Descriptive Analysis of Combat-Associated Aspiration Pneumonia.

BACKGROUND: Airway obstruction is the second leading cause of potentially preventable death on the battlefield. The treatment for airway obstruction is intubation or advanced airway adjunct, which has a known risk of aspiration. We sought to describe the variables associated with aspiration pneumonia after prehospital airway intervention. METHODS: This is a sub-analysis of previously described data from the Department of Defense Trauma Registry (DoDTR) from 2007 to 2020. We included casualties that had at least one prehospital airway intervention with documentation of subsequent aspiration pneumonia or pneumonia within three days of the intervention. We used a generalized linear model with Firth bias estimates to test for associations. RESULTS: There were 1,509 casualties that underwent prehospital airway device placement. Of these, 41 (2.7%) met inclusion criteria into the aspiration pneumonia cohort. The demographics had no statistical difference between the groups. The non-aspiration cohort had fewer median ventilator days (2 versus 6, p < 0.001), intensive care unit days (2 versus 7, p < 0.001, and hospital days [3 versus 8, p < 0.001]). Survival was lower in the non-aspiration cohort (74.2% versus 90.2%, p = 0.017). The administration of succinylcholine was higher in the non-aspiration cohort (28.0% versus 12.2%, p = 0.031). In our multivariable model, only the administration of succinylcholine was significant and was associated with lower probability of aspiration pneumonia (odds ratio 0.56). CONCLUSION: Overall, the incidence of aspiration pneumonia was low in our cohort. The administration of succinylcholine was associated with a lower odds of developing aspiration pneumonia.

CAN POLYETHYLENE GLYCOL-20K REPLACE ALBUMIN FOR PREHOSPITAL TREATMENT OF HEMORRHAGIC SHOCK WHEN FULL RESUSCITATION IS UNAVAILABLE?

ABSTRACT: A solution of high concentration albumin has been used for temporal volume expansion when timely resuscitation was unavailable after hemorrhagic shock. However, during prolonged hemorrhagic shock, cell edema and interstitial dehydration can occur and impede the volume expansion effect of albumin. Polyethylene glycol-20K (PEG) can establish an osmotic gradient from swollen cells to capillary lumens and thus facilitate capillary fluid shift and volume expansion. We hypothesized that with similar osmolality, 7.5% PEG elicits more rapid and profound compensatory responses after hemorrhagic shock than 25% albumin. Rats were randomized into three groups (n = 8/group) based on treatment: saline (vehicle), PEG (7.5%), and albumin (25%). Trauma was induced in anesthetized rats with muscle injury and fibula fracture, followed by pressure-controlled hemorrhagic shock (MAP = 55 mm Hg) for 45 min. Animals then received an intravenous injection (0.3 mL/kg) of saline, PEG, or albumin. MAP, heart rate, blood gases, hematocrit, skeletal muscle capillary flow, renal blood flow, glomerular filtration rate, urinary flow, urinary sodium concentration, and mortality were monitored for another 2 hours. Polyethylene glycol-20K and albumin both improved MAP, renal and capillary blood flow, and renal oxygen delivery, and decreased hyperkalemia, hyperlactatemia, hematocrit, and mortality (saline: 100% PEG: 12.5%; albumin: 38%) over saline treatment. Compared with albumin, PEG had a more rapid decrease in hematocrit and more profound increases in MAP, diastolic pressure, renal blood flow, glomerular filtration rate, and urinary flow. These results suggest that PEG may be a better option than albumin for prolonged prehospital care of hemorrhagic shock.

Improving Outcomes Associated with Prehospital Combat Airway Interventions: An Unrealized Opportunity.

