Initial Hemorrhage Control Procedure for Splenic Injuries May Affect Risk of Venous Thromboembolism.

INTRODUCTION: Venous thromboembolism (VTE) continues to be a major cause of morbidity in trauma. It is unclear whether the type of hemorrhage control procedure (i.e., splenectomy versus angioembolization) is associated with an increased risk of VTE. We hypothesize that hemodynamically stable patients undergoing angioembolization for blunt high-grade splenic injuries have lower rates of VTE compared to those undergoing splenectomy. METHODS: The American College of Surgeons Trauma Quality Program dataset from 2017 to 2019 was queried to identify all patients with American Association for the Surgery of Trauma grade 3-5 blunt splenic injuries. Outcomes including VTE rates were compared between those who were managed with splenectomy versus angioembolization. Propensity score matching (1:1) was performed adjusting for age, sex, initial vital signs, Injury Severity Score, and splenic injury grade. RESULTS: The analysis included 4698 matched patients (splenectomy [n = 2349] and angioembolization [n = 2349]). The median (interquartile range) age was 41 (27-58) years and 69% were male. Patients were well matched between groups. Angioembolization was associated with significantly lower VTE than splenectomy (2.2% versus 3.4%, P = 0.010) despite less use of VTE chemoprophylaxis (70% versus 80%, P < 0.001), as well as a relative delay in initiation of chemoprophylaxis (44 h versus 33 h, P < 0.001). Hospital and intensive care unit length of stay and mortality were also significantly lower in the angioembolization group. CONCLUSIONS: Angioembolization is associated with a significantly lower incidence of VTE than splenectomy. Thus, angioembolization should be considered for initial management of hemodynamically stable patients with high-grade blunt splenic injuries in whom laparotomy is not otherwise indicated.

Advanced Surgical Skills for Exposure in Trauma (ASSET) course improves military surgeon confidence.

OBJECTIVE: Active duty military surgeons often have limited trauma surgery experience prior to deployment. Consequently, military-civilian training programs have been developed at high-volume trauma centers to evaluate and maintain proficiencies. Advanced Surgical Skills for Exposure in Trauma (ASSET) was incorporated into the predeployment curriculum at the Army Trauma Training Detachment in 2011. This is the first study to assess whether military surgeons demonstrated improved knowledge and increased confidence after taking ASSET. DESIGN: Retrospective cohort study. SETTING: Quaternary care hospital. PATIENTS AND PARTICIPANTS: Attending military surgeons who completed ASSET between July 2011 and October 2020. MAIN OUTCOME MEASURE(S): Pre- and post-course self-reported comfort level with procedures was converted from a five-point Likert scale to a percentage and compared using paired t-tests. RESULTS: In 188 military surgeons, the median time in practice was 3 (1-8) years, with specialties in general surgery (52 percent), orthopedic surgery (29 percent), trauma (7 percent), and other disciplines (12 percent). The completed self-evaluation response rate was 80 percent (n = 151). The self-reported comfort level for all body regions improved following course completion (p < 0.001): chest (27 percent), neck (23 percent), upper extremity (22 percent), lower extremity (21 percent), and abdomen/pelvis (19 percent). The overall score on the competency test improved after completion of ASSET, with averages increasing from 62 ± 18 percent pretest to 71 ± 13 percent post-test (p < 0.001). CONCLUSIONS: After taking the ASSET course, military surgeons demonstrated improved knowledge and increased confidence in the operative skills taught in the course. The ASSET course may provide sustainment of knowledge and confidence if used at regular intervals to maintain trauma skills and deployment readiness.

Survival of In-Hospital Cardiopulmonary Arrest in Trauma Patients.

