AAST multicenter prospective analysis of prehospital tourniquet use for extremity trauma.

BACKGROUND: Tourniquet use for extremity hemorrhage control has seen a recent increase in civilian usage. Previous retrospective studies demonstrated that tourniquets improve outcomes for major extremity trauma (MET). No prospective study has been conducted to date. The objective of this study was to evaluate outcomes in MET patients with prehospital tourniquet use. We hypothesized that prehospital tourniquet use in MET decreases the incidence of patients arriving to the trauma center in shock. METHODS: Data were collected prospectively for adult patients with MET at 26 Level I and 3 Level II trauma centers from 2015 to 2020. Limbs with tourniquets applied in the prehospital setting were included in the tourniquet group and limbs without prehospital tourniquets were enrolled in the control group. RESULTS: A total of 1,392 injured limbs were enrolled with 1,130 tourniquets, including 962 prehospital tourniquets. The control group consisted of 262 limbs without prehospital tourniquets and 88 with tourniquets placed upon hospital arrival. Prehospital improvised tourniquets were placed in 42 patients. Tourniquets effectively controlled bleeding in 87.7% of limbs. Tourniquet and control groups were similarly matched for demographics, Injury Severity Score, and prehospital vital signs (p > 0.05). Despite higher limb injury severity, patients in the tourniquet group were less likely to arrive in shock compared with the control group (13.0% vs. 17.4%, p = 0.04). The incidence of limb complications was not significantly higher in the tourniquet group (p > 0.05). CONCLUSION: This study is the first prospective analysis of prehospital tourniquet use for civilian extremity trauma. Prehospital tourniquet application was associated with decreased incidence of arrival in shock without increasing limb complications. We found widespread tourniquet use, high effectiveness, and a low number of improvised tourniquets. This study provides further evidence that tourniquets are being widely and safely adopted to improve outcomes in civilians with MET. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level IV.

Validating clinical threshold values for a dashboard view of the compensatory reserve measurement for hemorrhage detection.

BACKGROUND: Compensatory reserve measurement (CRM) is a novel noninvasive monitoring technology designed to assess physiologic reserve using feature interrogation of arterial pulse waveforms. This study was conducted to validate clinically relevant CRM values with a simplified color-coded dashboard view. METHODS: We performed a prospective observational study of 300 injured patients admitted to a level I trauma center. Compensatory reserve measurement was recorded upon emergency department admission. Data collected to complement the analysis included patient demographics, vital signs, lifesaving interventions, Injury Severity Score (ISS), and outcomes. Threshold values of CRM were analyzed for predictive capability of hemorrhage. RESULTS: A total of 285 patients met the inclusion criteria. Mean age of the population was 47 years, and 67% were male. Hemorrhage was present in 32 (11%), and lifesaving intervention was performed in 40 (14%) patients. Transfusion of packed red blood cells was administered in 33 (11.6%) patients, and 21 (7.4%) were taken to the operating room for surgical or endovascular control of hemorrhage. Statistical analyses were performed to identify optimal threshold values for three zones of CRM to predict hemorrhage. Optimal levels for red, yellow, and green areas of the dashboard view were stratified as follows: red if CRM was less than 30%, yellow if CRM was 30% to 59%, and green if CRM was 60% or greater. Odds of hemorrhage increased by 12-fold (odds ratio, 12.2; 95% confidence interval, 3.8-38.9) with CRM less than 30% (red) and 6.5-fold (odds ratio, 6.5; 95% confidence interval, 2.7-15.9) with CRM of equal to 30% to 59% (yellow) when compared with patients with CRM of 60% or greater. The area under the receiver operating characteristic curve for three-zone CRM was similar to that of continuous CRM (0.77 vs. 0.79) but further increased the ability to predict hemorrhage after adjusting for ISS (area under the receiver operating characteristic curve, 0.87). CONCLUSION: A three-zone CRM could be a potentially useful predictor of hemorrhage in trauma patients with added capabilities of continuous monitoring and a real-time ISS assessment. These data substantiate easily interpretable threshold dashboard values for triage with potential to improve injury outcomes. LEVEL OF EVIDENCE: Diagnostic, level II.

Limitations of multidetector computed tomography angiography for the diagnosis of blunt cerebrovascular injury.

