Expert Consensus Panel Recommendations for Selection of the Optimal Supraglottic Airway Device for Inclusion to the Medic's Aid Bag

INTRODUCTION

Airway obstruction is the second leading cause of potentially survivable death on the battlefield. The Committee on Tactical Combat Casualty Care (CoTCCC) has evolving recommendations for the optimal supraglottic airway (SGA) device for inclusion to the medics' aid bag.

METHODS

We convened an expert consensus panel consisting of a mix of 8 prehospital specialists, emergency medicine experts, and experienced combat medics, with the intent to offer recommendations for optimal SGA selection. Prior to meeting, we independently reviewed previously published studies conducted by our study team, conducted a virtual meeting, and summarized the findings to the panel. The studies included an analysis of end-user after action reviews, a market analysis, engineering testing, and prospective feedback from combat medics. The panel members then made recommendations regarding their top 3 choices of devices including the options of military custom design. Simple descriptive statistics were used to analyze panel recommendations.

RESULTS

The preponderance (7/8, 88%) of panel members recommended the gel-cuffed SGA, followed by the self-inflating-cuff SGA (5/8, 62%) and laryngeal tube SGA (5/8, 62%). Panel members expressed concerns primarily related to the (1) devices' tolerance for the military environment, and (2) ability to effectively secure the gel-cuffed SGA and the self-inflating-cuff SGA during transport.

CONCLUSIONS

A preponderance of panel members selected the gel-cuff SGA with substantial feedback highlighting the need for military-specific customizations to support the combat environment needs.

An Assessment of Casualties Undergoing Delayed Surgical Intervention in the Combat Setting

INTRODUCTION

The US military is transitioning into a posture preparing for large-scale combat operations in which delays in evacuation may become common. It remains unclear which casualty population can have their initial surgical interventions delayed, thus reducing the evacuation demands.

METHODS

We performed a secondary analysis of a previously described dataset from the Department of Defense Trauma Registry (DODTR) focused on casualties who received prehospital care. In this, we sought to determine (1) of those who underwent operative intervention, the proportion of surgeries occurring ≥3 days post-injury, and (2) of those who underwent early versus delayed surgery, the proportions who required blood products.

RESULTS

There were 6,558 US military casualties who underwent surgical intervention-6,224 early (less than 3 days from injury) and 333 delayed (≥ 3 days from injury). The median Injury Severity Score (ISS) was higher in the early cohort (10 versus 6, p is less than 0.001). Serious injuries to the head were more common in the early cohort (12% versus 5%, p is less than 0.001), as were the thorax (13% versus 9%, p=0.041), abdomen (10% versus 5%, p=0.001), extremities (37% versus 14%, p is less than 0.001), and skin (4% versus less than 1%, p=0.001). Survival to discharge was lower in the early cohort (97% versus 100%, p is less than 0.001). Mean whole blood consumption was higher in the early cohort (0.5 versus 0 units, p is less than 0.001), as was packed red blood cells (6.3 versus 0.5, p is less than 0.001), platelets (0.9 versus 0, p is less than 0.001), and fresh frozen plasma (4.5 versus 0.2, p is less than 0.001). The administration of any units of packed red blood cells and whole blood was higher for the early cohort (37% versus 7%, p is less than 0.001), as was a ≥3 units threshold (30% versus 3%, p is less than 0.001), and ≥10 units threshold (18% versus 1%, p is less than 0.001).

CONCLUSIONS

Few combat casualties underwent delayed surgical interventions defined as ≥3 days post injury, and only a small number of casualties with delayed surgical intervention received blood products. Casualties who received early surgical intervention were more likely to have higher injury severity scores, and more likely to receive blood.

Prehospital Pharmacotherapy in Moderate and Severe Traumatic Brain Injury: A Systematic Review

BACKGROUND

Traumatic brain injury (TBI) affects civilian and military populations with high morbidity and mortality rates and devastating sequelae. As the US military shifts its operational paradigm to prepare for future large-scale combat operations, the need for prolonged casualty care is expected to intensify. Identifying efficacious prehospital TBI management strategies is therefore vital. Numerous pharmacotherapies are beneficial in the inpatient management of TBI, including beta blockers, calcium channel blockers, statins, and other agents. However, their utility in prehospital management of moderate or severe TBI is not well understood. We performed a systematic review to elucidate agents of potential prehospital benefit in moderate and severe TBI.

METHODS

We searched 6 databases from January 2000 through December 2021 without limitations in outcome metrics using a variety of search terms designed to encapsulate all studies pertaining to prehospital TBI management. We identified 2,142 unique articles, which netted 114 studies for full review. Seven studies met stringent inclusion criteria for our aims.

RESULTS

Studies meeting inclusion criteria assessed tranexamic acid (TXA) (n=6) and ethanol (n=1). Of the TXA studies, 3 were randomized controlled trials, 2 were retrospective cohort studies, 1 was a prospective cohort study, and 1 was a meta-analysis. Notably absent were papers investigating therapeutics shown to be beneficial in inpatient hospital treatment of TBI. Overall, data suggest TXA administration is potentially beneficial in moderate or severe TBI with or without intracranial hemorrhage. Severe TBI with or without penetrating trauma was associated with worse overall outcomes, regardless of TXA use.