BACKGROUND: Airway obstruction is the second leading cause of potentially survivable death on the battlefield. Assessing outcomes associated with airway interventions is important, and temporal trends can reflect the influence of training, technology, the system of care, and other factors. We assessed mortality among casualties undergoing prehospital airway intervention occurring over the course of combat operations during 2007-2019. METHODS: This is a retrospective analysis of a previously described dataset from the Department of Defense Trauma Registry (DODTR). We included only casualties with documented placement of an endotracheal tube, cricothyrotomy, or supraglottic airway (SGA) in the prehospital setting. RESULTS: Within the DODTR from January 2007 to December 2019, there were 25,849 adult encounters with documentation of any prehospital activity. Within that group, there were 251 documented cricothyrotomies, 1,147 documented intubations, and 35 documented supraglottic airways placed. Cricothyrotomy recipients had a median age of 25. Within this group, the largest proportion were non-North Atlantic Treaty Organization (NATO) military personnel (35%), were injured by explosives (54%), had a median injury severity score (ISS) of 24, and 60% survived to hospital discharge. Intubation recipients had a median age of 24. Within this group, the largest proportion were non-NATO military personnel (37%), were injured by explosives (57%), had a median ISS of 18, and 76% survived to hospital discharge. SGA recipients had a median age of 28. Within this group, the largest proportion were non-NATO military (37%), were injured by firearms (48%), had a median ISS of 25, and 54% survived to hospital discharge. A downward trend existed in the quantity of all procedures performed during the study period. In both unadjusted and adjusted regression models, we identified no year-to-year differences in survival after prehospital cricothyrotomy or SGA placement. In the unadjusted and adjusted models, we noted a decrease in mortality during the 2007-2008 (odds ratio [OR] for death 0.47, 95% CI 0.26-0.86) and an increase from 2012-2013 (OR 2.10, 95% CI 1.09-4.05) for prehospital intubation. CONCLUSION: Mortality among combat casualties undergoing prehospital or emergency department airway interventions showed no sustained change during the study period. These findings suggest that advances in airway resuscitation are necessary to achieve mortality improvements in potentially survivable airway injuries in the prehospital setting.

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.

A mixed methods end-user assessment to determine the ideal supraglottic airway device for inclusion into the medic's aid bag.

BACKGROUND: Many advancements in supraglottic airway technology have occurred since the start of the Global War on Terrorism. While the Tactical Combat Casualty Care guidelines previously recommend the i-gel device, this is based on little data and minimal end-user input. OBJECTIVE: We sought to use a mixed methods approach to investigate the properties of an ideal device for inclusion into the medic's aid bag. METHODS: We performed prospective, serial qualitative studies to uncover and articulate themes relative to airway device usability with 68W-combat medics. 68W are trained roughly to the level of a civilian advanced emergency medical technician with a heavier focus on trauma care. Physicians with airway expertise demonstrated the use of each device and provided formal training on all the presented devices. We then administered performed focus groups to solicit end-user feedback along with survey data. RESULTS: We enrolled 250 medics during the study. The preponderance of medics were of the rank E4 (28%) and E5 (44%). Only 35% reported ever placing a supraglottic airway in a real human. When reporting on usability, the i-gel had the highest median score, ease of manipulation, grip comfort and ease of insertion while also scoring the best in regard to requiring minimal training. The other compared devices had no clear highest score. Qualitative data saturated around a strong preference for the BaskaMask and/or the i-gel airway device, with the least favorite being the AirQ and the LMA Fastrach airway devises. There was a strong qualitative alignment in how both the BaskaMask and i-gel provided ease of use and simplicity of training. CONCLUSION: There were strong qualitative preferences for two specific airway devices: Baska Mask and i-gel. However, many medics commented on their previous experience with the i-gel compared with the other devices, which may have biased them toward the i-gel. The overall data suggest that medics would prefer a device engineered with features from several devices. LEVEL OF EVIDENCE: Therapeutic/care management; Level V.

Pathophysiology of Hemorrhage as It Relates to the Warfighter.

Saving lives of wounded military warfighters often depends on the ability to resolve or mitigate the pathophysiology of hemorrhage, specifically diminished oxygen delivery to vital organs that leads to multiorgan failure and death. However, caring for hemorrhaging patients on the battlefield presents unique challenges that extend beyond applying a tourniquet and giving a blood transfusion, especially when battlefield care must be provided for a prolonged period. This review describes these challenges and potential strategies for treating hemorrhage on the battlefield in a prolonged casualty care situation.

Changes in Emergency Department Volumes at the Largest U.S. Military Hospital During the COVID-19 Pandemic.

