Quantifying the benefit of whole blood on mortality in trauma patients requiring emergent laparotomy.

BACKGROUND: Whole blood (WB) transfusions in trauma represent an increasingly utilized resuscitation strategy in trauma patients. Previous reports suggest a probable mortality benefit with incorporating WB into massive transfusion protocols. However, questions surrounding optimal WB practices persist. We sought to assess the association between the proportion of WB transfused during the initial resuscitative period and its impact on early mortality outcomes for traumatically injured patients. METHODS: We performed a retrospective analysis of severely injured patients requiring emergent laparotomy and ≥ 3 units of red blood cell containing products (WB or packed red blood cells) within the first hour from an ACS Level 1 Trauma Center (2019-2022). Patients were evaluated based on the proportion of WB they received compared to packed red blood cells during their initial resuscitation (high ratio cohort ≥50% WB vs low ratio cohort <50% WB). Multilevel Bayesian regression analyses were performed to calculate the posterior probabilities and risk ratios (RR) associated with a WB predominant resuscitation for early mortality outcomes. RESULTS: 266 patients were analyzed (81% male, mean age of 36 years old, 61% penetrating injury, mean ISS of 30). The mortality was 11% at 4-hours and 14% at 24-hours. The high ratio cohort demonstrated a 99% (RR 0.12; 95% CrI 0.02-0.53) and 99% (RR 0.22; 95% CrI 0.08-0.65) probability of decreased mortality at 4-hours and 24-hours, respectively, compared the low ratio cohort. There was a 94% and 88% probability of at least a 50% mortality relative risk reduction associated with the WB predominate strategy at 4 hours and 24 hours, respectively. CONCLUSION: Preferential transfusion of WB during the initial resuscitation demonstrated a 99% probability of being superior to component predominant resuscitations with regards to 4 and 24-hour mortality suggesting that WB predominant resuscitations may be superior for improving early mortality. Prospective, randomized trials should be sought. LEVEL OF EVIDENCE: Therapeutic, Level III.

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.

Comparison of Contralateral vs Ipsilateral Vein Graft for Traumatic Vascular Injury Repair: A Cohort From PROOVIT.

Traumatic injury leading to arterial damage has traditionally been repaired using autologous vein graft from the contralateral limb. This often requires a secondary surgical site and the potential of prolonged operative time for patients. We sought to assess the use of ipsilateral vs contralateral vein grafts in patients who experienced traumatic extremity vascular injury. A multicenter database was queried to identify arterial injuries requiring operative intervention with vein grafting. The primary outcome of interest was need for operative reintervention. Secondary outcomes included risk of thrombosis, infection, and intensive care unit length of stay. 358 patients (320 contralateral and 38 ipsilateral) were included in the analysis. The ipsilateral vein cohort did not display a statistically significant decrease in need for reoperation when compared to the contralateral group (11% vs 23%; OR 0.41, 95% CI -0.07-1.3; P = .14). Contralateral repair was associated with longer median intensive care unit (ICU) LOS (4.3 vs 3.1 days; P < .01).

Mortality in hypotensive combat casualties who require emergent laparotomy in the forward deployed environment.

INTRODUCTION: Mortality rates among hypotensive civilian patients requiring emergent laparotomy exceed 40%. Damage control (DCR) principles were incorporated into the military's Clinical Practice Guidelines (CPG) in 2008. We examined combat casualties requiring emergent laparotomy to characterize how mortality rates compare to hypotensive civilian trauma patients. METHODS: The DoD Trauma Registry (2004-2020) was queried for adults who underwent combat laparotomy. Patients who were hypotensive were compared to normotensive patients. Mortality was the outcome of interest. Mortality rates before (2004-2007) and after (2009-2020) DCR CPG implementation were analyzed. RESULTS: 1051 patients were studied. Overall mortality was 6.5% for normotensive casualties and 28.7% for hypotensive casualties. Mortality decreased in normotensive patients but remained unchanged in hypotensive patients following the implementation of the DCR CPG. CONCLUSION: Hypotensive combat casualties undergoing emergent laparotomy demonstrated a mortality rate of 29.5%. Despite many advances, mortality rates remain high in hypotensive patients requiring emergent laparotomy.

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.

Developing the Ready Military Medical Force: military-specific training in Graduate Medical Education.

