Background: Hemorrhage control prior to shock onset is increasingly recognized as a time-critical intervention. Although tourniquets (TQs) have been demonstrated to save lives, less is known about the physiologic parameters underlying successful TQ application beyond palpation of distal pulses. The current study directly visualized distal arterial occlusion via ultrasonography and measured associated pressure and contact force. Methods: Fifteen tactical officers participated as live models for the study. Arterial occlusion was performed using a standard adult blood pressure (BP) cuff and a Combat Application Tourniquet Generation 7 (CAT7) TQ, applied sequentially to the left mid-bicep. Arterial flow cessation was determined by radial artery palpation and brachial artery pulsed wave doppler ultrasound (US) evaluation. Steady state maximal generated force was measured using a thin-film force sensor. Results: The mean (95% CI) systolic blood pressure (SBP) required to occlude palpable distal pulse was 112.9mmHg (109-117); contact force was 23.8N [Newton] (22.0-25.6). Arterial flow was visible via US in 100% of subjects despite lack of palpable pulse. The mean (95% CI) SBP and contact force to eliminate US flow were 132mmHg (127-137) and 27.7N (25.1-30.3). The mean (95% CI) number of windlass turns to eliminate a palpable pulse was 1.3 (1.0-1.6) while 1.6 (1.2-1.9) turns were required to eliminate US flow. Conclusions: Loss of distal radial pulse does not indicate lack of arterial flow distal to upper extremity TQ. On average, an additional one-quarter windlass turn was required to eliminate distal flow. Blood pressure and force measurements derived in this study may provide data to guide future TQ designs and inexpensive, physiologically accurate TQ training models.

Introduction Limited information exists regarding the response of helicopter EMS programs to patients with known or suspected COVID-19. The purpose of this study was to determine changes in flight operations during the early stages of the pandemic. Methods Survey of American College of Emergency Physicians Air Medical Section was conducted between 5/13/2020 and 8/1/2020. COVID-19 prevalence was defined as high vs low based upon cases > 2500 or ≤ 2500. Results Of 48 respondents, the majority (89.6%) reported that their patient guidelines had changed due to COVID-19. 89.6% of programs reported transporting COVID-19 positive patients while 91.5% reported transporting persons under investigation (PUI). The majority of respondents reported additional training in COVID-19 airway management (79.2%) and PPE use (93.6%). Permitted aerosol-generating procedures (AGPs) included BiPAP (40.4%) and high-flow nasal oxygen (66.0%). No difference in guideline changes, positive COVID-19/PUI transport restrictions, or permitted AGPs were noted between high and low prevalence settings. Conclusion COVID-19 has resulted in changes to HEMS guidelines regardless of local disease prevalence. The pandemic has persisted sufficiently long that data regarding the effectiveness of guideline changes should be analyzed. In the absence of definitive data, national best practices should be developed to guide COVID-19 HEMS transport.

Background: After officer-involved shootings (OIS), rapid delivery of emergency medical care is critical but may be delayed due to scene safety concerns. The purpose of this study was to describe medical care rendered by law enforcement officers (LEOs) after lethal force incidents. Methods: Retrospective analysis of open-source video footage of OIS occurring from February 15, 2013 through December 31, 2020. Frequency and nature of care provided, time until LEO and Emergency Medical Services (EMS) care, and mortality outcomes were evaluated. The study was deemed exempt by the Mayo Clinic Institutional Review Board. Results: Three hundred forty-two (342) videos were included in the final analysis; LEOs rendered care in 172 (50.3%) incidents. Average elapsed time from time-of-injury (TOI) to LEO-provided care was 155.8 (SD = 198.8) seconds. Hemorrhage control was the most common intervention performed. An average of 214.2 seconds elapsed between LEO care and EMS arrival. No mortality difference was identified between LEO versus EMS care (P = .1631). Subjects with truncal wounds were more likely to die than those with extremity wounds (P < .00001). Conclusions: It was found that LEOs rendered medical care in one-half of all OIS incidents, initiating care on average 3.5 minutes prior to EMS arrival. Although no significant mortality difference was noted for LEO versus EMS care, this finding must be interpreted cautiously, as specific interventions, such as extremity hemorrhage control, may have impacted select patients. Future studies are needed to determine optimal LEO care for these patients.

Introduction:After officer-involved shootings, rapid delivery of emergency medical care is critical but may be delayed due to scene safety concerns. The purpose of this study was to describe medical care rendered by law enforcement officers (LEO) after lethal force incidents.Method:Retrospective analysis of open-source video footage of officer-involved shootings (OIS) occurring between 2/15/2013 and 12/31/2020. Frequency and nature of care provided, time until LEO and emergency medical services (EMS) care, and mortality outcomes were evaluated. The study was deemed exempt by the Mayo Clinic Institutional Review Board.Results:342 videos were included in the final analysis. LEOs rendered care in 172 (50.3%) incidents. The average elapsed time from the time of injury to LEO-provided care was 155.8 + 198.8 seconds. Hemorrhage control was the most common intervention performed. An average of 214.2 seconds elapsed between LEO care and EMS arrival. No mortality difference was identified between LEO vs EMS care (p = 0.1631). Subjects with truncal wounds were more likely to die than those with extremity wounds (p < 0.00001).Conclusion:LEO rendered medical care in half of all OIS incidents, initiating care on average 3.5 minutes prior to EMS arrival. Although no significant mortality difference was noted for LEO versus EMS care, this finding must be interpreted cautiously, as specific interventions, such as extremity hemorrhage control, may have impacted select patients. Future studies are needed to determine optimal LEO care for these patients.