A prospective, pragmatic non-inferiority study of emergency intubation success with the single-use i-view versus standard reusable video laryngoscope.

INTRODUCTION: Video laryngoscope (VL) technology improves first-pass success. The novel i-view VL device is inexpensive and disposable. We sought to determine the first-pass intubation success with the i-view VL device versus the standard reusable VL systems in routine use at each site. METHODS: We performed a prospective, pragmatic study at two major emergency departments (EDs) when VL was used. We rotated i-view versus reusable VL as the preferred device of the month based on an a priori schedule. An investigator-initiated interim analysis was performed. Our primary outcome was a first-pass success with a non-inferiority margin of 10% based on the per-protocol analysis. RESULTS: There were 93 intubations using the reusable VL devices and 81 intubations using the i-view. Our study was stopped early due to futility in reaching our predetermined non-inferiority margin. Operator and patient characteristics were similar between the two groups. The first-pass success rate for the i-view group was 69.1% compared to 84.3% for the reusable VL group. A non-inferiority analysis indicated that the difference (-15.1%) and corresponding 90% confidence limits (-25.3% to -5.0%) did not fall within the predetermined 10% non-inferiority margin. CONCLUSIONS: The i-view device failed to meet our predetermined non-inferiority margin when compared to the reusable VL systems with the study stopping early due to futility. Significant crossover occurred at the discretion of the intubating operator during the i-view month.

Hypothermia in the Combat Trauma Population.

BACKGROUND: The MARCH (Massive hemorrhage, Airway, Respirations, Circulation, and Hypothermia/Head injuries) algorithm taught to military medics includes interventions to prevent hypothermia. As possible sequelae from major trauma, hypothermia is associated with coagulopathy and lower survival. This paper sought to define hypothermia within our combat trauma population using an outcomes-based method, and determine clinical variables associated with hypothermia. METHODS: This is a secondary analysis of a previously described dataset from the Department of Defense Trauma Registry focused on casualties who received prehospital care. A receiver operating curve was constructed and Youden's index was used to define hypothermia within the predetermined population based on mortality risk. A multivariable regression model was used to identify associations. RESULTS: There were 23,243 encounters that met the inclusion criteria for this study with patients having received prehospital care and documentation of at least one emergency department temperature. An optimal threshold of 36.2° C was found to predict mortality; 3,159 casualties had temperatures below this threshold (14%). Survival to discharge was lower among casualties with hypothermia (91% versus 98%). Hypothermic casualties were less likely to undergo blanket application (38% versus 40%). However, they had higher proportions with Hypothermia Prevention and Management Kit application (11% versus 7%) and radiant warming (2% versus 1%). On multivariable regression modeling, none of the hypothermia interventions were associated with a decreased likelihood of hypothermia. Non-hypothermia interventions associated with hypothermia included prehospital intubation (OR 1.57, 95% CI 1.45-1.69) and blood product administration. CONCLUSIONS: Hypothermia, including a single recorded low temperature in the patient care record, was associated with worse outcomes in this combat trauma population. Prehospital intubation was most strongly associated with developing hypothermia. Prehospital warming interventions were not associated with a reduction in hypothermia risk. Our dataset suggests that current methods for prehospital warming are inadequate.

High risk and low prevalence diseases: Toxic alcohol ingestion.

INTRODUCTION: Toxic alcohol ingestion is a rare but serious condition that carries with it a high rate of morbidity and mortality. OBJECTIVE: This review highlights the pearls and pitfalls of toxic alcohol ingestion, including presentation, diagnosis, and management in the emergency department (ED) based on current evidence. DISCUSSION: Toxic alcohols include ethylene glycol, methanol, isopropyl alcohol, propylene glycol, and diethylene glycol. These substances can be found in several settings including hospitals, hardware stores, and the household, and ingestion can be accidental or intentional. Toxic alcohol ingestion presents with various degrees of inebriation, acidemia, and end-organ damage depending on the substance. Timely diagnosis is critical to prevent irreversible organ damage or death and is based primarily on clinical history and consideration of this entity. Laboratory evidence of toxic alcohol ingestion includes worsening osmolar gap or anion-gap acidemia and end organ injury. Treatment depends on the ingestion and severity of illness but includes alcohol dehydrogenase blockade with fomepizole or ethanol and special considerations for the initiation of hemodialysis. CONCLUSIONS: An understanding of toxic alcohol ingestion can assist emergency clinicians in diagnosing and managing this potentially deadly disease.