CONCLUSION

Effective interventions for treating moderate or severe TBI are lacking. TXA is the most widely studied pharmacologic intervention and appears to offer some benefit without adverse effects in moderate TBI (with or without intracranial hemorrhage) in the pre-hospital setting despite heterogeneous results. Limitations of these studies include heterogeneity in outcome metrics, patient populations, and circumstances of TXA use. We identified a gap in the literature in translating agents with demonstrated inpatient benefit to the prehospital setting. Further investigation into these and other novel therapeutic options in the prehospital arena is crucial to improving clinical outcomes in TBI.

Lessons from the Fallen: An After-Action Review of Prehospital Casualty Data during the Global War on Terror

BACKGROUND

The US military's recent involvement in long standing conflict has caused the pioneering of many lifesaving medical advances, often made possible by data-driven research. However, future advances in battlefield medicine will likely require greater data fidelity than is currently attainable. Continuing to improve survival rates will require data which establishes the relative contributions to preventable mortality and guides future interventions. Prehospital data, particularly that from Tactical Combat Casualty Care (TCCC) Cards and TCCC After Action Reports (TCCC AARs), are notoriously inconsistent in reaching searchable databases for formal evaluation. While the military has begun incorporating more modern technology in advanced data capture over the past few years like the Air Force's Battlefield Assisted Trauma Distributed Observation Kit (BATDOK) and the Army's Medical Hands-free Unified Broadcast system (MEDHUB), more analysis weighing the advantages and disadvantages of substituting analog solutions is needed.

DISCUSSION

We propose 3 changes which may aid prehospital data capture and facilitate analysis: reexamine the current format of TCCC Cards and consider reducing the number of available datapoints to streamline completion, implement a military-wide mandate for all Role 1 providers to complete a TCCC AAR within 24 hours of a casualty event, and formalize the process of requesting de-identified data from the Armed Forces Medical Examiner System (AFMES) database.

CONCLUSION

Reflecting on the state of US military medicine after 20 years of war, an important focus is improving the way prehospital data is gathered and analyzed by the military. There are steps we can take now to enhance our capabilities.

Outcomes after Prehospital Cricothyrotomy

BACKGROUND

Prehospital surgical cricothyrotomies and complications from placement are an important and under-evaluated topic for both the military and civilian prehospital populations. This study uses the Department of Defense Trauma Registry to identify complications and the incidence of complications in prehospital combat surgical cricothyrotomies.

METHODS

A secondary analysis of previously described prehospital-based dataset from the Department of Defense Trauma Registry (DODTR) was performed. Casualties who had a prehospital cricothyrotomy performed were isolated and assessed for documented airway injuries and surgical procedures after hospital admission.

RESULTS

There were 25,8976 casualties in the original dataset, of which 251 met inclusion for this analysis. The median age was 25 and most (98%) were male. Explosives were most frequent (55%) followed by firearm (33%) mechanisms. Most were host nation partner forces (35%) and humanitarian (32%) casualties. The median injury severity score was 24. The most frequent seriously injured body region was the head/neck (61%). Most (61%) were discharged alive. Within the 251, 14% had a complication noted, most commonly requiring tracheostomy revision (5%).

CONCLUSIONS

Cricothyrotomies are rarely performed, but when they are performed and the casualty survives long enough to reach a military treatment facility with surgical capabilities, the incidence of near-term and long-term complications is high. A better understanding of outcomes associated with this procedure will enable more targeted training and technology development.

Expert Consensus Panel Recommendations for Selection of the Optimal Supraglottic Airway Device for Inclusion to the Medic's Aid Bag

INTRODUCTION

Airway obstruction is the second leading cause of potentially survivable death on the battlefield. The Committee on Tactical Combat Casualty Care (CoTCCC) has evolving recommendations for the optimal supraglottic airway (SGA) device for inclusion to the medics' aid bag.

METHODS

We convened an expert consensus panel consisting of a mix of 8 prehospital specialists, emergency medicine experts, and experienced combat medics, with the intent to offer recommendations for optimal SGA selection. Prior to meeting, we independently reviewed previously published studies conducted by our study team, conducted a virtual meeting, and summarized the findings to the panel. The studies included an analysis of end-user after action reviews, a market analysis, engineering testing, and prospective feedback from combat medics. The panel members then made recommendations regarding their top 3 choices of devices including the options of military custom design. Simple descriptive statistics were used to analyze panel recommendations.

RESULTS

The preponderance (7/8, 88%) of panel members recommended the gel-cuffed SGA, followed by the self-inflating-cuff SGA (5/8, 62%) and laryngeal tube SGA (5/8, 62%). Panel members expressed concerns primarily related to the (1) devices' tolerance for the military environment, and (2) ability to effectively secure the gel-cuffed SGA and the self-inflating-cuff SGA during transport.

CONCLUSIONS

A preponderance of panel members selected the gel-cuff SGA with substantial feedback highlighting the need for military-specific customizations to support the combat environment needs.