OBJECTIVE Blunt cerebrovascular injuries (BCVIs) following trauma carry risk for morbidity and mortality. Since patients with BCVI are often asymptomatic at presentation and neurological sequelae often occur within 72 hours, timely diagnosis is essential. Multidetector CT angiography (CTA) has been shown to be a noninvasive, cost-effective, reliable means of screening; however, the false-positive rate of CTA in diagnosing patients with BCVI represents a key drawback. Therefore, the authors assessed the role of DSA in the screening of BCVI when utilizing CTA as the initial screening modality. METHODS The authors performed a retrospective analysis of patients who experienced BCVI between 2013 and 2015 at 2 Level I trauma centers. All patients underwent CTA screening for BCVI according to the updated Denver Screening Criteria. Patients who were diagnosed with BCVI on CTA underwent confirmatory digital subtraction angiography (DSA). Patient demographics, screening indication, BCVI grade on CTA and DSA, and laboratory values were collected. Comparison of false-positive rates stratified by BCVI grade on CTA was performed using the chi-square test. RESULTS A total of 140 patients (64% males, mean age 50 years) with 156 cerebrovascular blunt injuries to the carotid and/or vertebral arteries were identified. After comparison with DSA findings, CTA findings were incorrect in 61.5% of vessels studied, and the overall CTA false-positive rates were 47.4% of vessels studied and 47.9% of patients screened. The positive predictive value (PPV) for CTA was higher among worse BCVI subtypes on initial imaging (PPV 76% and 97%, for BCVI Grades II and IV, respectively) compared with Grade I injuries (PPV 30%, p < 0.001). CONCLUSIONS In the current series, multidetector CTA as a screening test for blunt cerebrovascular injury had a high-false positive rate, especially in patients with Grade I BCVI. Given a false-positive rate of 47.9% with an estimated average of 132 patients per year screening positive for BCVI with CTA, approximately 63 patients per year would potentially be treated unnecessarily with antithrombotic therapy at a busy United States Level I trauma center. The authors' data support the use of DSA after positive findings on CTA in patients with suspected BCVI. DSA as an adjunctive test in patients with positive CTA findings allows for increased diagnostic accuracy in correctly diagnosing BCVI while minimizing risk from unnecessary antithrombotic therapy in polytrauma patients.

Resource Utilization After Snakebite Severity Score Implementation into Treatment Algorithm of Crotaline Bite.

BACKGROUND: Crotaline envenomation clinical manifestations vary considerably among patients. Current recommendations for treatment with Crotalidae polyvalent immune Fab require assessment of envenomation control. Determining control of envenomation, particularly when patients are evaluated by different providers in separate clinical settings, can be difficult. OBJECTIVE: To determine if a difference in total vials of Crotalidae antivenin therapy exists between pre-protocol and post-Snakebite Severity Score (SSS) protocol. METHODS: Retrospective medical record review at an academic medical and regional Level I trauma center. Resource utilization in patients with a diagnosis of "snakebite" was compared between patients treated pre- and post-SSS protocol implementation. RESULTS: One hundred forty-six patients were included in the evaluation. One hundred twenty-seven (87.0%) patients received antivenin, n = 80 (90.9%) in the pre-protocol group and n = 47 (81.0%) in the post-protocol group. Median total number of antivenin vials per patient was lower in the post-protocol group than the pre-protocol group, 16 (10-24 interquartile range) vs. 12 (10-16 interquartile range), p = 0.006. This decreased utilization correlates to an approximate $13,200 savings per patient. Hospital and intensive care unit length of stay, opioid use, incidence of blood product transfusion, need for surgical intervention, or need for intubation were not different between groups. CONCLUSIONS: A snakebite protocol with SSS utilization to guide antivenin administration results in significantly decreased antivenin therapy in snakebite patients without increase in other health care utilization.

Evaluating trauma team performance in a Level I trauma center: Validation of the trauma team communication assessment (TTCA-24).