Ketamine during resuscitation - Is it as hemodynamically perfect as we think?

INTRODUCTION: Ketamine administration in patients experiencing or at risk for hypotension is common based upon the presumption of this agent's favorable hemodynamic profile. The Compensatory Reserve Measurement (CRM) is a novel algorithm that accurately tracks systemic adequacy for delivery of oxygen (DO2) to the tissues. We present a case series of trauma patients receiving ketamine with CRM measurements to offer insight into the DO2 during resuscitation. METHODS: We captured vital signs along with analog arterial waveform data from trauma patients meeting major activation criteria using a prospective study design. Study team members tracked interventions and vital signs including systolic blood pressure (SBP), mean arterial pressure (MAP), and heart rate (HR) throughout their emergency department stay. RESULTS: Our study included 8 patients who received ketamine for intubation or analgesia (20-300 mg) and had adequate data for analysis. Most were male (88%) with a median age of 28. The most common mechanisms of injury were motor vehicle collisions (MVCs) (38%) and gunshot wounds (38%). After ketamine administration SBP, MAP, and HR all increased while the CRM exhibited minimal change. CONCLUSIONS: SBP, MAP, and HR generally appeared to increase while the CRM remained unchanged. Our findings suggest that while standard vital sign measurements appear to increase, ketamine may not improve delivery of oxygen to the tissues. This warrants further study to better understand the effects of ketamine on hemodynamics.

Efficacy of the compensatory reserve measurement in an emergency department trauma population.

BACKGROUND: The Compensatory Reserve Measurement (CRM) is a novel method used to provide early assessment of shock based on arterial wave form morphology changes. We hypothesized that (1) CRM would be significantly lower in those trauma patients who received life-saving interventions compared with those not receiving interventions, and (2) CRM in patients who received interventions would recover after the intervention was performed. STUDY DESIGN AND METHODS: We captured vital signs along with analog arterial waveform data from trauma patients meeting major activation criteria using a prospective study design. Study team members tracked interventions throughout their emergency department stay. RESULTS: Ninety subjects met inclusion with 13 receiving a blood product and 10 a major airway intervention. Most trauma was blunt (69%) with motor vehicle collisions making up the largest proportion (37%) of injury mechanism. Patients receiving blood products had lower CRM values just prior to administration versus those who did not (50% versus 58%, p = .045), and lower systolic pressure (SBP; 95 versus 123 mmHg, p = .005), diastolic (DBP; 62 versus 79, p = .007), and mean arterial pressure (MAP; 75 versus 95, p = .006), and a higher pulse rate (HR; 101 versus 89 bpm, p = .039). Patients receiving an airway intervention had lower CRM values just prior to administration versus those who did not (48% versus 58%, p = .062); however, SBP, DBP, MAP, and HR were not statistically distinguishable (p ≥ .645). CONCLUSIONS: Our results support our hypotheses that the CRM distinguished those patients who received blood or an airway intervention from those who did not, and increased appropriately after interventions were performed.

The Effect of Chest Compression Location and Aortic Perfusion in a Traumatic Arrest Model.