Massive Transfusion Thresholds Associated with Combat Casualty Mortality during Operations in Afghanistan and Iraq: Implications for Role 1 Logistical Support Chains

INTRODUCTION

Limited literature exists examining outcomes associated with alternative thresholds for massive transfusion outside of the historical definition of 10 units of packed red blood cells (PRBC) in 24 hours. This study reports the predictive accuracy of alternative thresholds for 24-hour mortality and explores implications for Role 1 care supply requirements.

METHODS

We conducted a secondary analysis of data from the Department of Defense Trauma Registry (DODTR) spanning encounters from 1 January 2007 through 17 March 2020. We included all casualties who received at least 1 unit of either PRBC or whole blood. We calculated area under the receiver operator curve (AUROC) of blood product quantity received, including both PRBC and whole blood, as a predictor for mortality within 24 hours of arrival to a military treatment facility. We identified optimal predictive thresholds per Youden's index.

RESULTS

We identified 28,950 encounters of which 2,608 (9.0%) entailed receipt of at least 1 unit of PRBC or whole blood. Most casualties sustained battle injuries (2,437, 93.4%) with explosives as the most common mechanism (1,900, 72.8%) followed by firearms (609, 23.3%). The AUROC for blood product received within 24 hours was 0.59. The optimal threshold for predicting 24-hour mortality per Youden's Index was 20 units (sensitivity of 34.9% and specificity of 78.6%). The threshold exceeding 90% sensitivity was 2 units; whereas, the threshold exceeding 90% specificity was 33 units.

CONCLUSIONS

We identified a wide range of numbers of received blood products associated with short-term mortality based upon prioritization of sensitivity or specificity. This study found only 2 units of blood product received had a 90% sensitivity for predicting 24-hour mortality, highlighting the resource mobilization challenges that confront healthcare providers during resuscitation at the Role 1.

A Comparison of Injury Patterns and Interventions among US Military Special Operations Versus Conventional Forces Combatants

BACKGROUND

Over the course of the US' Global War on Terrorism, its military has utilized both conventional and special operations forces (SOF). These entities have sustained and treated battlefield casualties in the prehospital, Role 1 setting, while also making efforts to mitigate risks to the force and pursuing improved interventions. The goal of this study is to compare outcomes and prehospital medical interventions between SOF and conventional military combat casualties.

METHODS

This is a secondary analysis of previously published data from the Department of Defense Trauma Registry. The casualties were categorized as special operations if they were 18-series, Navy SEAL, Pararescue Jumper, Tactical Air Control Party, Combat Controller, and Marine Corps Force Reconnaissance. The remainder with a documented military occupational specialty (MOS) were classified as conventional forces.

RESULTS

Within our dataset, a MOS was categorizable for 1806 conventional and 130 special operations. Conventional forces were younger age (24 versus 30, p is less than 0.001). Conventional forces had a higher proportion of explosive injuries (61% versus 44%) but a lower proportion of firearm injuries (22% versus 42%, p is less than 0.001). The median injury severity scores were similar between the groups. Conventional forces had lower rates of documentation for all metrics: pulse, respiratory rate, blood pressure, oxygen saturation, Glasgow Coma Scale, and pain score. On adjusted analyses, SOF had higher odds of receiving an extremity splint, packed red blood cells, whole blood, tranexamic acid, ketamine, and fentanyl.

CONCLUSION

SOF had consistently better medical documentation rates, more use of ketamine and fentanyl, less morphine administration, and lower threshold for use of blood products in both unadjusted and adjusted analyses. Our findings suggest lessons learned from the SOF medics should be extrapolated to the conventional forces for improved medical care.

Lessons from the Fallen: An After-Action Review of Prehospital Casualty Data during the Global War on Terror

BACKGROUND

The US military's recent involvement in long standing conflict has caused the pioneering of many lifesaving medical advances, often made possible by data-driven research. However, future advances in battlefield medicine will likely require greater data fidelity than is currently attainable. Continuing to improve survival rates will require data which establishes the relative contributions to preventable mortality and guides future interventions. Prehospital data, particularly that from Tactical Combat Casualty Care (TCCC) Cards and TCCC After Action Reports (TCCC AARs), are notoriously inconsistent in reaching searchable databases for formal evaluation. While the military has begun incorporating more modern technology in advanced data capture over the past few years like the Air Force's Battlefield Assisted Trauma Distributed Observation Kit (BATDOK) and the Army's Medical Hands-free Unified Broadcast system (MEDHUB), more analysis weighing the advantages and disadvantages of substituting analog solutions is needed.

DISCUSSION

We propose 3 changes which may aid prehospital data capture and facilitate analysis: reexamine the current format of TCCC Cards and consider reducing the number of available datapoints to streamline completion, implement a military-wide mandate for all Role 1 providers to complete a TCCC AAR within 24 hours of a casualty event, and formalize the process of requesting de-identified data from the Armed Forces Medical Examiner System (AFMES) database.

CONCLUSION

Reflecting on the state of US military medicine after 20 years of war, an important focus is improving the way prehospital data is gathered and analyzed by the military. There are steps we can take now to enhance our capabilities.

