The Efficacy of Whole Blood Resuscitation During Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) to Mitigate Post-occlusion Circulatory Collapse: A Translational Model in Large Swine.

INTRODUCTION: Uncontrolled torso hemorrhage is the primary cause of potentially survivable deaths on the battlefield. Zone 1 Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA), in conjunction with damage control resuscitation, may be an effective management strategy for these patients in the prehospital or austere phase of their care. However, the effect of whole blood (WB) transfusion during REBOA on post-occlusion circulatory collapse is not fully understood. MATERIALS AND METHODS: Yorkshire male swine (n = 6 per group, 70-90 kg) underwent a 40% volume-controlled hemorrhage. After a 10-minute hemorrhagic shock period, a REBOA balloon was inflated in Zone 1. Fifteen minutes after inflation, 0, 1, or 3 units (450 mL/unit) of autologous WB was infused through the left jugular vein. Thirty minutes after initial balloon inflation, the balloon was deflated slowly over 3 minutes. Following deflation, normal saline was administered (up to 3,000 mL) and swine were observed for 2 hours. Survival (primary outcome), hemodynamics, and blood gas values were compared among groups. Statistical significance was determined by log-rank test, one-way ANOVA, and repeated measures ANOVA. RESULTS: Survival rates were comparable between groups (P = .345) with 66% of control, 33% of the one-unit animals, and 50% of the 3-unit animals survived until the end of the study. Following WB infusion, both the 1-unit and the 3-unit groups had significantly higher blood pressure (P < .01), pulmonary artery pressure (P < .01), and carotid artery flow (P < .01) compared to the control group. CONCLUSIONS: WB transfusion during Zone 1 REBOA was not associated with increased short-term survival in this large animal model of severe hemorrhage. We observed no signal that WB transfusion may mitigate post-occlusion circulatory collapse. However, there was evidence of supra-normal blood pressures during WB transfusion.

Associations with Prehospital Antibiotic Receipt among Combat Casualties with Open Wounds: A Department of Defense Trauma Registry Study.

INTRODUCTION: Current Tactical Combat Casualty Care (TCCC) guidelines recommend antibiotic administration for all open wounds to prevent infection. We identified associations between demographics, procedures, and medicines with the receipt of prehospital antibiotics among combat casualties. MATERIALS AND METHODS: We used a series of emergency department procedure codes to identify adult subjects within the Department of Defense Trauma Registry from January 2007 to August 2016 who sustained open wounds. We compared demographics, procedures, and medicines administered among casualties receiving prehospital wound prophylaxis versus casualties not receiving antibiotic prophylaxis. We controlled for confounders with multivariable logistical regression. RESULTS: We identified 18,366 encounters meeting inclusion criteria. Antibiotic recipients (n = 2384) were comparable to nonrecipients (n = 15,982) with regard to age and sex. Antibiotic recipients were more likely to sustain injuries from firearms and undergo all procedures examined related to hemorrhage control, airway management, pneumothorax treatment, and volume replacement except for intraosseous access. Antibiotic recipients were less likely to sustain injuries from explosives. Antibiotic recipients had a modestly higher survival than nonrecipients (97.4% versus 96.0%). Associations with prehospital antibiotic receipt in multivariable logistic regression included non-North Atlantic Treaty Organization military force affiliation (odds ratio (OR) 4.65, 95% CI, 1.0-20.8), tachycardia (OR 3.4, 95% CI, 1.1-10.5), intubation (OR 2.0, 95% CI, 1.1-3.8), and administration of tranexamic acid (OR 5.6, 95% CI, 1.2-26.5). CONCLUSIONS: The proportion of combat casualties with open wounds receiving prehospital antibiotics was low despite published recommendations for early antibiotics in patients with open wounds. These findings highlight the ongoing need for additional educational and quality assurance initiatives to continue improving adherence to TCCC guidelines with regard to prehospital antibiotic administration. Future studies are necessary to determine reasons for suboptimal TCCC guideline compliance.

Patterns of Palliation: A Review of Casualties That Received Pain Management Before Reaching Role 2 in Afghanistan.