INTRODUCTION: Relative to other hospitalized patients, trauma patients are younger with fewer comorbidities, but the incidence and outcomes of in-hospital cardiopulmonary arrest (IHCA) with cardiopulmonary resuscitation (CPR) in this population is unknown. Therefore, we aimed to investigate factors associated with survival in trauma patients after IHCA to test the hypothesis that compared to other hospitalized patients, trauma patients with IHCA have improved survival. METHODS: Retrospective review of the Trauma Quality Improvement Program database 2017 to 2019 for patients who had IHCA with CPR. Primary outcome was survival to hospital discharge. Secondary outcomes were in-hospital complications, hospital length of stay, intensive care unit length of stay, and ventilator days. Data were compared with univariate and multivariate analyses at P < 0.05. RESULTS: In 22,346,677 admitted trauma patients, 14,056 (0.6%) received CPR. Four thousand three hundred seventy-seven (31.1%) survived to discharge versus 26.4% in a national sample of all hospitalized patients (P < 0.001). In trauma patients, median age was 55 y, the majority were male (72.2%). Mortality was higher for females versus males (70.3% versus 68.3%, P = 0.026). Multivariate regression showed that older age 1.01 (95% confidence interval (CI) 1.01-1.02), Hispanic ethnicity 1.21 (95% CI 1.04-1.40), and penetrating trauma 1.51 (95% CI 1.32-1.72) were risk factors for mortality, while White race was a protective factor 0.36 (95% CI 0.14-0.89). CONCLUSIONS: This is the first study to show that the incidence of IHCA with CPR is approximately six in 1000 trauma admissions and 31% survive to hospital discharge, which is higher than other hospitalized patients. Age, gender, racial, and ethnic disparities also influence survival.

When is it safe to start thromboprophylaxis after splenic angioembolization?

BACKGROUND: Thromboprophylaxis after blunt splenic trauma is complicated by the risk of bleeding, but the risk after angioembolization is unknown. We hypothesized that earlier thromboprophylaxis initiation was associated with increased bleeding complications without mitigating venous thromboembolism events. METHODS: All blunt trauma patients who underwent splenic angioembolization within 24 hours of arrival were identified from the American College of Surgeons Trauma Quality Improvement Program datasets from 2017 to 2019. Cases with <24-hour length of stay, other serious injuries, and surgery before angioembolization were excluded. Venous thromboembolism was defined as deep vein thrombosis or pulmonary embolism. Bleeding complications were defined as splenic surgery, additional embolization, or blood transfusion after thromboprophylaxis initiation. Data were compared with χ2 analysis and multivariate logistic regression at P < .05. RESULTS: In 1,102 patients, 84% had American Association for the Surgery of Trauma grade III to V splenic injuries, and 73% received thromboprophylaxis. Splenic surgery after angioembolization was more common in those with thromboprophylaxis initiation within the first 24 hours (5.7% vs 1.7%, P = .007), whereas those with the initiation of thromboprophylaxis after 72 hours were more likely to have a pulmonary embolism (2.3% vs 0.2%, P = .001). Overall, venous thromboembolism increased considerably when thromboprophylaxis was initiated after day 3. In multivariate analysis, time to thromboprophylaxis initiation was associated with bleeding (odds ratio 0.74 [95% confidence interval 0.58-0.94]) and venous thromboembolism complications (odds ratio 1.5 [95% confidence interval 1.20-1.81]). CONCLUSION: This national study evaluates bleeding and thromboembolic risk to elucidate the specific timing of thromboprophylaxis after splenic angioembolization. Initiation of thromboprophylaxis between 24 and 72 hours achieves the safest balance in minimizing bleeding and venous thromboembolism risk, with 48 hours particularly serving as the ideal time for protocolized administration.

Management of lower extremity vascular injuries in pediatric trauma patients: 20-year experience at a level 1 trauma center.

Introduction: Pediatric lower extremity vascular injuries (LEVI) are rare but can result in significant morbidity. We aimed to describe our experience with these injuries, including associated injury patterns, diagnostic and therapeutic challenges, and outcomes. Methods: This was a retrospective review at a single level 1 trauma center from January 2000 to December 2019. Patients less than 18 years of age with LEVI were included. Demographics, injury patterns, clinical status at presentation, and intensive care unit (ICU) and hospital length of stay (LOS) were collected. Surgical data were extracted from patient charts. Results: 4,929 pediatric trauma patients presented during the 20-year period, of which 53 patients (1.1%) sustained LEVI. The mean age of patients was 15 years (range 1-17 years), the majority were Black (68%), male (96%), and most injuries were from a gunshot wound (62%). The median Glasgow Coma Scale score was 15, and the median Injury Severity Score was 12. The most commonly injured arteries were the superficial femoral artery (28%) and popliteal artery (28%). Hard signs of vascular injury were observed in 72% of patients and 87% required operative exploration. There were 36 arterial injuries, 36% of which were repaired with a reverse saphenous vein graft and 36% were repaired with polytetrafluoroethylene graft. One patient required amputation. Median ICU LOS was three days and median hospital LOS was 15 days. There were four mortalities. Conclusion: Pediatric LEVIs are rare and can result in significant morbidity. Surgical principles for pediatric vascular injuries are similar to those applied to adults, and this subset of patients can be safely managed in a tertiary specialized center. Level of evidence: Level IV, retrospective study.

