Airborne! UAV delivery of blood products and medical logistics for combat zones.

BACKGROUND: Innovative solutions to resupply critical medical logistics and blood products may be required in future near-peer conflicts. Unmanned aerial vehicles (UAVs) are increasingly being used in austere environments and may be a viable platform for medical resupply and the transport of blood products. METHODS: A literature review on PubMed and Google Scholar up to March of 2022 yielded a total of 27 articles that were included in this narrative review. The objectives of this article are to discuss the current limitations of prehospital blood transfusion in military settings, discuss the current uses of UAVs for medical logistics, and highlight the ongoing research surrounding UAVs for blood product delivery. DISCUSSION: UAVs allow for the timely delivery of medical supplies in numerous settings and have been utilized for both military and civilian purposes. Investigations into the effects of aeromedical transportation on blood products have found minimal blood product degradation when appropriately thermoregulated and delivered in a manner that minimizes trauma. UAV delivery of blood products is now actively being explored by numerous entities around the globe. Current limitations surrounding the lack of high-quality safety data, engineering constraints over carrying capacity, storage capability, and distance traveled, as well as air space regulations persist. CONCLUSION: UAVs may offer a novel solution for the transport of medical supplies and blood products in a safe and timely manner for the forward-deployed setting. Further research on optimal UAV design, optimal delivery techniques, and blood product safety following transport should be explored prior to implementation.

Comparison of military and civilian surgeon outcomes with emergent trauma laparotomy in a mature military-civilian partnership.

Introduction: Medical readiness is of paramount concern for active-duty military providers. Low volumes of complex trauma in military treatment facilities has driven the armed forces to embed surgeons in high-volume civilian centers to maintain clinical readiness. It is unclear what impact this strategy may have on patient outcomes in these centers. We sought to compare emergent trauma laparotomy (ETL) outcomes between active-duty Air Force Special Operations Surgical Team (SOST) general surgeons and civilian faculty at an American College of Surgeons verified level 1 trauma center with a well-established military-civilian partnership. Methods: Retrospective review of a prospectively maintained, single-center database of ETL from 2019 to 2022 was performed. ETL was defined as laparotomy from trauma bay within 90 min of patient arrival. The primary outcome was to assess for all-cause mortality differences at multiple time points. Results: 514 ETL were performed during the study period. 22% (113 of 514) of patients were hypotensive (systolic blood pressure ≤90 mm Hg) on arrival. Six SOST surgeons performed 43 ETL compared with 471 ETL by civilian faculty. There were no differences in median ED length of stay (27 min vs 22 min; p=0.21), but operative duration was significantly longer for SOST surgeons (129 min vs 110 min; p=0.01). There were no differences in intraoperative (5% vs 2%; p=0.30), 6-hour (3% vs 5%; p=0.64), 24-hour (5% vs 5%; p=1.0), or in-hospital mortality rates (5% vs 8%; p=0.56) between SOST and civilian surgeons. SOST surgeons did not significantly impact the odds of 24-hour mortality on multivariable analysis (OR 0.78; 95% CI 0.10, 6.09). Conclusion: Trauma-related mortality for patients undergoing ETL was not impacted by SOST surgeons when compared with their civilian counterparts. Military surgeons may benefit from the valuable clinical experience and mentorship of experienced civilian trauma surgeons at high volume trauma centers without creating a deficit in the quality of care provided. Level of evidence: Level IV, therapeutic/care management.

Preferential whole blood transfusion during the early resuscitation period is associated with decreased mortality and transfusion requirements in traumatically injured patients.

