN: A systematic search of cases involving fatal PE via PowerPath® (Sunquest) followed by chart review. SETTING: An academic medical centre located in San Diego, United States of America. PARTICIPANTS: Postmortem cases with pathological findings of PE. MAIN OUTCOME MEASURES: After data collection and collation, the data were subject to analysis. RESULTS: From 2002 to 2012, PE was identified as the mechanism of death in 108 of 982 cases (11%, 95% CI 9.01-12.99%) at an institution with an average autopsy rate of 30% ± 0.07%. Excluding cases where care was withheld (by advance directive) or unavailable, 29 of 108 were eligible for antemortem treatment for PE. In 31% (nine of 29) of these cases the diagnosis of PE was considered antemortem. Only three of 29 were given thrombolytics despite only one case being contraindicated. CONCLUSION: The rate of PE-related death is consistent with most other autopsy series and major epidemiologic studies despite advances in system wide deep venous thrombosis prophylaxis. The results validate previous studies that this diagnosis is often missed but probably improving compared to historical standards. Even when the diagnosis is considered, however, thrombolytics are not routinely given, even without contraindications. The cause of this failure to treat may require further study with comparison to patients that were treated to determine the utilization of this treatment. It also underscores the continued difficulty in the diagnosis of this disease.

Common hand sanitizer may distort readings of breathalyzer tests in the absence of acute intoxication.

OBJECTIVES: The use of alcohol-based hand sanitizers has recently become widespread. To the authors' knowledge, no previous study has examined whether application of ethanol-based hand sanitizers by the person operating a common breathalyzer machine will affect the accuracy of the readings. This was a prospective study investigating whether the use of hand sanitizer applied according to manufacturer's recommendations (Group I), applied improperly at standard doses (Group II), or applied improperly at high doses (Group III) had an effect on breathalyzer readings of individuals who had not ingested alcohol. METHODS: The participants of the prospective study were divided into three groups to assess the effect of hand sanitizer on breathalyzer readings. Group I used one pump (1.5 mL) of hand sanitizer (Purell), allowing the hands to dry per manufacturer's recommendations; Group II used one pump (1.5 mL), without allowing the hands to dry; and Group III used two pumps (3 mL), without allowing the hands to dry. Breathalyzer measures for each group are presented as medians with interquartile ranges (IQR) and ranges. Differences between each sequential group (I vs. II and II vs. III) were assessed using a Mann-Whitney U-test (p < 0.05 significant). RESULTS: There were 25 study participants in each group for a total of 75 participants. The initial breathalyzer readings of all study participants were 0.000 g/dL. The median breathalyzer reading was 0.004 g/dL in Group I (IQR = 0.001 to 0.008 g/dL), 0.051 g/dL in Group II (IQR = 0.043 to 0.064 g/dL), and 0.119 g/dL in Group III (IQR = 0.089 to 0.134 g/dL). Measures between each subsequent group were all statistically different (p < 0.001). CONCLUSIONS: The use of common alcohol-based hand sanitizer may cause false-positive readings with a standard hospital breathalyzer when the operator uses the hand sanitizer correctly. The breathalyzer readings are further elevated if more sanitizer is used or if it is not allowed to dry appropriately.

Safe emergency department removal of a hardened steel penile constriction ring.

BACKGROUND: Penile constriction devices are used for the enhancement of sexual performance. These devices have the potential to become incarcerated, leading to necrosis and amputation if not removed promptly. OBJECTIVE: This article presents a step-by-step approach for the safe removal of a hardened steel penile constriction device using somewhat unorthodox tools found in a hospital. CASE REPORT: We present a case of an incarcerated hardened steel penile constriction ring that was not able to be removed with conventional techniques. We describe a novel technique using an electric grinder and laryngoscope blade. CONCLUSION: The technique described in this article is a valuable and relatively safe technique for the Emergency Physician to facilitate the timely removal of a hardened steel constriction device.