Admission to a Verified Pediatric Trauma Center is Associated With Improved Outcomes in Severely Injured Children.

BACKGROUND: Previous studies have shown improved survival for severely injured adult patients treated at American College of Surgeons verified level I/II trauma centers compared to level III and undesignated centers. However, this relationship has not been well established in pediatric trauma centers (PTCs). We hypothesize that severely injured children will have lower mortality at verified level I/II PTCs compared to centers without PTC verification. METHODS: All patients 1-15 years of age with ISS >15 in the 2017-2019 American College of Surgeons Trauma Quality Programs (ACS TQP) dataset were reviewed. Patients with pre-hospital cardiac arrest, burns, and those transferred out for ongoing inpatient care were excluded. Logistic regression models were used to assess the effects of pediatric trauma center verification on mortality. RESULTS: 16,301 patients were identified (64 % male, median ISS 21 [17-27]), and 60 % were admitted to verified PTCs. Overall mortality was 6.0 %. Mortality at centers with PTC verification was 5.1 % versus 7.3 % at centers without PTC verification (p < 0.001). After controlling for injury mechanism, sex, age, pediatric-adjusted shock index (SIPA), ISS, arrival via interhospital transfer, and adult trauma center verification, pediatric level I/II trauma center designation was independently associated with decreased mortality (OR 0.72, 95 % CI 0.61-0.85). CONCLUSIONS: Treatment at ACS-verified pediatric trauma centers is associated with improved survival in critically injured children. These findings highlight the importance of PTC verification in optimizing outcomes for severely injured pediatric patients and should influence trauma center apportionment and prehospital triage. LEVEL OF EVIDENCE: Level IV - Retrospective review of national database.

Short Versus Long Antibiotic Duration for Necrotizing Soft Tissue Infection: A Systematic Review and Meta-Analysis.

Background: Necrotizing soft tissue infections (NSTIs) are rapidly spreading, life-threatening infections that require emergent surgical intervention with immediate antibiotic initiation. However, there is no consensus regarding duration of antibiotic therapy after source control. We hypothesized that a short course of antibiotic therapy is as effective as a long course of antibiotic therapy after final debridement for NSTI. Methods: A systematic review of the literature was performed using PubMed, Embase, and Cochrane Library from inception to November 2022. Observational studies comparing short (≤7 days) versus long (>7 days) antibiotic duration for NSTI were included. Primary outcome was mortality and secondary outcomes included limb amputation and Clostridium difficile infection (CDI). Cumulative analysis was performed with Fisher exact test. Meta-analysis was performed using a fixed effects model and heterogeneity was assessed using Higgins I2. Results: A total of 622 titles were screened and four observational studies evaluating 532 patients met inclusion criteria. Mean age was 52 years, 67% were male, 61% had Fournier gangrene. There was no difference in mortality when comparing short to long duration antibiotic agents on both cumulative analysis (5.6% vs. 4.0%; p = 0.51) and meta-analysis (relative risk, 0.9; 95% confidence interval, 0.8-1.0; I2 0; p = 0.19). There was no significant difference in rates of limb amputation (11% vs. 8.5%; p = 0.50) or CDI (20.8% vs. 13.3%; p = 0.14). Conclusions: Short duration antibiotic therapy may be as effective as longer duration antibiotic therapy for NSTI after source control. Further high-quality data such as randomized clinical trials are required to create evidence-based guidelines.

Burn excision within 48 hours portends better outcomes than standard management: A nationwide analysis.

BACKGROUND: Previous studies have debated the optimal time to perform excision and grafting of second- and third-degree burns. The current consensus is that excision should be performed before the sixth hospital day. We hypothesize that patients who undergo excision within 48 hours have better outcomes. METHODS: The American College of Surgeons Trauma Quality Programs data set was used to identify all patients with at least 10% total body surface area second- and third-degree burns from years 2017 to 2019. Patients with other serious injuries (any Abbreviated Injury Scale, >3), severe inhalational injury, prehospital cardiac arrest, and interhospital transfers were excluded. International Classification of Diseases, Tenth Revision , procedure codes were used to ascertain time of first excision. Patients who underwent first excision within 48 hours of admission (early excision) were compared with those who underwent surgery 48 to 120 hours from admission (standard therapy). Propensity score matching was performed to control for age and total body surface area burned. RESULTS: A total of 2,270 patients (72% male) were included in the analysis. The median age was 37 (23-55) years. Early excision was associated with shorter hospital length of stay (LOS), and intensive care unit LOS. Complications including deep venous thrombosis, pulmonary embolism, ventilator-associated pneumonia, and catheter-associated urinary tract infection were significantly lower with early excision. There was no significant difference in mortality. CONCLUSION: Performance of excision within 48 hours is associated with shorter hospital LOS and fewer complications than standard therapy. We recommend taking patients for operative debridement and temporary or, when feasible, permanent coverage within 48 hours. Prospective trials should be performed to verify the advantages of this treatment strategy. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level III.