Introduction: Graduate Medical Education plays a critical role in training the next generation of military physicians, ensuring they are ready to uphold the dual professional requirements inherent to being both a military officer and a military physician. This involves executing the operational duties as a commissioned leader while also providing exceptional medical care in austere environments and in harm's way. The purpose of this study is to review prior efforts at developing and implementing military unique curricula (MUC) in residency training programs. Methods: We performed a literature search in PubMed (MEDLINE), Embase, Web of Science, and the Defense Technical Information Center through August 8, 2023, including terms "graduate medical education" and "military." We included articles if they specifically addressed military curricula in residency with terms including "residency and operational" or "readiness training", "military program", or "military curriculum". Results: We identified 1455 articles based on title and abstract initially and fully reviewed 111. We determined that 64 articles met our inclusion criteria by describing the history or context of MUC, surveys supporting MUC, or military programs or curricula incorporated into residency training or military-specific residency programs. Conclusion: We found that although there have been multiple attempts at establishing MUC across training programs, it is difficult to create a uniform curriculum that can be implemented to train residents to a single standard across services and specialties.

Outcomes of Patients Enrolled in a Prospective and Randomized Trial on Basis of Gestalt Assessment or ABC Score.

INTRODUCTION: The Pragmatic Randomized Optimal Platelet and Plasma Ratios (PROPPR) trial rapidly enrolled patients based on an ABC ≥ 2 score, or Physician Gestalt (PG) when ABC score was <2. The objective of this study was to describe what patients were enrolled by the two methods and whether patient outcomes differed based these enrollments. We hypothesized that there would be no differences in outcomes based on whether patients were enrolled via ABC score or PG. METHODS: Patients were enrolled with an ABC ≥ 2 or by PG when ABC was <2 by the attending trauma surgeon. We compared 1-, 3-, 6-, 12-, 18- and 24-hour mortality, 30-day mortality, time to hemostasis, emergent surgical or interventional radiology procedure and the proportion of patients who required either >10 units of blood in 24 hours or > 3 units in one hour. RESULTS: Of 680 patients, 438 (64%) were enrolled on the basis of an ABC score ≥ 2 and 242 (36% by PG when the ABC score was <2. Patients enrolled by PG were older (median 44, IQR 28-59, p < 0.001), more likely to be white (70.3% vs 60.3%, p = 0.014), and more likely to have been injured by blunt mechanisms (77.3% vs 37.2%, p < 0.001). They were also less hypotensive and less tachycardic than patients enrolled by ABC score (both p < 0.001). The groups had similar Injury Severity Scores in the ABC ≥ 2 and PG groups (26 and 27 respectively) and were equally represented (49.1% and 50.8% respectively) in the 1:1:1 treatment arm. There were no significant differences between the ABC score and PG groups for mortality at any point. Time to hemostasis (108 for patients enrolled on basis of Gestalt, vs. 100 mins for patients enrolled on basis of ABC score), and the proportion of patients requiring a massive transfusion (>10 units/24 h) (44.2% vs. 47.3%), or meeting the critical administration threshold (>3 unit/1 hr) (84.7% vs. 89.5%) were similar (p = 0.071). CONCLUSION: Early identification of trauma patients likely to require a massive transfusion is important for clinical care, resource use, and selection of patients for clinical trials. Patients enrolled in the PROPPR trial based on PG when the ABC score was <2 represented 36% of the patients and had identical outcomes to those enrolled on the basis of an ABC score of ≥2. LEVEL OF EVIDENCE: Level III, Prognostic.

The use of mobile thermal imaging and machine learning technology for the detection of early surgical site infections.

BACKGROUND: Surgical Site Infections (SSI) yield subtle, early signs that are not readily identifiable. This study sought to develop a machine learning algorithm that could identify early SSIs based on thermal images. METHODS: Images were taken of surgical incisions on 193 patients who underwent a variety of surgical procedures. Two neural network models were generated to detect SSIs, one using RGB images, and one incorporating thermal images. Accuracy and Jaccard Index were the primary metrics by which models were evaluated. RESULTS: Only 5 patients in our cohort developed SSIs (2.8%). Models were instead generated to demarcate the wound site. The models had 89-92% accuracy in predicting pixel class. The Jaccard indices for the RGB and RGB â€‹+ â€‹Thermal models were 66% and 64%, respectively. CONCLUSIONS: Although the low infection rate precluded the ability of our models to identify surgical site infections, we were able to generate two models to successfully segment wounds. This proof-of-concept study demonstrates that computer vision has the potential to support future surgical applications.