BACKGROUND: Recent evidence demonstrates that closed chest compressions directly over the left ventricle (LV) in a traumatic cardiac arrest (TCA) model improve hemodynamics and return of spontaneous circulation (ROSC) when compared to traditional compressions. Selective aortic arch perfusion (SAAP) also improves hemodynamics and controls hemorrhage in TCA. We hypothesized that chest compressions located over the LV would result in improved hemodynamics and ROSC in a swine model of TCA using SAAP. MATERIALS AND METHODS: Transthoracic echo was used to mark the location of the aortic root (Traditional location) and the center of the LV on animals (n = 24), which were randomized to receive chest compressions in one of the two locations. After hemorrhage, ventricular fibrillation (VF) was induced to simulate TCA. After a period of 10 min of VF, basic life support (BLS) with mechanical CPR was initiated and performed for 10 min, followed by advanced life support (ALS) for an additional 10 min. SAAP balloons were inflated at min 6 of BLS. Hemodynamic variables were averaged over the final 2 min of the BLS and ALS periods. Survival was compared between this SAAP cohort and a control group without SAAP (No-SAAP) (n = 26). RESULTS: There was no significant difference in ROSC between the two SAAP groups (P = 0.67). There was no ROSC difference between SAAP and No-SAAP (P = 0.74). CONCLUSIONS: There was no difference in ROSC between LV and Traditional compressions when SAAP was used in this swine model of TCA. SAAP did not confer a survival benefit compared to historical controls.

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.

Impact of a Standardized Patient Hand-off Tool on Communication between Emergency Medical Services Personnel and Emergency Department Staff.

INTRODUCTION: Handoff communication between Emergency Medical Services (EMS) and Emergency Department (ED) staff is critical to ensure quality patient care. In January 2016, the Southwest Texas Regional Advisory Council (STRAC) implemented MIST (Mechanism, Injuries, vital Signs, Treatments), a standardized EMS to ED handoff tool. The En route Care Research Center conducted a Pre-MIST implementation survey of ED staff in December 2015 and a Post-MIST follow-up survey in July 2017 to determine the impact of the MIST handoff tool on the perceived quality of transmission of pertinent patient information and in the overall handoff experience. METHODS: We administered a nine-item Likert scale questionnaire to Brooke Army Military Medical Center (BAMC) ED providers and nurses before and after implementation of MIST. The questionnaire captured perceived competence and satisfaction with handoff communication (Cronbach's alpha 0.73). We analyzed responses for the total sample and by occupation (providers and nurses), and we calculated odds ratios to determine items that may be most predictive of a positive handoff experience from the perspective of the ED staff. We performed chi-square tests and reported data as percentages. RESULTS: Total respondents Pre- and Post-MIST were 128 (62%) nurses and 80 (38%) providers (MDs, DOs, and PAs). Following the implementation of MIST, more respondents reported that they were "informed of prehospital treatments" (p < 0.001), that "Red/Blue Trauma Alert Criteria were conveyed" (p < 0.001), and that the "time to give the report was sufficient to convey pertinent information" (p < 0.001). Nurses more frequently reported that "Red/Blue Trauma Alert Criteria were conveyed" post-MIST (p < 0.01). Providers more frequently reported that "Assessment findings were conveyed" (p < 0.05), that they 'interrupted the report for clarification" (p < 0.04), that "time to give the report was sufficient to convey pertinent information" (p < 0.001) and that they "felt positive about the overall handoff experience" (p < 0.03) Post-MIST. Overall satisfaction with the handoff was associated with frequently being informed of prehospital treatments (OR 5.5; 2.1-14.4) and frequently receiving a copy of the prehospital record (OR 2.9; 1.1-7.2). CONCLUSIONS: These data demonstrate that providers and nurses reported an improvement in the handoff experience Post-MIST. This study supports the use of a standardized handoff tool at this critical step in patient care.

Impact of a Standardized EMS Handoff Tool on Inpatient Medical Record Documentation at a Level I Trauma Center.

