TXA (Tranexamic Acid) Risk Evaluation in Combat Casualties (TRECC).

BACKGROUND: The use of tranexamic acid (TXA) has become increasingly prevalent for hemorrhage prevention in military trauma patients due to its known survival benefits. There is concern of increased venous thromboembolism (VTE) subsequent to receiving TXA. The purpose of this retrospective study was to determine the rate of VTE in severely injured military personnel during Operation Enduring Freedom (2009-2014). METHODS: An analysis of 859 military trauma patients from the 2009-2014 Department of Defense Trauma Registry included subjects with an injury severity score (ISS) >10 and a massive transfusion (MT) (>10 units of blood products in the first 24 hours). Outcomes included a documented VTE (eg, deep vein thrombosis (DVT) or pulmonary embolism (PE)) during the patient's hospital course. Comparison between those who did/did not receive TXA was analyzed using three separate multiple regression analyses using listwise deletion, systematic replacement and multiple imputation. RESULTS: Subjects (n=620) met inclusion criteria with 27% (n=169) having a documented VTE. A total of 30% that received TXA had a documented VTE, 26% that did not receive TXA had a documented VTE and 43% (n=264, n=620) of the sample did not have TXA documented as either given or not given. Multiple regression analyses using listwise deletion and systematic replacement of the TXA variable demonstrated no difference in odds of VTE, whereas the multiple imputation analysis demonstrated a 3% increased odds of VTE, a9.4% increased odds of PE and 8.1% decreased odds of DVT with TXA administration. DISCUSSION: TXA use with an ISS >10 and MT resuscitation had a 3% increased odds of VTE and an increased odds of PE, whereas the odds of DVT were found to be decreased after multiple imputation analysis. Further research on the long-term risks and benefits of TXA usage in the military population is recommended. LEVEL OF EVIDENCE: IV-therapeutic.

Predictive survival factors of the traumatically injured on venovenous extracorporeal membrane oxygenation: A Bayesian model.

BACKGROUND: Venovenous extracorporeal membrane oxygenation (ECMO) has had encouraging evidence suggesting efficacy and acceptable safety in trauma patients with refractory respiratory failure. Given the obstacles of accruing adequate quality prospective data for a resource-intensive modality, it is unclear what is indicative of survival to discharge. We investigate pre-ECMO characteristics (age, Injury Severity Score [ISS], time from admission to cannulation, P:F ratio) in trauma patients to determine correlation with survival. METHODS: To address these challenges, we use Bayesian inference and patients from a level I trauma center and Extracorporeal Life Support Organization-designated Gold Center of Excellence (N = 12), published literature, and Markov chain Monte Carlo simulation to determine if there is strong predictive probability regarding survival to discharge. RESULTS: Bayesian inference probabilities expressed as odds ratios with 95% credible intervals (CrIs) were as follows: age (e = 0.981; CrI, 0.976-0.985), ISS (e = 0.996; CrI, 0.980-1.012), P:F ratio (e = 1.000; CrI, 0.996-1.003), and time from admission to ECMO (e = 0.988; CrI, 0.974-1.004). Bayes factors (BF) were as follows: BFage = 3.151, BFISS = 3.564 × 10, BFpf = 0.463, and BFtime = 913.758. CONCLUSION: Age was the only pre-ECMO factor that demonstrated the most certain effect on hospital mortality for trauma patients placed on venovenous ECMO. The ISS and time to ECMO initiation had some appreciable impact on survival although less certain than age; P:F ratio likely had none. However, the pre-ECMO factors that were found to have any impact on mortality were relatively diminutive. More studies are necessary to update prior distributions and enhance accuracy. LEVEL OF EVIDENCE: Prognostic, Level IV.

Preinjury statin use and thromboembolic events in trauma: a 10-year retrospective evaluation.