Addition of aspirin to venous thromboembolism chemoprophylaxis safely decreases venous thromboembolism rates in trauma patients.

Background: Trauma patients exhibit a multifactorial hypercoagulable state and have increased risk of venous thromboembolism (VTE). Despite early and aggressive chemoprophylaxis (CP) with various heparin compounds ("standard" CP; sCP), VTE rates remain high. In high-quality studies, aspirin has been shown to decrease VTE in postoperative elective surgical and orthopedic trauma patients. We hypothesized that inhibiting platelet function with aspirin as an adjunct to sCP would reduce the risk of VTE in trauma patients. Methods: We performed a retrospective observational study of prospectively collected data from all adult patients admitted to an American College of Surgeons Level I Trauma center from January 2012 to June 2015 to evaluate the addition of aspirin (sCP+A) to sCP regimens for VTE mitigation. Cox proportional hazard models were used to assess the potential benefit of adjunctive aspirin for symptomatic VTE incidence. Results: 10,532 patients, median age 44 (IQR 28 to 62), 68% male, 89% blunt mechanism of injury, with a median Injury Severity Score (ISS) of 12 (IQR 9 to 19), were included in the study. 8646 (82%) of patients received only sCP, whereas 1886 (18%) patients received sCP+A. The sCP+A cohort displayed a higher median ISS compared with sCP (13 vs 11; p<0.01). The overall median time of sCP initiation was hospital day 1 (IQR 0.8 to 2) and the median day for aspirin initiation was hospital day 3 (IQR 1 to 6) for the sCP+A cohort. 353 patients (3.4%) developed symptomatic VTE. Aspirin administration was independently associated with a decreased relative hazard of VTE (HR 0.57; 95% CI 0.36 to 0.88; p=0.01). There were no increased bleeding or wound complications associated with sCP+A (point estimate 1.23, 95% CI 0.68 to 2.2, p=0.50). Conclusion: In this large trauma cohort, adjunctive aspirin was independently associated with a significant reduction in VTE and may represent a potential strategy to safely mitigate VTE risk in trauma patients. Further prospective studies evaluating the addition of aspirin to heparinoid-based VTE chemoprophylaxis regimens should be sought. Level of evidence: Level III/therapeutic.

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.

Engineering Human Cells Expressing CRISPR/Cas9-Synergistic Activation Mediators for Recombinant Protein Production.

Recombinant engineering for protein production commonly employs plasmid-based gene templates for introduction and expression of genes in a candidate cell system in vitro. Challenges to this approach include identifying cell types that can facilitate proper post-translational modifications and difficulty expressing large multimeric proteins. We hypothesized that integration of the CRISPR/Cas9-synergistic activator mediator (SAM) system into the human genome would be a powerful tool capable of robust gene expression and protein production. SAMs are comprised of a "dead" Cas9 (dCas9) linked to transcriptional activators viral particle 64 (VP64), nuclear factor-kappa-B p65 subunit (p65), and heat shock factor 1 (HSF1) and are programmable to single or multiple gene targets. We integrated the components of the SAM system into human HEK293, HKB11, SK-HEP1, and HEP-g2 cells using coagulation factor X (FX) and fibrinogen (FBN) as proof of concept. We observed upregulation of mRNA in each cell type with concomitant protein expression. Our findings demonstrate the capability of human cells stably expressing SAM for user-defined singleplex and multiplex gene targeting and highlight their broad potential utility for recombinant engineering as well as transcriptional modulation across networks for basic, translational, and clinical modeling and applications.

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.

Rapid cold sterilization of 3D printed surgical instruments for the austere environment.

INTRODUCTION: Medical operations are vulnerable to global supply chain fluctuations. The ability to locally produce and reliably sterilize medical equipment may mitigate this risk. This project developed a reliable high-level disinfection process for 3D printed surgical tools. METHODS: Surgical instruments and consumables were designed and printed from various materials. Devices contaminated with known and unknown bacteria underwent one of three cleaning methods followed by high-level disinfection using submersion in a Cidex OPA Solution. Devices were then cultured on blood agar plates and incubated for 48 h. Positive and negative controls were performed. RESULTS: The results of control experiments showed no growth on negative controls and significant growth on all positive control plates. Of the three cleaning methods tested, one showed no growth: cleaning with isopropyl alcohol and chlorhexidine followed by Cidex bath. DISCUSSION: This project successfully developed a rapid high-level disinfection process for 3D printed surgical instruments made from two different types of 3D printing material.