A Narrative Review of Traumatic Pneumothorax Diagnoses and Management

BACKGROUND

Correct identification and rapid intervention of a traumatic pneumothorax is necessary to avoid hemodynamic collapse and subsequent morbidity and mortality. The purpose of this clinical review is to summarize the evaluation and best treatment strategies to improve outcomes in combat casualties. Blunt, explosive, and penetrating trauma are the 3 etiologies for causing a traumatic pneumothorax. Blunt trauma tends to be more common, but all etiologies require similar treatment. The current standard to diagnose pneumothorax is through imaging to include ultrasound, chest x-ray, or computed tomography. A physical exam aids in the diagnosis especially when few other resources are available. Recent studies on the treatment of a small, closed pneumothorax involve conservative care, which includes close observation of the patient and monitoring supplemental oxygen. For a large, closed pneumothorax, conservative treatment is still a possible option, but manual aspiration may be required. Less often, a needle or tube thoracostomy is needed to reinflate the lung. Large, open pneumothoraxes require the most invasive treatment with current guidelines recommending tube thoracostomy. More invasive management options can result in higher rates of complications. Given the significant variability in practice patterns, most notable in resource limited settings, the areas for potential research are presented.

Placement of Antibiotic Powder in Open Fracture Wounds during the Emergency Room (POWDER): Design and Rationale for an Investigation of the Acute Application of Topical Antibiotic Powder in Open Fracture Wounds for Infection Prophylaxis

BACKGROUND

Open fractures are at high risk for complications both in the military and civilian setting. Treatments to prevent fractures are limited in the Role 1 (prehospital, battalion aid station) setting. The goal of this study is to assess the efficacy of topical vancomycin powder, administered within 24 hours of an open fracture injury, in the prevention of infection and infection-related complications.

METHODS

The POWDER study is a multicenter, prospective, randomized controlled clinical trial using a pragmatic open-label design. We will recruit 200 long bone open fracture patients from University Hospital at University of Texas Health at San Antonio (UTHSA) and the Brooke Army Medical Center (BAMC). We will screen and randomize patients in a 1:1 ratio to receive either usual care plus 2g topical vancomycin or usual care only. The primary objective of this study is to compare the proportion of infection and infection-related complications which occur in the 2 arms. An additional objective is to develop a risk-prediction model for open fracture wound complications.

CONCLUSIONS

The infection rates seen in open fractures remain alarmingly high in both combat and civilian settings. Several orthopedic surgery studies suggest vancomycin powder is effective in reducing surgical site infections when applied topically at the time of wound closure. We expect to see a reduction in infections in open fracture injuries treated acutely with vancomycin powder. This study may provide important information regarding the use of local vancomycin powder during the acute treatment of open fractures. If shown to be efficacious, vancomycin powder could provide a simple, time- and cost-effective infection prophylaxis strategy for these injuries.

Airway Management during Large-Scale Combat Operations: A Narrative Review of Capability Requirements

Large-scale combat and multi-domain operations will pose unprecedented challenges to the military healthcare system. This scoping review examines the specific challenges related to the management of airway compromise, the second leading cause of potentially preventable death on the battlefield. Closing existing capability gaps will require a comprehensive approach across all components of the Joint Capabilities Integration Development System. In this, we present the case for a change in doctrine to selectively provide definitive airway management in prehospital settings to maximize the effectiveness of limited resources. Organizational changes to optimize training and efficiency in delivery of complex airway intervention include centralization of assigned healthcare personnel. Training must vastly increase opportunities for live tissue and patient experiences to obtain repetitions of both non-invasive and definitive airway procedures. Potential materiel solutions include extra-glottic devices, bag-valve masks, video laryngoscopes, and oxygen generators all ruggedized and capable of operations in austere settings. Leadership and education changes must formalize more robust airway skills into the initial training curricula for more healthcare personnel who will potentially need to perform these life-saving interventions. Simultaneously, personnel changes should expand authorizations for clinicians with advanced airway skills to the lowest echelons of care. Finally, existing medical training and treatment facilities must expand as necessary to accommodate the training and skill maintenance of these personnel.

Can Military Role 1 Practitioners Maintain Their Skills Working at Civilian Level 1 Trauma Centers: A Retrospective, Cross-Sectional Study

BACKGROUND

Introduction: Military Role 1 practitioners have difficulty maintaining skill competency by working solely in military medical treatment facilities. Recognizing this, the Army Medical Department has renewed focus on physician specialty-specific Individual Critical Task Lists (ICTL) and is increasing the number of military-civilian partnerships, wherein small military treatment teams work full-time in civilian trauma centers. Yet, data to validate this approach is lacking. We hypothesize military Role 1 practitioners working full-time at a civilian Level 1 trauma center would attain similar resuscitation-specific procedural frequency to providers deployed to an active combat zone, and use the emergency medicine (EM) ICTL to compare select procedural frequency between a cohort of trauma patients from a civilian Level 1 trauma center and a cohort of combat casualties from the Department of Defense Trauma Registry (DODTR).