BACKGROUND: The emergency department (ED) poses challenges to effective handoff from emergency medical services (EMS) personnel to ED staff. Despite the importance of a complete and accurate patient handoff report between EMS and trauma staff, communication is often interrupted, incomplete, or otherwise ineffective. The Mechanism of injury/Medical Complaint, Injuries or Inspections head to toe, vital Signs, and Treatments (MIST) report initiative was implemented to standardize the handoff process. The objective of this study was to evaluate whether documentation of prehospital care in the inpatient medical record improved after MIST implementation. METHODS: Research staff abstracted data from the EMS and inpatient medical records of trauma patients transported by EMS and treated at a Level I trauma center from January 2015 through June 2017. Data included patient demographics, mechanism and location of injury, vital signs, treatments, and period of data collection (pre-MIST and post-MIST). We summarized the MIST elements in EMS and inpatient medical records and assessed the presence or absence of data elements in the inpatient record from the EMS record and the agreement between the two sets of records over time to determine if implementation of MIST improved documentation. RESULTS: We analyzed data from 533 trauma patients transported by EMS and treated in a Level I trauma center (pre-MIST: n = 281; post-MIST: n = 252). For mechanism of injury, agreement between the two records was ≥96% before and after MIST implementation. Cardiac arrest and location of injury were under-reported in the inpatient record before MIST; post-MIST, there were no significant discrepancies, indicating an improvement in reporting. Reporting of prehospital hypotension improved from 76.5% pre-MIST to 83.3% post-MIST. After MIST implementation, agreement between the EMS and inpatient records increased for the reporting of fluid administration (45.6% to 62.7%) and decreased for reporting of pain medications (72.2% to 61.9%). CONCLUSIONS: The use of the standardized MIST tool for EMS to hospital patient handoff was associated with a mixed value on inpatient documentation of prehospital events. After MIST implementation, agreement was higher for mechanism and location of injury and lower for vital signs and treatments. Further research can advance the prehospital to treatment facility handoff process.

Intramuscular cobinamide as an antidote to methyl mercaptan poisoning.

BACKGROUND: Methyl mercaptan occurs naturally in the environment and is found in a variety of occupational settings, including the oil, paper, plastics, and pesticides industries. It is a toxic gas and deaths from methyl mercaptan exposure have occurred. The Department of Homeland Security considers it a high threat chemical agent that could be used by terrorists. Unfortunately, no specific treatment exists for methyl mercaptan poisoning. METHODS: We conducted a randomized trial in 12 swine comparing no treatment to intramuscular injection of the vitamin B12 analog cobinamide (2.0 mL, 12.5 mg/kg) following acute inhalation of methyl mercaptan gas. Physiological and laboratory parameters were similar in the control and cobinamide-treated groups at baseline and at the time of treatment. RESULTS: All six cobinamide-treated animals survived, whereas only one of six control animals lived (17% survival) (p = 0.0043). The cobinamide-treated animals returned to a normal breathing pattern by 3.8 ± 1.1 min after treatment (mean ± SD), while all but one animal in the control group had intermittent gasping, never regaining a normal breathing pattern. Blood pressure and arterial oxygen saturation returned to baseline values within 15 minutes of cobinamide-treatment. Plasma lactate concentration increased progressively until death (10.93 ± 6.02 mmol [mean ± SD]) in control animals, and decreased toward baseline (3.79 ± 2.93 mmol [mean ± SD]) by the end of the experiment in cobinamide-treated animals. CONCLUSION: We conclude that intramuscular administration of cobinamide improves survival and clinical outcomes in a large animal model of acute, high dose methyl mercaptan poisoning.

Prehospital Life-Saving Interventions Performed on Pediatric Patients in a Combat Zone: A Multicenter Prospective Study.

OBJECTIVES: We aimed to describe and evaluate prehospital life-saving interventions performed in a pediatric population in the Afghanistan theater of operations. DESIGN: Our study was a post hoc, subanalysis of a larger multicenter, prospective, observational study. SETTING: We evaluated casualties enrolled upon admission to one of the nine military medical facilities in Afghanistan between January 2009 and March 2014. PATIENTS: Adult and pediatric (<17 yr old) patients. MEASUREMENTS: We conducted initial descriptive analyses followed by comparative tests. For comparative analysis, we stratified the study population (adult vs pediatric), and subsequently, we compared injury descriptions and the interventions performed. Following tests for normality, we used the t test or Wilcoxon rank-sum test (nonparametric) for continuous variables and chi-square or Fisher exact for categorical variables. We reported percentages and 95% CIs. MAIN RESULTS: We enrolled 2,106 patients, of which 5.6% (n = 118) were pediatric. Eighty-two percent of the pediatric patients were male, and 435 had blast related injuries. A total of 295 prehospital life-saving interventions were performed on 118 pediatric patients, for an average of 2.5 life-saving interventions per patient. Vascular access (IV 96%, intraosseous 91%) and hypothermia prevention-related interventions (69%) were the most common. Incorrectly performed life-saving interventions in pediatric patients were rare (98% of life-saving interventions performed correctly) and n equals to 24 life-saving interventions over the 6-year period were missed. The most common incorrectly performed and missed life-saving interventions were related to vascular access. When compared with adult life-saving interventions received in the prehospital environment, pediatric patients were more likely to receive intraosseous access (p < 0.0001), whereas adult patients were more likely to have a tourniquet placed (p = 0.0019), receive wound packing with a hemostatic agent (p = 0.0091), and receive chest interventions (p = 0.0003). CONCLUSIONS: In our study, the most common intervention was vascular access followed by hypothermia prevention and hemorrhage control. The occurrence of missed or incorrectly performed life-saving interventions were rare.