BACKGROUND: Nontechnical skills (NTS), such as team communication, are well-recognized determinants of trauma team performance and good patient care. Measuring these competencies during trauma resuscitations is essential, yet few valid and reliable tools are available. We aimed to demonstrate that the Trauma Team Communication Assessment (TTCA-24) is a valid and reliable instrument that measures communication effectiveness during activations. METHODS: Two tools with adequate psychometric strength (Trauma Nontechnical Skills Scale [T-NOTECHS], Team Emergency Assessment Measure [TEAM]) were identified during a systematic review of medical literature and compared with TTCA-24. Three coders used each tool to evaluate 35 stable and 35 unstable patient activations (defined according to Advanced Trauma Life Support criteria). Interrater reliability was calculated between coders using the intraclass correlation coefficient. Spearman rank correlation coefficient was used to establish concurrent validity between TTCA-24 and the other two validated tools. RESULTS: Coders achieved an intraclass correlation coefficient of 0.87 for stable patient activations and 0.78 for unstable activations scoring excellent on the interrater agreement guidelines. The median score for each assessment showed good team communication for all 70 videos (TEAM, 39.8 of 54; T-NOTECHS, 17.4 of 25; and TTCA-24, 87.4 of 96). A significant correlation between TTTC-24 and T-NOTECHS was revealed (p = 0.029), but no significant correlation between TTCA-24 and TEAM (p = 0.77). Team communication was rated slightly better across all assessments for stable versus unstable patient activations, but not statistically significant. CONCLUSION: TTCA-24 correlated with T-NOTECHS, an instrument measuring nontechnical skills for trauma teams, but not TEAM, a tool that assesses communication in generic emergency settings. TTCA-24 is a reliable and valid assessment that can be a useful adjunct when evaluating interpersonal and team communication during trauma activations. LEVEL OF EVIDENCE: Diagnostic tests or criteria, level II.

Organ Donation, an Unexpected Benefit of Aggressive Resuscitation of Trauma Patients Presenting Dead on Arrival.

BACKGROUND: We sought to determine whether aggressive resuscitation in trauma patients presenting without vital signs, or "dead on arrival," was futile. We also sought to determine whether organ donation was an unexpected benefit of aggressive resuscitation. STUDY DESIGN: We conducted a review of adults presenting to our Level I trauma center with no signs of life (pulse = 0 beats/min; systolic blood pressure = 0 mmHg; and no evidence of neurologic activity, Glasgow Coma Scale score = 3). Primary end point was survival to hospital discharge or major organ donation (ie heart, lung, kidney, liver, or pancreas were harvested). We compared our survival rates with those of the National Trauma Data Bank in 2012. Patient demographics, emergency department vital signs, and outcomes were analyzed. RESULTS: Three hundred and forty patients presented with no signs of life to our emergency department after injury (median Injury Severity Score = 40). There were 7 survivors to discharge, but only 5 (1.5%) were functionally independent (4 were victims of penetrating trauma). Of the 333 nonsurvivors, 12 patients (3.6%) donated major organs (16 kidneys, 2 hearts, 4 livers, and 2 lungs). An analysis of the National Trauma Data Bank yielded a comparable survival rate for those presenting dead on arrival, with an overall survival rate of 1.8% (100 of 5,384); 2.3% for blunt trauma and 1.4% for penetrating trauma. CONCLUSIONS: Trauma patients presenting dead on arrival rarely (1.5%) achieve functional independence. However, organ donation appears to be an under-recognized outcomes benefit (3.6%) of the resuscitation of injury victims arriving without vital signs.

Small Bowel Perforations by Metallic Grill Brush Bristles: Clinical Presentations and Opportunity for Prevention.

Increasing reports on the incidental ingestion of metallic bristles from barbeque grill cleaning brushes have been reported. We sought to describe the clinical presentation and grilling habits of patients presenting after ingesting metallic bristles in an attempt to identify risk factors. We performed a chart review of six patients with documented enteric injury from metallic bristles. Subjects were contacted and administered a survey focused on the events surrounding the bristle ingestion. We arranged for in-home visits to inspect the grill and grill brush whenever possible. Of the six subjects identified, three (50%) were male, five (83%) were white, and they ranged in age from 18 to 65 years (mean 42.5). All complained of abdominal pain. All bristles were identified by CT scan. Three patients underwent laparoscopic enterorrhaphy, and two underwent laparotomy. The remaining patients did not require intervention. None had replaced their grill brush in at least two years. Surgeon's awareness of this unusual injury is important to identify and manage this problem. Alternative methods to clean the grill should be sought and grill brushes should be replaced at least every two years.

"Blush at first sight": significance of computed tomographic and angiographic discrepancy in patients with blunt abdominal trauma.