METHODS

We compared a selected subset of critically-injured, military-aged (18-35 years) trauma patients who were seen in a Level I Trauma Center emergency department (ED) between January 1, 2016 and December 31, 2017 and dispositioned directly either to the operating room, intensive care unit, or morgue to a selected cohort from the Department of Defense Trauma Registry (DODTR) who were seen in EDs in Iraq and Afghanistan between January 2007 and August 2016 using descriptive statistics. The primary outcome was the frequency of ICTL procedures performed, and the secondary outcome was injury severity.

RESULTS

We identified 843 civilian patients meeting inclusion criteria, of 1,719 military-aged patients captured by the trauma registry during the study. The selected cohort from the DODTR included 27,359 patients. Demographics were similar between the 2 groups, except the DODTR cohort included significantly more patients with blast trauma (55% versus 0.4%). We found similar ICTL procedural frequency (1 procedure for every 1.84 patients in the civilian cohort compared to one procedure/1.52 patients in the military cohort).

CONCLUSION

Role-1 ICTL trauma procedures were performed at similar frequencies between civilian patients seen at a Level 1 trauma center and combat casualties. With proper practice implementation, the opportunity exists for Role 1 practitioners to maintain their trauma resuscitation skills at civilian trauma centers.

Occam's Razor and Prehospital Documentation: When the Simpler Solution Resulted in Better Documentation

INTRODUCTION

The Tactical Combat Casualty Care (TCCC) card has undergone several changes since its first introduction in 1996. In 2013, updates to the card included more data points to increase prehospital documentation quality and enable performance improvement. This study reviews the proportions of data collected before and after the implementation of the new TCCC card.

METHODS

This is a secondary analysis of a previously described dataset from the Department of Defense Trauma Registry (DODTR) focused on prehospital medical care. In this sub-analysis, we defined the pre-implementation period as 2009-2013 followed by a 1-year run-in with the post-implementation period as 2015-2019. Our primary outcome was documentation of a pulse rate and our secondary outcomes included documentation of other vital signs. We used multivariable logistic regression models to adjust for confounders.

RESULTS

There were 18,182 encounters that met inclusion for this analysis-14,711 before and 3,471 after the update. Across all vital signs, there was a peak around 2012-2013 with a drop noted in 2015. Comparing the preimplementation and post-implementation groups, there were higher proportions with documentation of a pulse rate (62% versus 49%), respirations (51% versus 45%), systolic pressure (53% versus 46%), diastolic pressure (49% versus 41%), oxygen saturation (55% versus 46%), and pain score (27% versus 19%, all p is less than 0.001) in the pre-implementation group. When adjusting for injury severity score (ISS), casualty category, and year of injury, the odds ratio of documentation of a pulse after implementation was 0.01 (95% CI: 0.00-0.01). When adjusting for ISS and casualty category, the odds ratio was 0.64 (95% CI: 0.60-0.70). When adjusting for ISS only, the odds ratio was 0.58 (95% CI: 0.54-0.63).

CONCLUSIONS

Implementation of the new TCCC card resulted in overall lower documentation proportions which persisted after adjusting for measurable confounders.

Can Military Role 1 Practitioners Maintain Their Skills Working at Civilian Level 1 Trauma Centers: A Retrospective, Cross-Sectional Study

BACKGROUND

Introduction: Military Role 1 practitioners have difficulty maintaining skill competency by working solely in military medical treatment facilities. Recognizing this, the Army Medical Department has renewed focus on physician specialty-specific Individual Critical Task Lists (ICTL) and is increasing the number of military-civilian partnerships, wherein small military treatment teams work full-time in civilian trauma centers. Yet, data to validate this approach is lacking. We hypothesize military Role 1 practitioners working full-time at a civilian Level 1 trauma center would attain similar resuscitation-specific procedural frequency to providers deployed to an active combat zone, and use the emergency medicine (EM) ICTL to compare select procedural frequency between a cohort of trauma patients from a civilian Level 1 trauma center and a cohort of combat casualties from the Department of Defense Trauma Registry (DODTR).

METHODS

We compared a selected subset of critically-injured, military-aged (18-35 years) trauma patients who were seen in a Level I Trauma Center emergency department (ED) between January 1, 2016 and December 31, 2017 and dispositioned directly either to the operating room, intensive care unit, or morgue to a selected cohort from the Department of Defense Trauma Registry (DODTR) who were seen in EDs in Iraq and Afghanistan between January 2007 and August 2016 using descriptive statistics. The primary outcome was the frequency of ICTL procedures performed, and the secondary outcome was injury severity.

RESULTS

We identified 843 civilian patients meeting inclusion criteria, of 1,719 military-aged patients captured by the trauma registry during the study. The selected cohort from the DODTR included 27,359 patients. Demographics were similar between the 2 groups, except the DODTR cohort included significantly more patients with blast trauma (55% versus 0.4%). We found similar ICTL procedural frequency (1 procedure for every 1.84 patients in the civilian cohort compared to one procedure/1.52 patients in the military cohort).