Examining the Definition of Ventilator-Associated Pneumonia in the Trauma Setting: A Single-Center Analysis.

Background: Ventilator associated pneumonia (VAP) is defined by the American College of Surgeons Trauma Quality Improvement Program (ACS TQIP) using laboratory findings, pathophysiologic signs/symptoms, and imaging criteria. However, many critically ill trauma patients meet the non-specific laboratory and sign/symptom thresholds for VAP, so the TQIP designation of VAP depends heavily upon imaging evidence. We hypothesized that physician opinions widely vary regarding chest radiograph findings significant for VAP. Patients and Methods: The TQIP Spring 2021 Benchmark Report (BR) was used to identify 14 patients with VAP at an academic Level 1 Trauma Center. Critically ill trauma patients (n = 7) who spent at least four days intubated and met TQIP's laboratory and sign/symptom thresholds for VAP but did not appear as VAPs on the BR comprised the control group. For each deidentified patient, four successive chest radiographic images were compiled and arranged chronologically. Cases and controls were randomly arranged in digital format. Blinded physicians (n = 27) were asked to identify patients with VAP based solely on imaging evidence. Results: Radiographic evidence of VAP was highly subjective (Krippendorff α = 0.134). Among physicians of the same job description, inter-rater reliability remained low (α = 0.137 for trauma attending physicians; α = 0.141 for trauma fellows; α = 0.271 for radiologists). When majority judgment was compared to the TQIP BR, there was disagreement between the two tests (Cohen κ = -0.071; sensitivity, 64.3%; specificity, 28.6%). Conclusions: Current definitions of VAP rely on subjective imaging interpretation and ignore the reality that there are numerous explanations for opacities on CXR. The inconsistency of physicians' imaging interpretation and protean physiologic findings for VAP in trauma patients should preclude the current definition of VAP from being used as a quality improvement metric in TQIP.

Improved survival for severely injured patients receiving massive transfusion at US teaching hospitals: A nationwide analysis.

BACKGROUND: Previous studies have shown improved survival for patients treated at American College of Surgeons (ACS)-verified level I trauma centers compared with level II, level III, and undesignated centers. This mortality difference is more pronounced in severely injured patients. However, a survival benefit for severely injured trauma patients has not been established at teaching institutions compared with nonteaching centers. Because massive transfusion (MT) is associated with high mortality, we hypothesize that patients receiving MT have lower mortality at teaching hospitals than at nonteaching hospitals. METHODS: All adult ACS Trauma Quality Improvement Program-eligible patients who underwent MT, defined as >10 U of packed red blood cells in the first 4 hours after arrival, in the 2019 ACS Trauma Quality Programs participant use file were eligible. Patients with severe head injury (head Abbreviated Injury Scale score, ≥3), prehospital cardiac arrest, and interhospital transfers were excluded. Logistic regression models were used to assess the effects of trauma center hospital teaching status on the adjusted odds of 3-hour, 6-hour, and 24-hour mortality. RESULTS: A total of 1,849 patients received MT (81% male; median Injury Severity Score, 26 [18-35]), 72% were admitted to level I trauma centers, and 28% were admitted to level II centers. Overall hospital mortality was 41%; 17% of patients died in 3 hours, 25% in 6 hours, and 33% in 24 hours. Teaching hospitals were associated with decreased 3-hour (odds ratio [OR], 0.45; 95% confidence interval [CI], 0.27-0.75), 6-hour (OR, 0.37; 95% CI, 0.24-0.56), 24-hour (OR, 0.50; 95% CI, 0.34-0.75), and overall mortality (OR, 0.66; 95% CI, 0.44-0.98), compared with nonteaching hospitals, controlling for sex, age, heart rate, injury severity, injury mechanism, and trauma center verification level. CONCLUSION: Severely injured patients requiring MT experience significantly lower mortality at teaching hospitals compared with nonteaching hospitals, independently of trauma center verification level. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level III.