A Traumatic Pulseless Electrical Activity Model: Mortality Increases With Hypovolemia Time.

BACKGROUND: There currently are no well-defined animal models for traumatic pulseless electrical activity (PEA). Our objective was to develop a swine model of traumatic PEA that would be useful for laboratory research where mortality is an outcome of interest. In this pilot study, we hypothesized that animals that remained in PEA without intervention for a longer period would have increased mortality. MATERIALS AND METHODS: Sixteen Yorkshire swine were alternately allocated to either 5 or 10 min of traumatic PEA without intervention. After the nonintervention period, basic life support (BLS) with mechanical cardiopulmonary resuscitation was initiated and performed for 10 min followed by advanced life support (ALS) for an additional 10 min. Hemodynamic and laboratory values are reported for baseline, posthemorrhage, end of BLS, and end of ALS periods. RESULTS: Mortality in the 10-min PEA group (100%) was higher than the 5-min group (38%) (P = 0.03). Animals in the 5-min group had improved aortic diastolic blood pressure, coronary perfusion pressure, and end-tidal CO2 at the end of both the BLS (P = 0.02, 0.002, and 0.02, respectively) and ALS (P = 0.009, 0.005, and 0.008, respectively). The 10-min animals had increased hyperkalemia at the end of the BLS (P = 0.004) and ALS (P = 0.005) periods. All animals in the 10-min group developed ventricular fibrillation (VF) and 38% of the 5-min animals developed VF (P = 0.03). CONCLUSIONS: In our pilot study of traumatic PEA in a swine model, a shorter period of nonintervention resulted in increased survival, improved hemodynamics during resuscitation, decreased hyperkalemia, and less incidence of conversion to VF arrest.

A prospective, randomized trial of intravenous hydroxocobalamin versus noradrenaline or saline for treatment of lipopolysaccharide-induced hypotension in a swine model.

Early, non-clinical studies support the use of hydroxocobalamin to treat sepsis-induced hypotension, but there is no translational, large animal model. The objective of this study was to compare survival in a sepsis model where large swine had endotoxaemia induced with lipopolysaccharide (LPS) and were treated with intravenous hydroxocobalamin (HOC), noradrenaline (NA), or saline. Thirty swine (45-55 kg) were anaesthetized, intubated, and instrumented with continuous femoral and pulmonary artery pressure monitoring. Hypotension, predefined as 50% of baseline, was induced with LPS. Animals then received HOC, NA, or saline and monitored for 3 hours. The main outcome was survival to the conclusion of the study. Using a power of 80% and an alpha of 0.05, 10 animals were used per group. Secondary outcomes included: mean arterial pressure (MAP), systemic vascular resistance (SVR) and cardiac output (CO) along with several markers of sepsis. No differences were detected between groups at baseline or after hypotension. The survival distributions of the three groups were significantly different with more HOC animals surviving (10/10) compared with NA (8/10) or Saline (5/10) (log-rank P < 0.03). MAP was found to be higher in both the HOC and NA groups and HOC achieved the highest SVR. In this large animal, translational study of an endotoxaemic model of sepsis, hydroxocobalamin improved survival when compared with saline.