INTRODUCTION: The coronavirus-2019 (COVID-19) pandemic has significantly impacted global healthcare delivery. Brooke Army Medical Center (BAMC) is the DoD's largest hospital and a critical platform for maintaining a ready medical force. We compare temporal trends in patient volumes and characteristics in the BAMC emergency department (ED) before versus during the pandemic. MATERIALS AND METHODS: We abstracted data on patient visits from the BAMC ED electronic medical record system. Data included patient demographics, visit dates, emergency severity index triage level, and disposition. We visually compared the data from January 1, 2019 to November 30, 2019 versus January 1, 2020 to November 30, 2020 to assess the period with the most apparent differences. We then used descriptive statistics to characterize the pre-pandemic control period (1 March-November 30, 2019) versus the pandemic period (1 March-November 30, 2020). RESULTS: Overall, when comparing the pre-pandemic and pandemic periods, the median number of visits per day was 232 (Interquartile Range (IQR) 214-250, range 145-293) versus 165 (144-193, range 89-308, P < .0001). Specific to pediatric visits, we found the median number of visits per day was 39 (IQR 33-46, range 15-72) versus 18 (IQR 14-22, range 5-61, P < .001). When comparing the median number of visits by month, the volumes were lower during the pandemic for all months, all of which were strongly significant (P < .001 for all). CONCLUSIONS: The BAMC ED experienced a significant decrease in patient volume during the COVID-19 pandemic starting in March 2020. This may have significant implications for the capacity of this facility to maintain a medically ready force.

Battlefield Vital Sign Monitoring in Role 1 Military Treatment Facilities: A Thematic Analysis of After-Action Reviews from the Prehospital Trauma Registry.

INTRODUCTION: The Prehospital Trauma Registry (PHTR) captures after-action reviews (AARs) as part of a continuous performance improvement cycle and to provide commanders real-time feedback of Role 1 care. We have previously described overall challenges noted within the AARs. We now performed a focused assessment of challenges with regard to hemodynamic monitoring to improve casualty monitoring systems. MATERIALS AND METHODS: We performed a review of AARs within the PHTR in Afghanistan from January 2013 to September 2014 as previously described. In this analysis, we focus on AARs specific to challenges with hemodynamic monitoring of combat casualties. RESULTS: Of the 705 PHTR casualties, 592 had available AAR data; 86 of those described challenges with hemodynamic monitoring. Most were identified as male (97%) and having sustained battle injuries (93%), typically from an explosion (48%). Most were urgent evacuation status (85%) and had a medical officer in their chain of care (65%). The most common vital sign mentioned in AAR comments was blood pressure (62%), and nearly one-quarter of comments stated that arterial palpation was used in place of blood pressure cuff measurements. CONCLUSIONS: Our qualitative methods study highlights the challenges with obtaining vital signs-both training and equipment. We also highlight the challenges regarding ongoing monitoring to prevent hemodynamic collapse in severely injured casualties. The U.S. military needs to develop better methods for casualty monitoring for the subset of casualties that are critically injured.

A Prospective, Feasibility Assessment of a Novel, Disposable Video Laryngoscope With Special Operations Medical Personnel in a Mobile Helicopter Simulation Setting.

BACKGROUND: Video laryngoscopy (VL) is shown to improve first-pass success rates and decrease complications in intubations, especially in novice proceduralists. However, the currently fielded VL devices are cost-prohibitive for dispersion across the battlespace. The novel i-view VL is a low-cost, disposable VL device that may serve as a potential solution. We sought to perform end-user performance testing and solicit feedback. METHODS: We prospectively enrolled Special Operations flight medics with the 160th Special Operations Aviation Regiment at Hunter Army Airfield, Savannah, Georgia. We asked them to perform an intubation using a synthetic cadaver model while in a mobile helicopter simulation setting. We surveyed their feedback afterward. RESULTS: The median age of participants was 30 and all were male. Of those, 60% reported previous combat deployments, with a median of 20 months of deployment time. Of the 10, 90% were successful with intubation, with 60% on first-pass success with an average of 83 seconds time to intubation. Most had a grade 1 view. Most agreed or strongly agreed that it was easy to use (70%), with half (50%) reporting they would use it in the deployed setting. Several made comments about the screen not being bright enough and would prefer one with a rotating display. CONCLUSIONS: We found a high proportion of success for intubation in the mobile simulator and a high satisfaction rate for this device by Special Operations Forces medics.

Analysis of the Effects of COVID-19 Mask Mandates on Hospital Resource Consumption and Mortality at the County Level.