Illuminating the Use of Trauma Whole-Body CT Scan During the Global Contrast Shortage.

BACKGROUND: Use of whole-body CT scan (WBCT) is widespread in the evaluation of traumatically injured patients and may be associated with improved survival. WBCT protocols include the use of IV contrast unless there is a contraindication. This study tests the hypothesis that using plain WBCT scan during the global contrast shortage would result in greater need for repeat contrast-enhanced CT, but would not impact mortality, missed injuries, or rates of acute kidney injury (AKI). STUDY DESIGN: All trauma encounters at an academic level-I trauma center between March 1, 2022 and June 24, 2022, excluding burns and prehospital cardiac arrests, were reviewed. Imaging practices and outcomes before and during contrast shortage (beginning May 3, 2022) were compared. RESULTS: The study population included 1,109 consecutive patients (72% male), with 890 (80%) blunt and 219 (20%) penetrating traumas. Overall, 53% of patients underwent WBCT and contrast was administered to 73%. The overall rate of AKI was 6% and the rate of renal replacement therapy (RRT) was 1%. Contrast usage in WBCT was 99% before and 40% during the shortage (p < 0.001). There was no difference in the rate of repeat CT scans, missed injuries, AKI, RRT, or mortality. CONCLUSIONS: Trauma imaging practices at our center changed during the global contrast shortage; the use of contrast decreased despite the frequency of trauma WBCT scans remaining the same. The rates of AKI and RRT did not change, suggesting that WBCT with contrast is insufficient to cause AKI. The missed injury rate was equivalent. Our data suggest similar outcomes can be achieved with selective IV contrast use during WBCT.

Do all cardiac surgery patients benefit from antifibrinolytic therapy?

BACKGROUND: In trauma patients, the recognition of fibrinolysis phenotypes has led to a re-evaluation of the risks and benefits of antifibrinolytic therapy (AF). Many cardiac patients also receive AF, but the distribution of fibrinolytic phenotypes in that population is unknown. The purpose of this hypothesis-generating study was to fill that gap. METHODS: Seventy-eight cardiac surgery patients were retrospectively reviewed. Phenotypes were defined as hypofibrinolytic (LY30 <0.8%), physiologic (0.8%-3.0%), and hyperfibrinolytic (>3%) based on thromboelastogram. RESULTS: The population was 65 ± 10-years old, 74% male, average body mass index of 29 ± 5 kg/m2 . Fibrinolytic phenotypes were distributed as physiologic = 45% (35 of 78), hypo = 32% (25 of 78), and hyper = 23% (18 of 78). There was no obvious effect of age, gender, race, or ethnicity on this distribution; 47% received AF. For AF versus no AF, the time with chest tube was longer (4 [1] vs. 3 [1] days, p = .037), and all-cause morbidity was more prevalent (51% vs. 25%, p = .017). However, when these two groups were further stratified by phenotypes, there were within-group differences in the percentage of patients with congestive heart failure (p = .022), valve disease (p = .024), on-pump surgery (p < .0001), estimated blood loss during surgery (p = .015), transfusion requirement (p = .015), and chest tube output (p = .008), which highlight other factors along with AF that might have affected all-cause morbidity. CONCLUSION: This is the first description of the prevalence of three different fibrinolytic phenotypes and their potential influence on cardiac surgery patients. The use of AF was associated with increased morbidity, but because of the small sample size and treatment allocation bias, additional confirmatory studies are necessary. We hope these present findings open the dialog on whether it is safe to administer AFs to cardiac surgery patients who are normo- or hypofibrinolytic.

The Key to Combat Readiness Is a Strong Military-Civilian Partnership.