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.

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.

Modern Statistical Methods for the Surgeon Scientist: The Clash of Frequentist versus Bayesian Paradigms.

The practice of evidence-based medicine is the result of a multitude of research and trials aimed toward improving health-care outcomes. An understanding of the associated data remains paramount toward optimizing patient outcomes. Medical statistics commonly revolve around frequentist concepts that are convoluted and nonintuitive for nonstatisticians. Within this article, we will discuss frequentist statistics, their limitations, as well as introduce Bayesian statistics as an alternative approach for data interpretation. By doing so, we intend to highlight the importance of correct statistical interpretations through clinically relevant examples while providing a deeper understanding of the underlying philosophies of frequentist and Bayesian statistics.

Impact of COVID on surgical case volume at military treatment facilities with surgical residencies.

INTRODUCTION: The Military Health System (MHS) is tasked with the dual mission of providing medical care to beneficiaries while ensuring medical readiness. MHS provides care through a combination of military treatment facilities (MTF) ("direct care"; DC) & off-base civilian facilities ("purchased care"; PC). Given recent concerns regarding low surgical volume at MTFs, we sought to evaluate COVID's impact on elective and non-elective case volume at MTFs with surgical residencies. METHODS: Retrospective review of 2017-2021 M2 database was performed on Tricare beneficiaries who underwent bariatric surgery or major colorectal surgery in the DC or PC market at, or, surrounding MTFs with surgical residencies. Procedures were identified using ICD-10 procedure codes and Medicare severity-diagnosis related groups. A detailed analysis was then performed on changes in case volume in the DC and PC markets. RESULTS: 5,698 bariatric and 5,517 major colorectal procedures were performed during the study period. There was an 84% vs 20% quarterly decrease in elective bariatric surgeries completed in the DC and PC markets from Q1 to Q2 2020. Pre to post-COVID (Q1 2017 - Q1 2020 vs Q3 2020 - Q4 2021) there was a decrease in the percentage of bariatric surgeries completed in the DC market (74.1% vs 55.0%, p = 0.001). Meanwhile, major colorectal surgery quarterly case volume remained unchanged in the DC (137 vs 125, p = 0.18) and PC (146 v 137, p = 0.13) markets, pre- and post-COVID. DISCUSSION: Bariatric surgical case volume at MTFs disproportionately decreased during COVID when compared to the PC market and major colorectal cases. Bariatric case volume has rebounded in PC markets surpassing pre-COVID levels while DC case volume remains depressed. Further attention is warranted regarding decreased elective surgical case volume at MTFs.

Use of Bayesian Statistics to Reanalyze Data From the Pragmatic Randomized Optimal Platelet and Plasma Ratios Trial.

Importance: Frequentist statistical approaches are the most common strategies for clinical trial design; however, bayesian trial design may provide a more optimal study technique for trauma-related studies. Objective: To describe the outcomes of bayesian statistical approaches using data from the Pragmatic Randomized Optimal Platelet and Plasma Ratios (PROPPR) Trial. Design, Setting, and Participants: This quality improvement study performed a post hoc bayesian analysis of the PROPPR Trial using multiple hierarchical models to assess the association of resuscitation strategy with mortality. The PROPPR Trial took place at 12 US level I trauma centers from August 2012 to December 2013. A total of 680 severely injured trauma patients who were anticipated to require large volume transfusions were included in the study. Data analysis for this quality improvement study was conducted from December 2021 and June 2022. Interventions: In the PROPPR Trial, patients were randomized to receive a balanced transfusion (equal portions of plasma, platelets, and red blood cells [1:1:1]) vs a red blood cell-heavy strategy (1:1:2) during their initial resuscitation. Main Outcomes and Measures: Primary outcomes from the PROPPR trial included 24-hour and 30-day all-cause mortality using frequentist statistical methods. Bayesian methods were used to define the posterior probabilities associated with the resuscitation strategies at each of the original primary end points. Results: Overall, 680 patients (546 [80.3%] male; median [IQR] age, 34 [24-51] years, 330 [48.5%] with penetrating injury; median [IQR] Injury Severity Score, 26 [17-41]; 591 [87.0%] with severe hemorrhage) were included in the original PROPPR Trial. Between the groups, no significant differences in mortality were originally detected at 24 hours (12.7% vs 17.0%; adjusted risk ratio [RR], 0.75 [95% CI, 0.52-1.08]; P = .12) or 30 days (22.4% vs 26.1%; adjusted RR, 0.86 [95% CI, 0.65-1.12]; P = .26). Using bayesian approaches, a 1:1:1 resuscitation was found to have a 93% (Bayes factor, 13.7; RR, 0.75 [95% credible interval, 0.45-1.11]) and 87% (Bayes factor, 6.56; RR, 0.82 [95% credible interval, 0.57-1.16]) probability of being superior to a 1:1:2 resuscitation with regards to 24-hour and 30-day mortality, respectively. Conclusions and Relevance: In this quality improvement study, a post hoc bayesian analysis of the PROPPR Trial found evidence in support of mortality reduction with a balanced resuscitation strategy for patients in hemorrhagic shock. Bayesian statistical methods offer probability-based results capable of direct comparison between various interventions and should be considered for future studies assessing trauma-related outcomes.