Trends in Prehospital Analgesia Administration by US Forces From 2007 Through 2016.

BACKGROUND: Tactical Combat Casualty Care (TCCC) guidelines regarding prehospital analgesia agents have evolved. The guidelines stopped recommending intramuscular (IM) morphine in 1996, recommending only intravenous (IV) routes. In 2006, the guidelines recommended oral transmucosal fentanyl citrate (OTFC), and in 2012 it added ketamine via all routes. It remains unclear to what extent prehospital analgesia administered on the battlefield adheres to these guidelines. We seek to describe trends in analgesia administration patterns on the battlefield during 2007-2016. METHODS: This is a secondary analysis of a Department of Defense Trauma Registry data set from January 2007 to August 2016. Within that group, we searched for subjects who received IM morphine, IV morphine, OTFC, parenteral fentanyl, or ketamine (all routes). RESULTS: Our predefined ED search codes captured 28,222 subjects during the study period. Of these, 594 (2.1%) received IM morphine; 3,765 (13.3%) received IV morphine; 589 (2.1%) received OTFC; and 1,510 (5.4%) subjects received ketamine. Annual rates of administration of IM morphine were relatively stable during the study period, while those for OTFC and ketamine generally trended upward starting in 2012. In particular, the proportion of subjects receiving ketamine rose from 3.9% (n = 995/25,618) during the study period preceding its addition to the TCCC guidelines (2007 to 2012) to 19.8% thereafter (2013-2016, n = 515/2,604, p < 0.001). CONCLUSIONS: During the study period, rates of prehospital administration of IM morphine remained relatively stable while those for OTFC and ketamine both rose. These findings suggest that TCCC guidelines recommending the use of these agents had a material impact on prehospital analgesia patterns.

Analysis of Injuries and Prehospital Interventions Sustained by Females in the Iraq and Afghanistan Combat Zones.

Background: Women served in both combat and non-combat units in the recent conflicts in Iraq and Afghanistan. Moreover, the recent conflicts lacked traditional separation of civilians from combatants carrying additional risk for injury to local civilians. There is a relative paucity of data specific to this topic. We compare injury patterns and interventions performed in the prehospital, combat setting among females versus males. Methods: This is a secondary analysis of previously published data from the Department of Defense Trauma Registry. We included all subjects that had at least one prehospital intervention documented. We compared variables between females and males. Results: From January 2007 to August 2016, our inclusion criteria captured 19,485 males and 533 females. Female casualties were older (median age 29 vs. 25), less likely to have sustained injuries from explosives (48.0% vs. 56.8%), and more severely injured as measured by median composite injury scores (10 vs. 9). Most subjects were in Afghanistan for both females and males (52.9% vs. 73.9%). Among United States (US) service members, findings were similar to the overall study population, except female service members had lower median composite injury scores than males (5 vs. 9). In unadjusted analyses, females were less likely to survive to hospital discharge (OR 0.68, 95% CI 0.48-0.97). There was no difference in survival (OR 0.73, 95% CI 0.50-1.07), when controlling for confounders. In both unadjusted and adjusted analyses specific to US forces, we were unable to detect any differences in survival or for select analgesic administration. In both unadjusted and adjusted analyses specific to host nation civilians, we were unable to detect any differences in survival; however, even when controlling for confounders females were less likely to receive ketamine and IV morphine (OR 0.31, 95% CI 0.15-0.63; 0.69, 95% CI 0.49-0.98, respectively). Conclusions: Females accounted for a small proportion of total casualties within our dataset. After controlling for confounders, survival was comparable between males and females, but host nation females were less likely to receive ketamine and intravenous morphine. Future studies should seek to elucidate the reasons for these subtle differences between males and females in prehospital combat casualty care.

An analysis of casualties presenting to military emergency departments in Iraq and Afghanistan.