BACKGROUND: Traumatic injury is well known to increase the risk of venous thromboembolic events (VTEs), occurring in up to 58% of trauma patients. Statin medications have significant anti-inflammatory properties and have been shown to reduce the risk of VTE. We hypothesized that trauma patients who received statin medication before injury would have a lower incidence of VTE after injury. METHODS: A 10-y retrospective review identified all patients admitted to our trauma service with an injury severity score >9 and an intensive care unit stay of >3 d. This population was categorized as either "statin recipient" (SR) or "statin naïve," with subsequent categorical division by occurrence of VTE. Our primary outcome measure was the occurrence of documented VTE in both statin naïve and SR subjects. RESULTS: A total of 2519 trauma patients were included with 97 (3.8%) developing VTE. Pretrauma statin use in males remained as an independent predictor of VTE (odds ratio = 2.25, 95% confidence interval = 1.25-4.04, P < 0.01). The median time to VTE onset was 3 d longer in SRs (10.0 d; confidence interval = 7.3-12.7, P < 0.05). CONCLUSIONS: Pretrauma statin use does not appear to have a protective benefit of VTE prevention in trauma patients, as we have shown pretrauma SR male trauma patients to have a twofold increased incidence of VTE. However, when considering the 3 d longer median time to VTE onset found in SRs, we consider the protective benefit of statin use reported in the current literature as likely attributable to this observed delayed onset.

Multicenter evaluation of temporary intravascular shunt use in vascular trauma.

BACKGROUND: The indications and outcomes associated with temporary intravascular shunting (TIVS) for vascular trauma in the civilian sector are poorly understood. The objective of this study was to perform a contemporary multicenter review of TIVS use and outcomes. METHODS: Patients sustaining vascular trauma, requiring TIVS insertion (January 2005 to December 2013), were retrospectively identified at seven Level I trauma centers. Clinical demographics, operative details, and outcomes were abstracted. RESULTS: A total of 213 injuries (2.7%; 94.8% arterial) requiring TIVS were identified in 7,385 patients with vascular injuries. Median age was 27.0 years (range, 4-89 years), 91.0% were male, Glasgow Coma Scale (GCS) score was 15.0 (interquartile range, 4.0), Injury Severity Score (ISS) was 16.0 (interquartile range, 15.0), 26.0% had an ISS of 25 or greater, and 71.1% had penetrating injuries. The most common mechanism was gunshot wound (62.7%), followed by auto versus pedestrian (11.4%) and motor vehicle collision (6.5%). Shunts were placed for damage control in 63.4%, staged repair for combined orthopedic and vascular injuries in 36.1%, and for insufficient surgeon skill set in 0.5%. The most common vessel shunted was the superficial femoral artery (23.9%), followed by popliteal artery (18.8%) and brachial artery (13.2%). An argyle shunt (81.2%) was the most common conduit, followed by Pruitt-Inahara (9.4%). Dwell time was less than 6 hours in 61.4%, 24 hours in 86.5%, 48 hours in 95.9%, with only 4.1% remaining in place for more than 48 hours. Of the patients, 81.6% survived to definitive repair, and 79.6% survived overall. Complications included shunt thrombosis (5.6%) and dislodgment (1.4%). There was no association between dwell time and shunt thrombosis. The use of a noncommercial shunt (chest tube/feeding tube) did not impact shunt thrombosis but was an independent risk factor for subsequent graft failure. The limb salvage rate was 96.3%. No deaths could be attributed to a shunt complication. CONCLUSION: In the largest civilian TIVS experience insertion to date, both damage control and staged orthopedic vascular injuries were common indications for shunting. With an acceptable complication burden and no associated mortality attributed to this technique, shunting should be considered a viable treatment option. LEVEL OF EVIDENCE: Therapeutic study, level V.

A multi-institutional analysis of prehospital tourniquet use.