Validation of a miniaturized handheld arterial pressure monitor for guiding full and partial REBOA use during resuscitation.

PURPOSE: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a well-validated method for the control of noncompressible truncal hemorrhage. In lower resource or battlefield settings, the need for arterial line setup and monitoring is problematic and potentially prohibitive. We sought to evaluate the accuracy and precision of a miniaturized portable device (Centurion COMPASS®) versus standard arterial pressure monitoring using standard ER-REBOA and partial REBOA (pREBOA) as a high-fidelity and space-/time-conserving alternative. METHODS: A total of 40 swine underwent a four-phase validation/precision study (each phase using five ER-REBOAs and five pREBOAs). Phases I/II evaluated accuracy with full and pREBOA in uninjured animals. Phases III/IV duplicated the previous phases but in a severe hemorrhagic shock model. Carotid and femoral pressures were monitored with both intra-arterial pressure systems and the COMPASS® device. The vascular flow was measured by aortic flow probes. Correlation and Bland-Altman analysis were performed. RESULTS: There was a strong correlation in accuracy testing of proximal and distal COMPASS® devices compared to standard intra-arterial pressure monitoring (r = 0.94, 0.8; p < 0.005) as well as during precision testing (r = 0.98, 0.89 p < 0.005) in the uninjured phases. Similar accuracy and reliability were demonstrated in hemorrhagic shock, with a strong correlation for the proximal and distal COMPASS® devices (r = 0.98, 0.97; p < 0.005), as well as during precision testing (r = 0.99, 0.95; p < 0.005) in both full and pREBOA scenarios. Bland-Altman analysis showed extremely low bias between the COMPASS® and arterial line for both proximal (bias = 1.9) and distal (bias = 0.8) pressure measurements. CONCLUSION: The COMPASS® provides accurate and precise pressure measurements during standard and partial REBOA in both uninjured and shock conditions. This device may help extend and enhance capability in any low-resource/battlefield settings, or even eliminate the need for standard intra-arterial invasive pressure monitoring and external setup.

Utilization of Machine Learning Approaches to Predict Mortality in Pediatric Warzone Casualties.

BACKGROUND: Identification of pediatric trauma patients at the highest risk for death may promote optimization of care. This becomes increasingly important in austere settings with constrained medical capabilities. This study aimed to develop and validate predictive models using supervised machine learning (ML) techniques to identify pediatric warzone trauma patients at the highest risk for mortality. METHODS: Supervised learning approaches using logistic regression (LR), support vector machine (SVM), neural network (NN), and random forest (RF) models were generated from the Department of Defense Trauma Registry, 2008-2016. Models were tested and compared to determine the optimal algorithm for mortality. RESULTS: A total of 2,007 patients (79% male, median age range 7-12 years old, 62.5% sustaining penetrating injury) met the inclusion criteria. Severe injury (Injury Severity Score > 15) was noted in 32.4% of patients, while overall mortality was 7.13%. The RF and SVM models displayed recall values of .9507 and .9150, while LR and NN displayed values of .8912 and .8895, respectively. Random forest (RF) outperformed LR, SVM, and NN on receiver operating curve (ROC) analysis demonstrating an area under the ROC of .9752 versus .9252, .9383, and .8748, respectively. CONCLUSION: Machine learning (ML) techniques may prove useful in identifying those at the highest risk for mortality within pediatric trauma patients from combat zones. Incorporation of advanced computational algorithms should be further explored to optimize and supplement the diagnostic and therapeutic decision-making process.