CONCLUSION

Role-1 ICTL trauma procedures were performed at similar frequencies between civilian patients seen at a Level 1 trauma center and combat casualties. With proper practice implementation, the opportunity exists for Role 1 practitioners to maintain their trauma resuscitation skills at civilian trauma centers.

Antarctic Evacuation: A Retrospective Epidemiological Study of Medical Evacuations on US Military Aircraft in Antarctica

BACKGROUND

The international community has shown increasing interest in the Arctic and Antarctic due to the value polar regions have in terms of environmental research, natural resources, and national defense. The US Government maintains several permanent research and military facilities in polar regions. Medical evacuation (MEDEVAC) from these facilities can be limited for prolonged periods of time due to their extreme climates. Published data regarding MEDEVACs from these facilities is extremely limited.

METHODS

Evacuations on military aircraft registered in the Transportation Command Regulation and Command and Control Evacuation System (TRAC2ES) database in a previously de-identified dataset were queried for events from McMurdo, Antarctica. The data was analyzed to determine the number of evacuations, reasons for evacuation, and additional demographic data.

RESULTS

There were 31 evacuations from McMurdo Station and Scott Amundsen South Pole Station for 29 unique patients recorded in the available TRAC2ES dataset. Reasons for evacuation included traumatic brain/head injury, behavioral health concerns, extremity injuries, pregnancy, and various other medical/surgical concerns.

CONCLUSIONS

MEDEVAC was typically required for advanced diagnostic/treatment modalities or if a patient could no longer fulfill his/her duties. Most evacuations were not directly related to environmental exposure. Given the climate in polar regions can preclude timely evacuation for large periods of time, the need for evacuation must be anticipated and mitigated whenever possible. Better data is needed to guide staffing and mission planning in this remote location.

Clinical Assessment of Low Calcium In traUMa (CALCIUM)

Major trauma frequently occurs in the deployed, combat setting and is especially applicable in the recent conflicts with explosives dominating the combat wounded. In future near-peer conflicts, we will likely face even more profound weapons including mortars and artillery. As such, the number of severely wounded will likely increase. Hypocalcemia frequently occurs after blood transfusions, secondary to the preservatives in the blood products; however, recent data suggests major trauma in and of itself is a risk factor for hypocalcemia. Calcium is a major ion involved in heart contractility; thus, hypocalcemia can lead to poor contractility. Smaller studies have linked hypocalcemia to worse outcomes, but it remains unclear what causes hypocalcemia and if intervening could potentially save lives. The objective of this study is to determine the incidence of hypocalcemia on hospital arrival and the association with survival. We are seeking to address the following scientific questions, (1) Is hypocalcemia present following traumatic injury prior to transfusion during resuscitation? (2) Does hypocalcemia influence the amount of blood products transfused? (3) To what extent is hypocalcemia further exacerbated by transfusion? (4) What is the relationship between hypocalcemia following traumatic injury and mortality? We will conduct a multicenter, prospective, observational study. We will gather ionized calcium levels at 0, 3, 6, 12, 18, and 24 hours as part of scheduled calcium measurements. This will ensure we have accurate data to assess the early and late effects of hypocalcemia throughout the course of resuscitation and hemorrhage control. These data will be captured by a trained study team at every site. Our findings will inform clinical practice guidelines and optimize the care delivered in the combat and civilian trauma setting. We are seeking 391 patients with complete data to meet our a priori inclusion criteria. Our study will have major immediate short-term findings including risk prediction modeling to assess who is at risk for hypocalcemia, data assessing interventions associated with the incidence of hypocalcemia, and outcome data including mortality and its link to early hypocalcemia.

A Comparison of Injury Patterns and Interventions among US Military Special Operations Versus Conventional Forces Combatants

BACKGROUND

Over the course of the US' Global War on Terrorism, its military has utilized both conventional and special operations forces (SOF). These entities have sustained and treated battlefield casualties in the prehospital, Role 1 setting, while also making efforts to mitigate risks to the force and pursuing improved interventions. The goal of this study is to compare outcomes and prehospital medical interventions between SOF and conventional military combat casualties.

METHODS

This is a secondary analysis of previously published data from the Department of Defense Trauma Registry. The casualties were categorized as special operations if they were 18-series, Navy SEAL, Pararescue Jumper, Tactical Air Control Party, Combat Controller, and Marine Corps Force Reconnaissance. The remainder with a documented military occupational specialty (MOS) were classified as conventional forces.

RESULTS

Within our dataset, a MOS was categorizable for 1806 conventional and 130 special operations. Conventional forces were younger age (24 versus 30, p is less than 0.001). Conventional forces had a higher proportion of explosive injuries (61% versus 44%) but a lower proportion of firearm injuries (22% versus 42%, p is less than 0.001). The median injury severity scores were similar between the groups. Conventional forces had lower rates of documentation for all metrics: pulse, respiratory rate, blood pressure, oxygen saturation, Glasgow Coma Scale, and pain score. On adjusted analyses, SOF had higher odds of receiving an extremity splint, packed red blood cells, whole blood, tranexamic acid, ketamine, and fentanyl.