OBJECTIVES: Coronavirus disease 2019 (COVID-19) threatens vulnerable patient populations, resulting in immense pressures at the local, regional, national, and international levels to contain the virus. Laboratory-based studies demonstrate that masks may offer benefit in reducing the spread of droplet-based illnesses, but few data are available to assess mask effects via executive order on a population basis. We assess the effects of a county-wide mask order on per-population mortality, intensive care unit (ICU) utilization, and ventilator utilization in Bexar County, Texas. METHODS: We used publicly reported county-level data to perform a mixed-methods before-and-after analysis along with other sources of public data for analyses of covariance. We used a least-squares regression analysis to adjust for confounders. A Texas state-level mask order was issued on July 3, 2020, followed by a Bexar County-level order on July 15, 2020. We defined the control period as June 2 to July 2 and the postmask order period as July 8, 2020-August 12, 2020, with a 5-day gap to account for the median incubation period for cases; longer periods of 7 and 10 days were used for hospitalization and ICU admission/death, respectively. Data are reported on a per-100,000 population basis using respective US Census Bureau-reported populations. RESULTS: From June 2, 2020 through August 12, 2020, there were 40,771 reported cases of COVID-19 within Bexar County, with 470 total deaths. The average number of new cases per day within the county was 565.4 (95% confidence interval [CI] 394.6-736.2). The average number of positive hospitalized patients was 754.1 (95% CI 657.2-851.0), in the ICU was 273.1 (95% CI 238.2-308.0), and on a ventilator was 170.5 (95% CI 146.4-194.6). The average deaths per day was 6.5 (95% CI 4.4-8.6). All of the measured outcomes were higher on average in the postmask period as were covariables included in the adjusted model. When adjusting for traffic activity, total statewide caseload, public health complaints, and mean temperature, the daily caseload, hospital bed occupancy, ICU bed occupancy, ventilator occupancy, and daily mortality remained higher in the postmask period. CONCLUSIONS: There was no reduction in per-population daily mortality, hospital bed, ICU bed, or ventilator occupancy of COVID-19-positive patients attributable to the implementation of a mask-wearing mandate.

An Assessment of Combat Medic Supraglottic Airway Device Design Needs Using a Qualitative Methods Approach: A Preliminary Analysis.

INTRODUCTION: Airway obstruction is the second leading cause of potentially preventable death on the battlefield during the recent conflicts. Previous studies have noted challenges with enrolling medics using quantitative methods, with specific challenges related to limited prior experience with the devices presented. This limited the ability to truly assess the efficacy of a particular device. We sought to implement a qualitative methods design for supraglottic airway (SGA) device testing. METHODS: We performed prospective, qualitative-designed studies in serial to discover emerging themes on interview. We obtained consent and demographic information from all participants. Medics were presented 2-3 airway devices in the same session with formal training by a physician with airway expertise to include practice application and troubleshooting. Semi-structured interviews were used after the training to obtain end-user feedback with a focus on emerging themes. RESULTS: Of the 77 medics surveyed and interviewed, the median age was 24, and 86% were male. During the interview sessions, we noted five emerging themes: (1) insertion, which pertains to the ease or complexity of using the devise; (2) material, which pertains to the tactile features of the device; (3) versatility, which pertains to the conditions in which the device can be used as well as with which other devices it can be used; (4) portability, which refers to how and where the device is stored and carried; and (5) training, which refers to the ease and frequency of initial and ongoing training to sustain medics' technical capability when using the device. CONCLUSIONS: In our preliminary analysis after enrolling 77 medics, we noted 5 emerging themes focused on insertion material, versatility, portability, and training methodology. Our results will inform the future enrollment sessions with a goal of narrowing the market options from themes to ideal device or devices or modifications needed for the operational environment.

Innovative Solution for Airway Securement in Combat and Trauma Scenarios.

Airway management is one of the most challenging problems in prehospital combat casualty care. Airway assessment and intervention are second only to hemorrhage control in priority in the initial treatment of trauma patients, and airway compromise continues to account for approximately 1 in 10 preventable battlefield deaths. Combat medics often provide care in no- or low-light conditions, surrounded by the chaos of combat, and with the limited dexterity that accompanies bulky body armor, gloves, and heavy equipment. Far-forward medical care is also limited by available resources, which are often only what a combat medic can fit in the aid bag. Therefore, a procedure such as airway management that currently requires a high degree of skill becomes substantially more complex. Improved airway devices are listed among the top five in a comprehensive list of battlefield research and development priorities by the Defense Health Board, yet the challenge of airway management has received little investment compared to other causes of preventable battlefield death such as exsanguinating hemorrhage and traumatic brain injury.