INTRODUCTION: Battlefield pain management changed markedly during the first 20 years of the Global War on Terror. Morphine, long the mainstay of combat analgesia, diminished in favor of fentanyl and ketamine for military pain control, but the options are not hemodynamically or psychologically equivalent. Understanding patterns of prehospital analgesia may reveal further opportunities for combat casualty care improvement. MATERIALS AND METHODS: Using Department of Defense Trauma Registry data for the Afghanistan conflict from 2005 to 2018, we examined 2,402 records of prehospital analgesia administration to assess temporal trends in medication choice and proportions receiving analgesia, including subanalysis of a cohort screened for an indication with minimal contraindication for analgesia. We further employed frequency matching to explore the presence of disparities in analgesia by casualty affiliation. RESULTS: Proportions of documented analgesia increased throughout the study period, from 0% in 2005 to 70.6% in 2018. Afghan casualties had the highest proportion of documented analgesia (53.0%), versus U.S. military (31.9%), civilian/other (23.3%), and non-U.S. military (19.3%). Fentanyl surpassed morphine in the frequency of administration in 2012. The median age of those receiving ketamine was higher (30 years) than those receiving fentanyl (26 years) or nonsteroidal anti-inflammatory drugs (23 years). Among the frequency-matched subanalysis, the odds ratio for ketamine administration with Afghan casualties was 1.84 (95% CI, 1.30-2.61). CONCLUSIONS: We observed heterogeneity of prehospital patient care across patient affiliation groups, suggesting possible opportunities for improvement toward an overall best practice system. General increase in documented prehospital pain management likely reflects efforts toward complete documentation, as well as improved options for analgesia. Current combat casualty care documentation does not include any standardized pain scale.

Prehospital Ultrasound Use to Guide Resuscitative Thoracotomy in Blunt Traumatic Cardiac Arrest.

Traumatic cardiac arrest is frequently encountered in the air medical transport environment, and resuscitative thoracotomy is a procedure that is sometimes performed in an attempt to salvage these critically injured patients. Focused assessment with sonography for trauma (FAST) is a point-of-care ultrasound protocol commonly used in trauma patients to detect the presence of free fluid in the intraperitoneal and pericardial spaces. The authors present a case of an adult female victim of a motor vehicle collision whose prehospital FAST scan revealed significant hemoperitoneum without hemopericardium. When she developed cardiac arrest, these ultrasound findings aided in the decision to perform resuscitative thoracotomy and helped guide the sequence of maneuvers with prioritization given to cross-clamping the aorta. This case highlights the utility of prehospital ultrasound in yielding timely, actionable diagnostic information that can inform the performance of a high-acuity low-occurrence procedure in the air medical transport environment.

Prospective Randomized Trial of Standard Left Anterolateral Thoracotomy Versus Modified Bilateral Clamshell Thoracotomy Performed by Emergency Physicians.

STUDY OBJECTIVE: Resuscitative thoracotomy is a time-sensitive, lifesaving procedure that may be performed by emergency physicians. The left anterolateral thoracotomy (LAT) is the standard technique commonly used in the United States to gain rapid access to critical intrathoracic structures. However, the smaller incision and subsequent limited exposure may not be optimal for the nonsurgical specialist to complete time-sensitive interventions. The modified bilateral anterior clamshell thoracotomy (MCT) developed by Barts Health NHS Trust clinicians at London's Air Ambulance overcomes these inherent difficulties, maximizes thoracic cavity visualization, and may be the ideal technique for the nonsurgical specialist. The aim of this study is to identify the optimal technique for the nonsurgical-specialist-performed resuscitative thoracotomy. Secondary aims of the study are to identify technical difficulties, procedural concerns, and physician preferences. METHODS: Emergency medicine staff and senior resident physicians were recruited from an academic Level I trauma center. Subjects underwent novel standardized didactic and skills-specific training on both the MCT and LAT techniques. Later, subjects were randomized to the order of intervention and performed both techniques on separate fresh, nonfrozen human cadaver specimens. Success was determined by a board-certified surgeon and defined as complete delivery of the heart from the pericardial sac and subsequent 100% occlusion of the descending thoracic aorta with a vascular clamp. The primary outcome was time to successful completion of the resuscitative thoracotomy technique. Secondary outcomes included successful exposure of the heart, successful descending thoracic aortic cross clamping, successful procedural completion, time to exposure of the heart, time to descending thoracic aortic cross-clamp placement, number and type of iatrogenic injuries, correct anatomic structure identification, and poststudy participant questionnaire. RESULTS: Sixteen emergency physicians were recruited; 15 met inclusion criteria. All participants were either emergency medicine resident (47%) or emergency medicine staff (53%). The median number of previously performed training LATs was 12 (interquartile range 6 to 15) and the median number of previously performed MCTs was 1 (interquartile range 1 to 1). The success rates of our study population for the MCT and LAT techniques were not statistically different (67% versus 40%; difference 27%; 95% confidence interval -61% to 8%). However, staff emergency physicians were significantly more successful with the MCT compared with the LAT (88% versus 25%; difference 63%; 95% CI 9% to 92%). Overall, the MCT also had a significantly higher proportion of injury-free trials compared with the LAT technique (33% versus 0%; difference 33%; 95% CI 57% to 9%). Physician procedure preference favored the MCT over the LAT (87% versus 13%; difference 74%; 95% CI 23% to 97%). CONCLUSION: Resuscitative thoracotomy success rates were lower than expected in this capable subject population. Success rates and procedural time for the MCT and LAT were similar. However, the MCT had a higher success rate when performed by staff emergency physicians, resulted in less periprocedural iatrogenic injuries, and was the preferred technique by most subjects. The MCT is a potentially feasible alternative resuscitative thoracotomy technique that requires further investigation.