CONCLUSION

SOF had consistently better medical documentation rates, more use of ketamine and fentanyl, less morphine administration, and lower threshold for use of blood products in both unadjusted and adjusted analyses. Our findings suggest lessons learned from the SOF medics should be extrapolated to the conventional forces for improved medical care.

A Comparison of Combat Casualty Outcomes after Prehospital Versus Military Treatment Facility Airway Management

BACKGROUND

Airway obstruction is the second leading cause of potentially survivable death on the battlefield. Previous studies demonstrate casualties undergoing airway interventions have worse outcomes when the procedure occurs in the prehospital setting versus the military treatment facility (MTF) setting. We compare outcomes between casualties undergoing airway management in these 2 settings using the Department of Defense Trauma Registry (DODTR).

METHODS

This is a secondary analysis of a previously described dataset from the DODTR. We included US military casualties with at least 24 hours on the ventilator. We compared casualties who underwent intubation in the prehospital setting versus hospital setting. Multivariable logistic regression models were constructed to adjust for available confounders.

RESULTS

There were 2,124 that met inclusion for this analysis-278 in the prehospital cohort and 1,846 in the MTF cohort. Median injury severity scores were higher in the prehospital cohort (25 versus 22, p is less than 0.001). The survival to discharge was lower in the prehospital cohort (80% versus 93%, p is less than 0.001). On multivariable logistic regression model, when adjusting for injury severity score, mechanism of injury, and first 24-hour blood products, the odds of survival were 0.34 (95% CI 0.23-0.50) for those intubated prehospital versus MTF.

CONCLUSIONS

We found worse survival for those with prehospital airway intervention versus those in the MTFsetting. These findings persisted after adjustment for measurable confounders. Our findings suggest prehospital-focused improvements in airway interventions are needed and/or robust methods for rapid evacuation to an MTF for airway intervention.

Placement of Antibiotic Powder in Open Fracture Wounds during the Emergency Room (POWDER): Design and Rationale for an Investigation of the Acute Application of Topical Antibiotic Powder in Open Fracture Wounds for Infection Prophylaxis

BACKGROUND

Open fractures are at high risk for complications both in the military and civilian setting. Treatments to prevent fractures are limited in the Role 1 (prehospital, battalion aid station) setting. The goal of this study is to assess the efficacy of topical vancomycin powder, administered within 24 hours of an open fracture injury, in the prevention of infection and infection-related complications.

METHODS

The POWDER study is a multicenter, prospective, randomized controlled clinical trial using a pragmatic open-label design. We will recruit 200 long bone open fracture patients from University Hospital at University of Texas Health at San Antonio (UTHSA) and the Brooke Army Medical Center (BAMC). We will screen and randomize patients in a 1:1 ratio to receive either usual care plus 2g topical vancomycin or usual care only. The primary objective of this study is to compare the proportion of infection and infection-related complications which occur in the 2 arms. An additional objective is to develop a risk-prediction model for open fracture wound complications.

CONCLUSIONS

The infection rates seen in open fractures remain alarmingly high in both combat and civilian settings. Several orthopedic surgery studies suggest vancomycin powder is effective in reducing surgical site infections when applied topically at the time of wound closure. We expect to see a reduction in infections in open fracture injuries treated acutely with vancomycin powder. This study may provide important information regarding the use of local vancomycin powder during the acute treatment of open fractures. If shown to be efficacious, vancomycin powder could provide a simple, time- and cost-effective infection prophylaxis strategy for these injuries.

Male Genitourinary Injuries in Combat - A Review of United States and British Forces in Afghanistan and Iraq: 2001-2013

As we look to the current conflict in Ukraine, our service members deploy to periphery Northern Atlantic Treaty Organization countries. At the same time, we see an increase in high-kinetic wounding patterns in the United States. We look to the important underrepresented topic of urologic trauma in combat casualties to prepare for the wounds of modern warfare. Genitourinary wounds are increasingly frequent and affect both military and civilian casualties; civilian urologists and deployed surgeons require proficiency in treating these wounds. We present this review of urologic trauma in Afghanistan and Iraq to inform considerations for urologic surgeons and first responders.

A Comparison of Combat Casualty Outcomes after Prehospital Versus Military Treatment Facility Airway Management

BACKGROUND

Airway obstruction is the second leading cause of potentially survivable death on the battlefield. Previous studies demonstrate casualties undergoing airway interventions have worse outcomes when the procedure occurs in the prehospital setting versus the military treatment facility (MTF) setting. We compare outcomes between casualties undergoing airway management in these 2 settings using the Department of Defense Trauma Registry (DODTR).

METHODS

This is a secondary analysis of a previously described dataset from the DODTR. We included US military casualties with at least 24 hours on the ventilator. We compared casualties who underwent intubation in the prehospital setting versus hospital setting. Multivariable logistic regression models were constructed to adjust for available confounders.

RESULTS

There were 2,124 that met inclusion for this analysis-278 in the prehospital cohort and 1,846 in the MTF cohort. Median injury severity scores were higher in the prehospital cohort (25 versus 22, p is less than 0.001). The survival to discharge was lower in the prehospital cohort (80% versus 93%, p is less than 0.001). On multivariable logistic regression model, when adjusting for injury severity score, mechanism of injury, and first 24-hour blood products, the odds of survival were 0.34 (95% CI 0.23-0.50) for those intubated prehospital versus MTF.