An Analysis of Prehospital Trauma Registry: After-Action Reviews on Airway Interventions in Afghanistan

BACKGROUND: Failed airway management is the second leading cause of preventable death on the battlefield. The prehospital trauma registry (PHTR) after action-review (AAR) allows for unique perspectives and an enhanced analysis of interventions performed. We analyzed AAR comments related to airway interventions performed in deployed settings to examine and identify trends in challenges related to airway management in combat. DESIGN AND METHODS: We analyzed all AAR comments included for airway interventions reported in the Joint Trauma System PHTR. We applied unstructured qualitative methods to analyze themes within these reports and generated descriptive statistics to summarize findings related to airway management. RESULTS: Out of 705 total casualty encounters in the PHTR system between January 2013 and September 2014, 117 (16.6%) had a documented airway intervention. From this sample, 17 (14.5%) had accompanying AAR comments for review. Most patients were identified as host nation casualties (94%, n =16), male (88%, n = 15), and prioritized as urgent evacuation (100%, n = 17). Twenty-five airway interventions were described in the AAR comments, the most being endotracheal intubation (52%, n = 13), followed by ventilation management (28%, n = 7), and cricothyroidotomy (12%, n = 3). Comments indicated difficulties with surgical procedures and suboptimal anatomy identification. CONCLUSIONS: AAR comments focused primarily on cricothyroidotomy, endotracheal intubation, and ventilation management, citing needs for improvement in technique and anatomy identification. Future efforts should focus on training methods for these interventions and increased emphasis on AAR completion.

Extremity trauma exacerbates acute kidney injury following prolonged hemorrhagic hypotension.

BACKGROUND: The incidence of and mortality due to acute kidney injury is high in patients with traumatic shock. However, it is unclear how hemorrhage and trauma synergistically affect renal function, especially when timely volume resuscitation is not available. METHOD: We hypothesized that trauma impairs renal tolerance to prolonged hemorrhagic hypotension. Sprague-Dawley rats were randomized into six groups: control, extremity trauma (ET), hemorrhage at 70 mm Hg (70-H), hemorrhage at 55 mm Hg (55-H), ET + 70 mm Hg (70-ETH), and ET + 55 mm Hg (55-ETH). Animals were anesthetized, and ET was induced via soft tissue injury and closed fibula fracture. Hemorrhage was performed via catheters 5 minutes after ET with target mean arterial pressure (MAP) clamped at 70 mm Hg or 55 mm Hg for up to 3 hours. Blood and urine samples were collected to analyze plasma creatinine (Cr), Cr clearance (CCr), renal oxygen delivery (DO2), urinary albumin, and kidney injury molecule-1 (KIM-1). RESULTS: Extremity trauma alone did not alter renal hemodynamics, DO2, or function. In 70-H, CCr was increased following hemorrhage, while Cr, renal vascular resistance (RVR), KIM-1, and albumin levels remained unchanged. Compared with 70-H, ET + 70 mm Hg exhibited increases in Cr and RVR with decreases in CCr and DO2. In addition, ET decreased the blood volume loss required to maintain MAP = 70 mm Hg by approximately 50%. Hemorrhage at 55 mm Hg and ET + 55 mm Hg exhibited a marked and similar decrease in CCr and increases in RVR, Cr, KIM-1, and albumin. However, ET greatly decreased the blood volume loss required to maintain MAP at 55 mm Hg and led to 50% mortality. CONCLUSION: These results suggest that ET impairs renal and systemic tolerance to prolonged hemorrhagic hypotension. Thus, traumatic injury should be considered as a critical component of experimental studies investigating outcomes and treatment following hemorrhagic shock. LEVEL OF EVIDENCE: This is an original article on basic science and does not require a level of evidence.

Acute overventilation does not cause lung damage in moderately hemorrhaged swine.