Introduction: Whole blood (WB) transfusion represents a promising resuscitation strategy for trauma patients. However, a paucity of data surrounding the optimal incorporation of WB into resuscitation strategies persists. We hypothesized that traumatically injured patients who received a greater proportion of WB compared with blood product components during their resuscitative efforts would have improved early mortality outcomes and decreased transfusion requirements compared with those who received a greater proportion of blood product components. Methods: Retrospective review from our Level 1 trauma center of trauma patients during their initial resuscitation (2019-2022) was performed. WB to packed red blood cell ratios (WB:RBC) were assigned to patients based on their respective blood product resuscitation at 1, 2, 3, and 24 hours from presentation. Multivariable regression models were constructed to assess the relationship of WB:RBC to 4 and 24-hour mortality, and 24-hour transfusion requirements. Results: 390 patients were evaluated (79% male, median age of 33 years old, 48% penetrating injury rate, and a median Injury Severity Score of 27). Overall mortality at 4 hours was 9%, while 24-hour mortality was 12%. A significantly decreased 4-hour mortality was demonstrated in patients who displayed a WB:RBC≥1 at 1 hour (5.9% vs. 12.3%; OR 0.17, p=0.015), 2 hours (5.5% vs. 13%; OR 0.16, p=0.019), and 3 hours (5.5% vs. 13%, OR 0.18, p<0.01), while a decreased 24-hour mortality was displayed in those with a WB:RBC≥1 at 24 hours (7.9% vs. 14.6%, OR 0.21, p=0.01). Overall 24-hour transfusion requirements were significantly decreased within the WB:RBC≥1 cohort (12.1 units vs. 24.4 units, p<0.01). Conclusion: Preferential WB transfusion compared with a balanced transfusion strategy during the early resuscitative period was associated with a lower 4 and 24-hour mortality, as well as decreased 24-hour transfusion requirements, in trauma patients. Future prospective studies are warranted to determine the optimal use of WB in trauma. Level of evidence: Level III/therapeutic.

Early Use of Extracorporeal Membrane Oxygenation for Traumatically Injured Patients: A National Trauma Database Analysis.

INTRODUCTION: Extracorporeal membrane oxygenation (ECMO) in acute trauma patients is a poorly characterized event. While ECMO most commonly has been deployed for advanced cardiopulmonary or respiratory failure following initial resuscitation, growing levels of evidence for out of hospital cardiac arrest support early ECMO cannulation as part of resuscitative efforts. We sought to perform a descriptive analysis evaluating traumatically injured patients, who were placed on ECMO, during their initial resuscitation period. METHODS: We performed a retrospective analysis of the Trauma Quality Improvement Program Database from 2017 to 2019. All traumatically injured patients who received ECMO within the first 24 hours of their hospitalization were assessed. Descriptive statistics were used to define patient characteristics and injury patterns associated with the need for ECMO, while mortality represented the primary outcome evaluated. RESULTS: A total of 696 trauma patients received ECMO during their hospitalization, of which 221 were placed on ECMO within the first 24 hours. Early ECMO patients were on average 32.5 years old, 86% male, and sustained a penetrating injury 9% of the time. The average ISS was 30.7, and the overall mortality rate was 41.2%. Prehospital cardiac arrest was noted in 18.2% of the patient population resulting in a 46.8% mortality. Of those who underwent resuscitative thoracotomy, a 53.3% mortality rate was present. CONCLUSION: Early cannulation for ECMO in severely injured patients may provide an opportunity for rescue therapy following severe injury patterns. Further evaluation regarding the safety profile, cannulation strategies, and optimal injury patterns for these techniques should be evaluated.

Balanced resuscitation and earlier mortality end points: bayesian post hoc analysis of the PROPPR trial.

Introduction: The Pragmatic Randomized Optimal Platelet and Plasma Ratios (PROPPR) trial failed to demonstrate a mortality difference for hemorrhaging patients receiving a balanced (1:1:1) vs a 1:1:2 resuscitation at 24 hours and 30 days. Recent guidelines recommend earlier mortality end points for hemorrhage-control trials, and the use of contemporary statistical methods. The aim of this post hoc analysis of the PROPPR trial was to evaluate the impact of a balanced resuscitation strategy at early resuscitation time points using a Bayesian analytical framework. Methods: Bayesian hierarchical models were created to assess mortality differences at the 1, 3, 6, 12, 18, and 24 hours time points between study cohorts. Posterior probabilities and Bayes factors were calculated for each time point. Results: A 1:1:1 resuscitation displayed a 96%, 99%, 94%, 92%, 96%, and 94% probability for mortality benefit at 1, 3, 6, 12, 18, and 24 hours, respectively, when compared with a 1:1:2 approach. Associated Bayes factors for each respective time period were 21.2, 142, 14.9, 11.4, 26.4, and 15.5, indicating 'strong' to 'decisive' supporting evidence in favor of balanced transfusions. Conclusion: This analysis provides evidence in support that a 1:1:1 resuscitation has a high probability of mortality benefit when compared with a 1:1:2 strategy, especially at the newly defined more proximate time points during the resuscitative period. Researchers should consider using Bayesian approaches, along with more proximate end points when assessing hemorrhage-related mortality, for the analysis of future clinical trials. Level of evidence: Level III/Therapeutic.