CONCLUSIONS

We found worse survival for those with prehospital airway intervention versus those in the MTFsetting. These findings persisted after adjustment for measurable confounders. Our findings suggest prehospital-focused improvements in airway interventions are needed and/or robust methods for rapid evacuation to an MTF for airway intervention.

Occam's Razor and Prehospital Documentation: When the Simpler Solution Resulted in Better Documentation

INTRODUCTION

The Tactical Combat Casualty Care (TCCC) card has undergone several changes since its first introduction in 1996. In 2013, updates to the card included more data points to increase prehospital documentation quality and enable performance improvement. This study reviews the proportions of data collected before and after the implementation of the new TCCC card.

METHODS

This is a secondary analysis of a previously described dataset from the Department of Defense Trauma Registry (DODTR) focused on prehospital medical care. In this sub-analysis, we defined the pre-implementation period as 2009-2013 followed by a 1-year run-in with the post-implementation period as 2015-2019. Our primary outcome was documentation of a pulse rate and our secondary outcomes included documentation of other vital signs. We used multivariable logistic regression models to adjust for confounders.

RESULTS

There were 18,182 encounters that met inclusion for this analysis-14,711 before and 3,471 after the update. Across all vital signs, there was a peak around 2012-2013 with a drop noted in 2015. Comparing the preimplementation and post-implementation groups, there were higher proportions with documentation of a pulse rate (62% versus 49%), respirations (51% versus 45%), systolic pressure (53% versus 46%), diastolic pressure (49% versus 41%), oxygen saturation (55% versus 46%), and pain score (27% versus 19%, all p is less than 0.001) in the pre-implementation group. When adjusting for injury severity score (ISS), casualty category, and year of injury, the odds ratio of documentation of a pulse after implementation was 0.01 (95% CI: 0.00-0.01). When adjusting for ISS and casualty category, the odds ratio was 0.64 (95% CI: 0.60-0.70). When adjusting for ISS only, the odds ratio was 0.58 (95% CI: 0.54-0.63).

CONCLUSIONS

Implementation of the new TCCC card resulted in overall lower documentation proportions which persisted after adjusting for measurable confounders.

Airway Management during Large-Scale Combat Operations: A Narrative Review of Capability Requirements

Large-scale combat and multi-domain operations will pose unprecedented challenges to the military healthcare system. This scoping review examines the specific challenges related to the management of airway compromise, the second leading cause of potentially preventable death on the battlefield. Closing existing capability gaps will require a comprehensive approach across all components of the Joint Capabilities Integration Development System. In this, we present the case for a change in doctrine to selectively provide definitive airway management in prehospital settings to maximize the effectiveness of limited resources. Organizational changes to optimize training and efficiency in delivery of complex airway intervention include centralization of assigned healthcare personnel. Training must vastly increase opportunities for live tissue and patient experiences to obtain repetitions of both non-invasive and definitive airway procedures. Potential materiel solutions include extra-glottic devices, bag-valve masks, video laryngoscopes, and oxygen generators all ruggedized and capable of operations in austere settings. Leadership and education changes must formalize more robust airway skills into the initial training curricula for more healthcare personnel who will potentially need to perform these life-saving interventions. Simultaneously, personnel changes should expand authorizations for clinicians with advanced airway skills to the lowest echelons of care. Finally, existing medical training and treatment facilities must expand as necessary to accommodate the training and skill maintenance of these personnel.

Incidence of Airway Interventions in the Setting of Serious Facial Trauma

BACKGROUND

Airway obstruction is the second leading cause of preventable death on the battlefield. Most airway obstruction occurs secondary to traumatic disruptions of the airway anatomical structures. Facial trauma is frequently cited as rationale for maintaining cricothyrotomy in the medics' skill set over the supraglottic airways more commonly used in the civilian setting.

METHODS

We used a series of emergency department procedure codes to identify patients within the Department of Defense Trauma Registry (DoDTR) from January 2007 to August 2016. This is a sub-group analysis of casualties with documented serious facial trauma based on an abbreviated injury scale of 3 or greater for the facial body region.

RESULTS

Our predefined search codes captured 28,222 DoDTR casualties, of which we identified 136 (0.5%) casualties with serious facial trauma, of which 19 of the 136 had documentation of an airway intervention (13.9%). No casualties with serious facial trauma underwent nasopharyngeal airway (NPA) placement, 0.04% underwent cricothyrotomy (n = 10), 0.03% underwent intubation (n = 9), and a single subject underwent supraglottic airway (SGA) placement (<0.01%). We only identified four casualties (0.01% of total dataset) with an isolated injury to the face.

CONCLUSIONS

Serious injury to the face rarely occurred among trauma casualties within the DoDTR. In this subgroup analysis of casualties with serious facial trauma, the incidence of airway interventions to include cricothyrotomy was exceedingly low. However, within this small subset the mortality rate is high and thus better methods for airway management need to be developed.