BACKGROUND: During the past 17 years of conflict the deployed US military health care system has found new and innovative ways to reduce combat mortality down to the lowest case fatality rate in US history. There is currently a data dearth of emergency department (ED) care delivered in this setting. We seek to describe ED interventions in this setting. METHODS: We used a series of ED procedure codes to identify subjects within the Department of Defense Trauma Registry from January 2007 to August 2016. RESULTS: During this time, 28,222 met inclusion criteria. The median age of causalities in this dataset was 25 years and most (96.9%) were male, US military (41.3%), and part of Operation Enduring Freedom (66.9%). The majority survived to hospital discharge (95.5%). Most subjects sustained injuries by explosives (55.3%) and gunshot wound (GSW). The majority of subjects had an injury severity score that was considered minor (74.1%), while the preponderance of critically injured casualties sustained injuries by explosive (0.7%). Based on AIS, the most frequently seriously injured body region was the extremities (23.9%). The bulk of administered blood products were packed red blood cells (PRBC, 26.4%). Endotracheal intubation was the most commonly performed critical procedure (11.9%). X-ray (79.9%) was the most frequently performed imaging study. CONCLUSIONS: US military personnel comprised the largest proportion of combat casualties and most were injured by explosive. Within this dataset, ED providers most frequently performed endotracheal intubation, administered blood products, and obtained diagnostic imaging studies.

Prehospital ketamine administration to pediatric trauma patients with head injuries in combat theaters.

BACKGROUND: Head injuries frequently occur in combat. Tactical Combat Casualty Care (TCCC) guidelines recommend pre-hospital use of ketamine for analgesia. Yet the use of this medication in patients with head injuries remains controversial, particularly among pediatric patients. We compare survival to hospital discharge rates among pediatric head injury subjects who received prehospital ketamine versus those who did not. METHODS: We queried the Department of Defense Trauma Registry (DODTR) for all pediatric (<18 years of age) subjects from January 2007 to January 2016. We performed a sub-analysis of subjects with an abbreviated injury severity score for the head of 3 (serious) or higher and at least one documented Glasgow Coma Score (GCS) ≤13. RESULTS: Of the 3439 pediatric patients within our dataset, 555 subjects met inclusion criteria for head injury - 36 (6.5%) received prehospital ketamine versus 519 (93.5%) who did not. There was no significant difference noted between groups regarding median age (10 versus 8, p = 0.259), percent male gender (72.2% versus 76.3%, p = 0.579), mechanism of injury (p = 0.143), median composite injury scores (22 versus 20, p = 0.082), median ventilator-free days (28 versus 27, p = 0.068), median ICU-free days (27.5 versus 27, p = 0.767), median hospital days (3.5 versus 4, p = 0.876) or survival to discharge (66.7% versus 70.7%, p = 0.607). CONCLUSIONS: Within this data set, we were unable to detect any differences in mortality among pediatric head trauma subjects administered ketamine compared to subjects not receiving this medication in the prehospital setting.

An Analysis of Adherence to Tactical Combat Casualty Care Guidelines for the Administration of Tranexamic Acid.

BACKGROUND: Hemorrhage is the leading cause of potentially survivable deaths in combat. Previous research demonstrated that tranexamic acid (TXA) administration decreased mortality among casualties. For casualties expected to receive a transfusion, the Committee on Tactical Combat Casualty Care (TCCC) recommends TXA. Despite this, the use and adherence of TXA in the military prehospital combat setting, in accordance with TCCC guidelines, is low. OBJECTIVES: We sought to analyze TXA administration and use among combat casualties reasonably expected to require blood transfusion, casualties with tourniquet placement, amputations, and gunshot wounds. METHODS: Based on TCCC guidelines, we measured proportions of patients receiving prehospital TXA: casualties undergoing tourniquet placement, casualties sustaining amputation proximal to the phalanges, patients sustaining gunshot wounds, and patients receiving ≥10 units of blood products within 24 h of injury. Univariable and multivariable analyses were also completed. RESULTS: Within our dataset, 255 subjects received TXA. Four thousand seventy-one subjects had a tourniquet placed, of whom 135 (3.3%) received prehospital TXA; 1899 subjects had an amputation proximal to the digit with 106 (5.6%) receiving prehospital TXA; and 6660 subjects had a gunshot wound with 88 (1.3%) receiving prehospital TXA. Of 4246 subjects who received ≥10 units of blood products within the first 24 h, 177 (4.2%) received prehospital TXA. CONCLUSIONS: We identified low TXA administration despite TCCC recommendations. Future studies should seek to both identify reasons for limited TXA administration and methods to increase future utilization.