INTRODUCTION: In peacetime, it is challenging for Army Forward Resuscitative Surgical Teams (FRST) to maintain combat readiness as trauma represents <0.5% of military hospital admissions and not all team members have daily clinical responsibilities. Military surgeon clinical experience has been described, but no data exist for other members of the FRST. We test the hypothesis that the clinical experience of non-physician FRST members varies between active duty (AD) and Army reservists (AR). METHODS: Over a 3-year period, all FRSTs were surveyed at one civilian center. RESULTS: Six hundred and thirteen FRST soldiers were provided surveys and 609 responded (99.3%), including 499 (81.9%) non-physicians and 110 (18.1%) physicians/physician assistants. The non-physician group included 69% male with an average age of 34 ± 11 years and consisted of 224 AR (45%) and 275 AD (55%). Rank ranged from Private to Colonel with officers accounting for 41%. For AD vs. AR, combat experience was similar: 50% vs. 52% had ≥1 combat deployment, 52% vs. 60% peri-deployment patient load was trauma-related, and 31% vs. 32% had ≥40 patient contacts during most recent deployment (all P > .15). However, medical experience differed for AD and AR: 18% vs. 29% had >15 years of experience in practice and 4% vs. 17% spent >50% of their time treating critically injured patients (all P < .001). These differences persisted across all specialties, including perioperative nurses, certified registered nurse anesthetists, operating room (OR) techs, critical-care nurses, emergency room (ER) nurses, licensed practical nurse (LPN), and combat medics. CONCLUSIONS: This is the first study of clinical practice patterns in AD vs. AR, non-physician members of Army FRSTs. In concordance with previous studies of military surgeons, FRST non-physicians seem to be lacking clinical experience as well. To maintain readiness and to provide optimal care for our injured warriors, the entire FRST, not just individuals, should embed within civilian centers.

Acute Kidney Injury Risk in Patients Treated with Vancomycin Combined with Meropenem or Cefepime.

Background: No previous studies have determined the incidence of acute kidney injury (AKI) in trauma patients treated with vancomycin + meropenem (VM) versus vancomycin + cefepime (VC). The purpose of this study was to fill this gap. Methods: A series of 99 patients admitted to an American College of Surgeons-verified level 1 trauma center over a two-year period who received VC or VM for >48 hours were reviewed retrospectively. Exclusion criteria were existing renal dysfunction or on renal replacement therapy. The primary outcome was AKI as defined by a rise in serum creatinine (SCr) to 1.5 times baseline. Multi-variable analysis was performed to control for factors associated with AKI (age, obesity, gender, length of stay [LOS], nephrotoxic agent(s), and baseline SCr), with significance defined as p < 0.05. Results: The study population was 50 ± 19 years old, 76% male, with a median LOS of 21 [range 15-39] days, and baseline SCr of 0.9 ± 0.2 mg/dL. Antibiotics, diabetes mellitus, and Injury Severity Score were independent predictors of AKI (odds ratio [OR] 4.4; 95% confidence interval [CI] 1.4-12; OR 9.3; 95% CI 1-27; OR 1.2; 95% CI 1.023-1.985, respectively). The incidence of AKI was higher with VM than VC (10/26 [38%] versus 14/73 [19.1%]; p = 0.049). Conclusions: The renal toxicity of vancomycin is potentiated by meropenem relative to cefepime in trauma patients. We recommend caution when initiating vancomycin combination therapy, particularly with meropenem.

Heart Rate Complexity in US Army Forward Surgical Teams During Pre Deployment Training.

INTRODUCTION: For trauma triage, the US Army has developed a portable heart rate complexity (HRC) monitor, which estimates cardiac autonomic input and the activity of the hypothalamic-pituitary-adrenal (HPA) axis. We hypothesize that autonomic/HPA stress associated with predeployment training in U.S. Army Forward Surgical Teams will cause changes in HRC. MATERIALS AND METHODS: A prospective observational study was conducted in 80 soldiers and 10 civilians at the U.S. Army Trauma Training Detachment. Heart rate (HR, b/min), cardiac output (CO, L/min), HR variability (HRV, ms), and HRC (Sample Entropy, unitless), were measured using a portable non-invasive hemodynamic monitor during postural changes, a mass casualty (MASCAL) situational training exercise (STX) using live tissue, a mock trauma (MT) STX using moulaged humans, and/or physical exercise. RESULTS: Baseline HR, CO, HRV, and HRC averaged 72 ± 11b/min, 5.6 ± 1.2 L/min, 48 ± 24 ms, and 1.9 ± 0.5 (unitless), respectively. Supine to sitting to standing caused minimal changes. Before the MASCAL or MT, HR and CO both increased to ~125% baseline, whereas HRV and HRC both decreased to ~75% baseline. Those values all changed an additional ~5% during the MASCAL, but an additional 10 to 30% during the MT. With physical exercise, HR and CO increased to >200% baseline, while HRV and HRC both decreased to 40 to 60% baseline; these changes were comparable to those caused by the MT. All the changes were P < 0.05. CONCLUSIONS: Various forms of HPA stress during Forward Surgical Team STXs can be objectively quantitated continuously in real time with a portable non-invasive monitor. Differences from resting baseline indicate stress anticipating an impending STX whereas differences between average and peak responses indicate the relative stress between STXs. Monitoring HRC could prove useful to field commanders to rapidly and objectively assess the readiness status of troops during STXs or repeated operational missions. In the future, health care systems and regulatory bodies will likely be held accountable for stress in their trainees and/or obliged to develop wellness options and standardize efforts to ameliorate burnout, so HRC metrics might have a role, as well.