Airway management is important in trauma and critically ill patients. Prolonged mechanical ventilation results in overventilation-induced lung barotrauma, but few studies have examined the consequence of acute (1 h or less) overventilation. We hypothesized that acute hyperventilation, as might inadvertently be performed in prehospital settings, would elevate systemic inflammation and cause lung damage. Female Yorkshire pigs (40-50 kg, n = 10/group) were anesthetized, instrumented for hemodynamic measurements and blood sampling, and underwent a 25% controlled hemorrhage followed by 1 h of 1) spontaneous breathing, 2) "normal" bag ventilation (4.8 L·min volume, ∼400 mL tidal volume, 12 breaths/minute), 3) bag hyperventilation (9 L·min volume, ∼750 mL tidal volume, 12 breaths/minute), 4) maximum hyperventilation (15 L·min volume, ∼750 mL tidal volume, 20 breaths/minute), or 5) mechanical ventilation. Pigs then regained consciousness and recovered for 24 h, followed by euthanasia and collection of blood and tissue samples. No level of manual ventilation had any significant impact on hemodynamic variables. Blood markers of tissue damage and plasma cytokines were not statistically different between groups with the exception of a transient increase in IL-1ß; all values returned to baseline by 24 h. On pathological review, severity and distribution of lung edema or other gross pathologies were not significantly different between groups. These data indicate hyperventilation causes no adverse effects, to include inflammation and tissue damage, and that acute overventilation, as could be seen in the prehospital phase of trauma care, does not produce evidence of adverse effects on the lungs following moderate hemorrhage.NEW & NOTEWORTHY Appropriate airway management is essential in trauma and critically ill patients. Prolonged mechanical ventilation can result in overventilation-induced lung barotrauma, but few studies have examined the consequence of acute overventilation. We investigated the outcome of hemorrhage followed by 1 h of overventilation in swine. We found that acute overventilation, as could be seen in the prehospital phase of trauma care, does not produce evidence of adverse effects on otherwise healthy lungs following moderate hemorrhage.

A Comparison of the iGel Versus Cricothyrotomy by Combat Medics Using a Synthetic Cadaver Model: A Randomized, Controlled Pilot study.

Background: Airway obstruction is the second leading cause of potentially preventable death on the battlefield. Prior to 2017, the Committee on Tactical Combat Casualty Care (CoTCCC) recommended the surgical cricothyrotomy as the definitive airway of choice. More recently, the CoTCCC has recommended the iGel™ as the supraglottic airway (SGA) of choice. Data comparing these methods in medics are limited. We compared first-pass placement success among combat medics using a synthetic cadaver model. Methods: We conducted a randomized cross-over study of United States Army combat medics using a synthetic cadaver model. Participants performed a surgical cricothyrotomy using a method of their choosing versus placement of the SGA iGel in random order. The primary outcome was first-pass success. Secondary outcomes included time-to-placement, complications, placement failures, and self-reported participant preferences. Results: Of the 68 medics recruited, 63 had sufficient data for inclusion. Most were noncommissioned officers in rank (54%, E6-E7), with 51% reporting previous deployment experience. There was no significant difference in first-pass success (P = .847) or successful cannulation with regard to the two devices. Time-to-placement was faster with the iGel (21.8 seconds vs. 63.8 seconds). Of the 59 medics who finished the survey, we found that 35 (59%) preferred the iGel and 24 (41%) preferred the cricothyrotomy. Conclusions: In our study of active duty Army combat medics, we found no significant difference with regard to first-pass success or overall successful placement between the iGel and cricothyrotomy. Time-to-placement was significantly lower with the iGel. Participants reported preferring the iGel versus the cricothyrotomy on survey. Further research is needed, as limitations in our study highlighted many shortcomings in airway research involving combat medics.

Analysis of Casualties That Underwent Airway Management Before Reaching Role 2 Facilities in the Afghanistan Conflict 2008-2014.

INTRODUCTION: Airway compromise is the second leading cause of potentially survivable death on the battlefield. The purpose of this study was to better understand wartime prehospital airway patients. MATERIALS AND METHODS: The Role 2 Database (R2D) was retrospectively reviewed for adult patients injured in Afghanistan between February 2008 and September 2014. Of primary interest were prehospital airway interventions and mortality. Prehospital combat mortality index (CMI-PH), hemodynamic interventions, injury mechanism, and demographic data were also included in various statistical analyses. RESULTS: A total of 12,780 trauma patients were recorded in the R2D of whom 890 (7.0%) received prehospital airway intervention. Airway intervention was more common in patients who ultimately died (25.3% vs. 5.6%); however, no statistical association was found in a multivariable logistic regression model (OR 1.28, 95% CI 0.98-1.68). Compared with U.S. military personnel, other military patients were more likely to receive airway intervention after adjusting for CMI-PH (OR 1.33, 95% CI 1.07-1.64). CONCLUSIONS: In the R2D, airway intervention was associated with increased odds of mortality, although this was not statistically significant. Other patients had higher odds of undergoing an airway intervention than U.S. military. Awareness of these findings will facilitate training and equipment for future management of prehospital/prolonged field care airway interventions.