The 16-year evolution of a military-civilian partnership: The University of Alabama at Birmingham experience.

BACKGROUND: At the University of Alabama at Birmingham (UAB), a multi-tiered military-civilian partnership (MCP) has evolved since 2006. We aimed to outline this model to facilitate potential replication nationally. METHODS: We performed a comprehensive review of the partnership between UAB, the United States Air Force Special Operations Command, and the Department of Defense (DoD) reviewing key documents and conducting interviews with providers. As a purely descriptive study, this project did not involve any patient data acquisition or analysis and therefore was exempt from institutional review board approval per institutional policy. RESULTS: At the time of this review, six core programs existed targeting training, clinical proficiency, and research. Training: (1) The Special Operations Center for Medical Integration and Development trains up to 144 combat medics yearly. (2) UAB trains one integrated military Surgery resident yearly with two additional civilian-sponsored military residents in Emergency Medicine. (3) UAB's Surgical Critical Care Fellowship had one National Guard member with two incoming Active-Duty, one Reservist and one prior service member in August 2022. Clinical Proficiency: (4) UAB hosts four permanently assigned United States Air Force Special Operations Command Special Operations Surgical Teams composed of general surgeons, anesthesiologists, certified registered nurse anesthetists, surgical technologists, emergency physicians, critical care registered nurses, and respiratory therapists totaling 24 permanently assigned active-duty health care professionals. (5) In addition, two fellowship-trained Air Force Trauma Critical Care Surgeons, one Active-Duty and one Reservist, are permanently assigned to UAB. These clinicians participate fully and independently in the routine care of patients alongside their civilian counterparts. Research: (6) UAB's Division of Trauma and Acute Care Surgery is currently conducting nine DoD-funded research projects totaling $6,482,790, and four research projects with military relevance funded by other agencies totaling $15,357,191. CONCLUSION: The collaboration between UAB and various elements within the DoD illustrates a comprehensive approach to MCP. Replicating appropriate components of this model nationally may aid in the development of a truly integrated trauma system best prepared for the challenges of the future. LEVEL OF EVIDENCE: Economic and Value-based Evaluations; Level IV.

The last days: The medical response of United States and allied military teams during the Afghanistan Exodus.

OBJECTIVES: The objective of this study is to describe the United States and allied military medical response during the withdrawal from Afghanistan. BACKGROUND: The military withdrawal from Afghanistan concluded with severe hostilities resulting in numerous civilian and military casualties. The clinical care provided by coalition forces capitalized on decades of lessons learned and enabled unprecedented accomplishments. METHODS: In this retrospective, observational analysis, casualty numbers, and operative information was collected and reported from military medical assets in Kabul, Afghanistan. The continuum of medical care and the trauma system, from the point of injury back to the United States was captured and described. RESULTS: Prior to a large suicide bombing resulting in a mass casualty event, the international medical teams managed distinct 45 trauma incidents involving nearly 200 combat and non-combat civilian and military patients over the preceding 3 months. Military medical personnel treated 63 casualties from the Kabul airport suicide attack and performed 15 trauma operations. US air transport teams evacuated 37 patients within 15 hours of the attack. CONCLUSION: Lessons learned from the last 20 years of combat casualty care were successfully implemented during the culmination of the Afghanistan conflict. Ultimately, the effort, teamwork, and system adaptability exemplify not only the attitudes and character of service members who provide modern combat casualty care but also the paramount importance of the battlefield learning health care system. A continued posture to maintain military surgical preparedness in unique environments remain crucial as the US military prepares for the future.Retrospective observational analysis. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level V.