Comparison of zone 3 Resuscitative Endovascular Balloon Occlusion of the Aorta and the Abdominal Aortic and Junctional Tourniquet in a model of junctional hemorrhage in swine.

BACKGROUND: Traumatic injuries to the pelvis and high junctional injuries are difficult to treat in the field; however, Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) and the Abdominal Aortic and Junctional Tourniquet (AAJT) constitute two promising treatment modalities. The aim of this study is to use a large animal model of pelvic hemorrhage to compare the survival, hemostatic, hemodynamic, and metabolic profile of both techniques. METHODS: Yorkshire swine (n = 10, 70-90 kg) underwent general anesthesia, instrumentation, and surgical isolation of the femoral artery. Uncontrolled hemorrhage was initiated by an arteriotomy. Animals were randomly allocated to either REBOA or AAJT. Following completion of device application, both groups received a 500 mL Hextend bolus. After 1 hour, the injured femoral artery was ligated to simulate definitive hemostasis followed by a second Hextend bolus and device removal. Animals were observed for two more hours. Physiological data were collected throughout the experiments and compared between groups. RESULTS: Both techniques achieved 100% hemostasis, and all animals survived the entire experiment except one in the REBOA group. During the hour treatment phase, the AAJT group had a higher mean arterial pressure than the REBOA group (59.9 ± 16.1 versus 44.6 ± 9.8 mm Hg, respectively; P < 0.05). The AAJT-treated group had higher lactate levels than the REBOA-treated group (4.5 ± 2.0 versus 3.2 ± 1.3 mg/dL, respectively; P < 0.05). CONCLUSIONS: Despite their mechanistic differences, both techniques achieved a similar hemostatic, hemodynamic, and metabolic profile. Some differences do exist including lactate levels and blood pressure.

Emergency Department Intubation Success With Succinylcholine Versus Rocuronium: A National Emergency Airway Registry Study.

STUDY OBJECTIVE: Although both succinylcholine and rocuronium are used to facilitate emergency department (ED) rapid sequence intubation, the difference in intubation success rate between them is unknown. We compare first-pass intubation success between ED rapid sequence intubation facilitated by succinylcholine versus rocuronium. METHODS: We analyzed prospectively collected data from the National Emergency Airway Registry, a multicenter registry collecting data on all intubations performed in 22 EDs. We included intubations of patients older than 14 years who received succinylcholine or rocuronium during 2016. We compared the first-pass intubation success between patients receiving succinylcholine and those receiving rocuronium. We also compared the incidence of adverse events (cardiac arrest, dental trauma, direct airway injury, dysrhythmias, epistaxis, esophageal intubation, hypotension, hypoxia, iatrogenic bleeding, laryngoscope failure, laryngospasm, lip laceration, main-stem bronchus intubation, malignant hyperthermia, medication error, pharyngeal laceration, pneumothorax, endotracheal tube cuff failure, and vomiting). We conducted subgroup analyses stratified by paralytic weight-based dose. RESULTS: There were 2,275 rapid sequence intubations facilitated by succinylcholine and 1,800 by rocuronium. Patients receiving succinylcholine were younger and more likely to undergo intubation with video laryngoscopy and by more experienced providers. First-pass intubation success rate was 87.0% with succinylcholine versus 87.5% with rocuronium (adjusted odds ratio 0.9; 95% confidence interval 0.6 to 1.3). The incidence of any adverse event was also comparable between these agents: 14.7% for succinylcholine versus 14.8% for rocuronium (adjusted odds ratio 1.1; 95% confidence interval 0.9 to 1.3). We observed similar results when they were stratified by paralytic weight-based dose. CONCLUSION: In this large observational series, we did not detect an association between paralytic choice and first-pass rapid sequence intubation success or peri-intubation adverse events.