The unborn fetus: The unrecognized victim of trauma during pregnancy.

BACKGROUND: Trauma is the leading cause of non-obstetric death in pregnancy. While maternal management is defined, few studies have examined the effects on the fetus. METHODS: Following IRB approval, all pregnant females (2010-2017) at a level-1 trauma center were retrospectively reviewed. Maternal and fetal demographics, interventions, and clinical outcomes were analyzed. RESULTS: There were 188 pregnancies in 5654 females. Maternal demographics were 26 ±â€¯7 years old, gestational age at trauma 21 ±â€¯12 weeks, 81% blunt mechanism, and maternal mortality 6%. Forty-one (22%) fetuses were immediately affected by the trauma including 20 (11%) born alive, 12 (7%) fetal demise, and 9 (5%) stillbirths. Of those that initially survived (n = 20), 5 (25%) expired during neonatal hospitalization. Two mothers returned immediately after trauma discharge with stillbirths for an overall infant mortality of 14% (n = 26). There were 84 patients with complete data to delivery including the 41 born at trauma and 43 born on a subsequent hospitalization. Those born at the time of trauma had significantly more delivery/neonatal complications and worse outcomes. Overall trauma burden to the fetus (preterm delivery, stillbirth, delivery/neonatal complication, or long-term disability) was 66% (56/84). CONCLUSIONS: Trauma during pregnancy has significant immediate mortality and delayed effects on the unborn fetus. This study has uncovered a previously hidden burden and mortality of trauma during pregnancy. LEVEL OF EVIDENCE: Level III.

Exercise-Induced Changes in Compensatory Reserve and Heart Rate Complexity.

BACKGROUND: Portable noninvasive Heart Rate Complexity (HRC) and Compensatory Reserve Measurement (CRM) monitors have been developed to triage supine combat casualties. Neither monitor has been tested in upright individuals during physical exercise. This study tests the hypothesis that exercise evokes proportional changes in HRC and CRM.METHODS: Two instruments monitored volunteers (9 civilian and 11 soldiers) from the Army Trauma Training Department (ATTD) before, during, and following physical exercise. One recorded heart rate (HR, bpm), cardiac output (CO, L · min-1), heart rate variability (HRV, root mean square of successive differences, ms), and HRC (Sample Entropy, unitless). The other recorded HR, pulse oximetry (Spo2, %), and CRM (%).RESULTS: Baseline HR, CO, HRV, HRC, and CRM averaged 72 ± 1 bpm, 5.6 ± 1.2 L · min-1, 48 ± 24 ms, 1.9 ± 0.5, and 85 ± 10% in seated individuals. Exercise evoked peak HR and CO at > 200% of baseline, while HRC and CRM were simultaneously decreased to minimums that were ≤ 50% of baseline (all P < 0.001). HRV changes were variable and unreliable. Spo2 remained consistently above 95%. During a 60 min recovery, HR and CRM returned to baseline on parallel tracks (t1/2=11 ± 8 and 18 ± 14 min), whereas HRC recovery was slower than either CRM or HR (t1/2=40 ± 18 min, both P < 0.05).DISCUSSION: Exercise evoked qualitatively similar changes in CRM and HRC. CRM recovered incrementally faster than HRC, suggesting that vasodilation, muscle pump, and respiration compensate faster than cardiac autonomic control in young, healthy volunteers. Both HRC and CRM appear to provide reliable, objective, and noninvasive metrics of human performance in upright exercising individuals.Mulder MB, Eidelson SA, Buzzelli MD, Gross KR, Batchinsky AI, Convertino VA, Schulman CI, Namias N, Proctor KG. Exercise-induced changes in compensatory reserve and heart rate complexity. Aerosp Med Hum Perform. 2019; 90(12):1009-1015.