BACKGROUND: Recent military studies demonstrated an association between prehospital tourniquet use and increased survival. The benefits of this prehospital intervention in a civilian population remain unclear. The aims of our study were to evaluate tourniquet use in the civilian population and to compare outcomes to previously published military experience. We hypothesized that incorporation of tourniquet use in the civilian population will result in an overall improvement in mortality. METHODS: This is a preliminary multi-institutional retrospective analysis of prehospital tourniquet (MIA-T) use of patients admitted to nine urban Level 1 trauma centers from January 2010 to December 2013. Patient demographics and mortality from a previous military experience by Kragh et al. (Ann Surg. 2009;249:1-7) were used for comparison. Patients younger than 18 years or with nontraumatic bleeding requiring tourniquet application were excluded. Data were analyzed using a two-tailed unpaired Student's t test with p < 0.05 as significant. RESULTS: A total of 197 patients were included. Tourniquets were applied effectively in 175 (88.8%) of 197 patients. The average Injury Severity Score (ISS) for MIA-T versus military was 11 ± 12.5 versus 14 ± 10.5, respectively (p = 0.02). The overall mortality and limb amputation rates for the MIA-T group were significantly lower than previously seen in the military population at 6 (3.0%) of 197 versus 22 (11.3%) of 194 (p = 0.002) and 37 (18.8%) of 197 versus 97 (41.8%) of 232 (p = 0.0001), respectively. CONCLUSION: Our study is the largest evaluation of prehospital tourniquet use in a civilian population to date. We found that tourniquets were applied safely and effectively in the civilian population. Adaptation of this prehospital intervention may convey a survival benefit in the civilian population. LEVEL OF EVIDENCE: Epidemiologic study, level V.

MEDEVAC: survival and physiological parameters improved with higher level of flight medic training.

OBJECTIVE: Determine if a higher level of Army flight medic (AFM) training was associated with improved physiological state on arrival to a combat support hospital (CSH). METHODS: A retrospective study comparing casualties who were evacuated by two AFM units with only Emergency Medical Technicians-Basic (EMT-Bs) to an Army National Guard unit with Critical Care Flight Paramedics (CCFPs) in Afghanistan with an injury severity score >16 in different time periods looking at their 48-hour mortality, hematocrit (HCT), base deficit (BD), oxygen saturation (SpO2), and physiological parameters on arrival to the CSH. RESULTS: The CCFP group had better HCT [36.5 (8.8)] than the EMT-B group [33.1 (11.4); p ≤ 0.001]. BD and SpO2 were better in the CCFP group [-3.2 (4.7)]/[97.8 (4.8)] than the EMT-B group [-4.4 (5.5)]/[96.3 (10.9)] [p ≤ 0.014]. The CCFP group had a 72% lower estimated risk ratio of mortality with an associated improvement in 48-hour survivability of 4.9% versus 15.8% for the EMT-B-group. CONCLUSIONS: There is a statistically significant improvement in the HCT, BD, SpO2, and 48-hour survivability at the CSH in the cohort transported by the CCFP group when compared to the cohort transported by the EMT-B group.

Risk factors for hypotension in urgently intubated burn patients.

BACKGROUND: When urgently intubating patient in the burn intensive care unit (BICU), various induction agents, including propofol, are utilized that may induce hemodynamic instability. METHODS: A retrospective review was performed of consecutive critically ill burn patients who underwent urgent endotracheal intubation in BICU. Basic burn-related demographic data, indication for intubation, and induction agents utilized were recorded. The primary outcomes of interest were clinically significant hypotension requiring immediate fluid resuscitation, initiation or escalation of vasopressors immediately after intubation. Secondary outcomes included ventilator days, stay length, and in-hospital mortality. RESULTS: Between January 2003 and August 2010, we identified 279 urgent intubations in 204 patients. Of these, the criteria for presumed sepsis were met in 60% (n=168) of the intubations. After intubation, 117 patients (42%) experienced clinically significant hypotension. Propofol (51%) was the most commonly utilized induction agent followed by etomidate (23%), ketamine (15%), and midazolam (11%). On multiple logistic regression, %TBSA (OR 1.016, 95% CI 1.004-1.027, p<0.001) and presumed sepsis (OR 1.852, 95% CI 1.100-3.117, p=0.02) were the only significant predictors of hypotension. None of the induction agents, including propofol, were significantly associated with hypotension in patients with or without presumed sepsis. CONCLUSIONS: In critically ill burn patients undergoing urgent endotracheal intubation, specific induction agents, including propofol, were not associated with clinically significant hypotension. Presumed sepsis and %TBSA were the most important risk factors.