Indices of muscle and liver dysfunction after surviving hemorrhage and prolonged hypotension.

BACKGROUND: This study determined the long-term effects of prolonged hypotension (PH) on liver, muscle, and kidney dysfunction. The hypothesis was that longer duration of PH after hemorrhage will result in greater organ dysfunction. METHODS: Baboons were sedated and hemorrhaged (30% blood volume). Systolic blood pressure greater than 80 mm Hg was maintained for 1 hour (1 hr-PH; n = 5), 2 hours (2 hr-PH; n = 5), or 3 hours (3 hr-PH; n = 5). After PH, hemorrhage volume was replaced. Animals were recovered and monitored for 21 days. Control animals were hemorrhaged and immediately resuscitated (0 hr-PH, n = 3). Data are Mean ± Standard Deviation, and analyzed by 2-way repeated measures ANOVA and Holm-Sidak test. RESULTS: Hemorrhage resulted in mild hypotension. Minimal resuscitation was required during the hypotensive phase, and survival rate was 100%. Significant increases (p < 0.001) in alanine aminotransferase, aspartate aminotransferase, creatine phosphokinase, and lactate dehydrogenase occurred on Day 1 after PH, and were significantly greater (p < 0.001) in the 2 hr- and 3 hr-PH groups than the 0 hr-PH group. Maximum alanine aminotransferase levels (U/L) were 140 ± 56 (0 hr-PH), 170 ± 130 (1 hr-PH), 322 ± 241 (2 hr-PH), and 387 ± 167 (3 hr-PH). Maximum aspartate aminotransferase levels (U/L) were 218 ± 44 (0 hr-PH), 354 ± 219 (1 hr-PH), 515 ± 424 (2 hr-PH), and 711 ± 278 (3 hr-PH). Maximum creatine phosphokinase values (U/L) were 7834 ± 3681 (0 hr-PH), 24336 ± 22268 (1 hr-PH), 50494 ± 67653 (2 hr-PH), and 59857 ± 32408 (3 hr-PH). Maximum lactic acid dehydrogenase values (U/L) were 890 ± 396 (0 hr-PH), 2055 ± 1520 (1 hr-PH), 3992 ± 4895 (2 hr-PH), and 4771 ± 1884 (3 hr-PH). Plasma creatinine and blood urea nitrogen were unaffected by PH (p > 0.10). CONCLUSION: These results indicate that PH up to 3 hours in duration results in transient liver and muscle dysfunction that was most severe after 2 hr-PH and 3 hr-PH. Prolonged hypotension produced minimal effects on the kidney. LEVEL OF EVIDENCE: Basic science research, Level of evidence not required for basic science research.

Injuries Sustained During Modern Army Combatives Tournaments.

INTRODUCTION: Injuries sustained during Modern Army Combatives (MAC) tournaments can result in variable recovery time for involved competitors and unpredictable loss of readiness for military units. A paucity of MAC data is available to guide military medical providers and unit commanders on expected injuries or loss of readiness. Literature reviewing mixed martial arts competitions offers some insight but demonstrates variation in fight outcomes resulting in injuries ranging from 8.5% to 70% and it is difficult to effectively extrapolate such data to predict MAC tournament injuries. MATERIALS AND METHODS: This study retrospectively reviews pre- and post-competition medical records from two MAC tournaments held at Fort Hood in 2014 and 2015 to provide descriptive clinical information on injury patterns to practitioners and military commanders. RESULTS: Records from a total of 195 competitors with a mean age of 24.4 yr were analyzed with a total of 67 injuries, 29 of which resulted in duty limitations (14.8% of participants). Competitors participating in less-restrictive mixed martial arts style fighting (Advanced MAC) were 4.3 times more likely to sustain an injury than those limited to upper body grappling events (95% confidence interval 2.30-8.16). Military Acute Concussion Evaluations were reliably recorded both pre- and post-competition in 44% of total participants with no significant statistical difference between pre- and post-tournament evaluations. Duty profile limitations of injured competitors averaged 1 mo in duration. CONCLUSIONS: MAC tournaments result in injury rates comparable with other combative sports and military training courses.