Development and Evaluation of An Abbreviated Extracorporeal Membrane Oxygenation (ECMO) Course for Nonsurgical Physicians and Nurses.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) is a modification of cardiopulmonary bypass that allows prolonged support of patients with severe respiratory or cardiac failure. ECMO indications arse rapidly evolving and there is growing interest in its use for cardiac arrest and cardiogenic shock. However, ECMO training programs are limited. Training of emergency medicine and critical care clinicians could expand the use of this lifesaving intervention. Our objective was to develop and evaluate an abbreviated ECMO course that can be taught to emergency and critical care physicians and nurses. METHODS: We developed a training model using Yorkshire swine (Sus scrofa), a procedure instruction checklist, a confidence assessment, and a knowledge assessment. Participants were assigned to teams of one emergency medicine or critical care physician and one nurse and completed an abbreviated 8-hour ECMO course. An ECMO specialist trained participants on preparation of the ECMO circuit and oversaw vascular access and ECMO initiation. We used the instruction checklist to evaluate performance. Participants completed confidence and knowledge assessments before and after the course. RESULTS: Seventeen teams (34 clinicians) completed the abbreviated ECMO course. None had previously completed an ECMO certification course. Immediately following the course, all teams successfully primed and prepared the ECMO circuit. Fifteen teams (88%, 95% confidence interval [CI] = 64% to 99%) successfully initiated ECMO. Participants improved their knowledge (difference 21.2, 95% CI = 16.5 to 25.8) and confidence (difference 40.3, 95% CI = 35.6 to 45.0) scores after completing the course. CONCLUSIONS: We developed an accelerated 1-day ECMO course. Clinicians' confidence and knowledge assessments improved and 88% of teams could successfully initiate venoarterial ECMO after the course.

Prehospital Transfusion of Low-Titer O + Whole Blood for Severe Maternal Hemorrhage: A Case Report.

Introduction: Beginning in 2017, multiple stakeholders within the Southwest Texas Regional Advisory Council for Trauma collaborated to incorporate cold-stored low-titer O RhD-positive whole blood (LTO + WB) into all phases of their trauma system, including the prehospital phase of care. Although the program was initially focused on trauma resuscitation, it was expanded to included non-traumatic hemorrhagic shock patients that may benefit from whole blood resuscitation.Case Report: We report the case of a patient with severe maternal hemorrhage secondary to placenta accreta who received a prehospital transfusion of LTO + WB. We believe this to be the first reported case of post-partum hemorrhage resuscitated out of hospital with whole blood.Discussion: This case highlights the potential benefits of a prehospital whole blood program as well as the controversy surrounding a LTO + WB program that includes females of childbearing age.

No Benefit in Neurologic Outcomes of Survivors of Out-of-Hospital Cardiac Arrest with Mechanical Compression Device.

INTRODUCTION: Out-of-hospital cardiac arrest (OHCA) is a major cause of death and morbidity in the United States. Quality cardiopulmonary resuscitation (CPR) has proven to be a key factor in improving survival. The aim of our study was to investigate the outcomes of OHCA when mechanical CPR (LUCAS 2 Chest Compression System™) was utilized compared to conventional CPR. Although controlled trials have not demonstrated a survival benefit to the routine use of mechanical CPR devices, there continues to be an interest for their use in OHCA. METHODS: We conducted a retrospective observational study of OHCA comparing the outcomes of mechanical and manual chest compressions in a fire department based EMS system serving a population of 1.4 million residents. Mechanical CPR devices were geographically distributed on 11 of 33 paramedic ambulances. Data were collected over a 36-month period and outcomes were dichotomized based on utilization of mechanical CPR. The primary outcome measure was survival to hospital discharge with a cerebral performance category (CPC) score of 1 or 2. RESULTS: This series had 3,469 OHCA reports, of which 2,999 had outcome data and met the inclusion criteria. Of these 2,236 received only manual CPR and 763 utilized a mechanical CPR device during the resuscitation. Return of spontaneous circulation (ROSC) was attained in 44% (334/763) of the mechanical CPR resuscitations and in 46% (1,020/2,236) of the standard manual CPR resuscitations (p = 0.32). Survival to hospital discharge was observed in 7% (52/763) of the mechanical CPR resuscitations and 9% (191/2,236) of the manual CPR group (p = 0.13). Discharge with a CPC score of 1 or 2 was observed in 4% (29/763) of the mechanical CPR resuscitation group and 6% (129/2,236) of the manual CPR group (p = 0.036). CONCLUSIONS: In our study, use of the mechanical CPR device was associated with a poor neurologic outcome at hospital discharge. However, this difference was no longer evident after logistic regression adjusting for confounding variables. Resuscitation management following institution of mechanical CPR, specifically medication and airway management, may account for the poor outcome reported. Further investigation of resuscitation management when a mechanical CPR device is utilized is necessary to optimize survival benefit.