BACKGROUND: "Blush," defined as a focal area of contrast pooling within a hematoma, is frequently encountered in patients with severe blunt torso trauma. Contemporary clinical practice guidelines recommend the use of angiography with embolization in all hemodynamically stable patients with evidence of active extravasation. Patients presenting with blush visualized on computed tomography (CT), but not demonstrated on subsequent angiography, present a challenging clinical dilemma. The purpose of this study was to study the natural course of patients with this blush disparity between CT and angiography. METHODS: The study was conducted as a retrospective analysis of patients who underwent angiography after initial CT scans revealed blush after blunt abdominal trauma at a level I trauma center (January 2005 to December 2014). RESULTS: A total of 143 patients with blunt splenic injuries were found to have CT blush and underwent catheter angiography. Of the 143 patients with blush on CT, 24 (17%) showed no evidence of blush on angiography. Patients with CT-angiographic discrepancy were more than twice as likely to rebleed compared with those with angiographic evidence of blush (25% vs 10%, P < .05). This is due to the fact that although all patients with blush on angiography underwent embolization, only 7/22 of those with no evidence of blush were embolized. Sixty-eight patients with blunt liver injuries demonstrated blush on CT and underwent catheter angiography. Of the 68 patients with blush on CT, 22 patients (33%) showed no evidence of blush on angiography. None of these 22 patients underwent angioembolization. The rebleeding rate in this cohort was 32% (7/22). Again, this was more than twice the rate observed in patients who did have angiographic evidence of blush and were embolized (11%, 5/46). CONCLUSIONS: CT imaging has enhanced our ability to detect contrast extravasation after injury, and evidence of blush on CT suggests the presence of active hemorrhage. This analysis suggests that in clinical situations in which CT blush is noted secondary to blunt trauma to the spleen or liver, a negative angiogram still carries a significant risk of recurrent hemorrhage; consideration for empiric embolization at the time of the initial procedure even in the absence of blush on angiographic evaluation is thus warranted. Prospective studies are needed to validate these findings and to assess the utility of this clinical paradigm.

The splenic injury outcomes trial: An American Association for the Surgery of Trauma multi-institutional study.

BACKGROUND: Delayed splenic hemorrhage after nonoperative management (NOM) of blunt splenic injury (BSI) is a feared complication, particularly in the outpatient setting. Significant resources, including angiography (ANGIO), are used in an effort to prevent delayed splenectomy (DS). No prospective, long-term data exist to determine the actual risk of splenectomy. The purposes of this trial were to ascertain the 180-day risk of splenectomy after 24 hours of NOM of BSI and to determine factors related to splenectomy. METHODS: Eleven Level I trauma centers participated in this prospective observational study. Adult patients achieving 24 hours of NOM of their BSI were eligible. Patients were followed up for 180 days. Demographic, physiologic, radiographic, injury-related information, and spleen-related interventions were recorded. Bivariate and multivariable analyses were used to determine factors associated with DS. RESULTS: A total of 383 patients were enrolled. Twelve patients (3.1%) underwent in-hospital splenectomy between 24 hours and 9 days after injury. Of 366 discharged with a spleen, 1 (0.27%) required readmission for DS on postinjury Day 12. No Grade I injuries experienced DS. The splenectomy rate after 24 hours of NOM was 1.5 per 1,000 patient-days. Only extravasation from the spleen at time of admission (ADMIT-BLUSH) was associated with splenectomy (odds ratio, 3.6; 95% confidence interval, 1.4-12.4). Of patients with ADMIT-BLUSH (n = 49), 17 (34.7%) did not have ANGIO with embolization (EMBO), and 2 of those (11.8%) underwent splenectomy; 32 (65.3%) underwent ANGIO with EMBO, and 2 of those (6.3%, p = 0.6020 compared with no ANGIO with EMBO) required splenectomy. CONCLUSION: Splenectomy after 24 hours of NOM is rare. After the initial 24 hours, no additional interventions are warranted for patients with Grade I injuries. For Grades II to V, close observation as an inpatient or outpatient is indicated for 10 days to 14 days. ADMIT-BLUSH is a strong predictor of DS and should lead to close observation or earlier surgical intervention. LEVEL OF EVIDENCE: Prognostic/epidemiological study, level III; therapeutic study, level IV.

Statistical Machines for Trauma Hospital Outcomes Research: Application to the PRospective, Observational, Multi-Center Major Trauma Transfusion (PROMMTT) Study.

Improving the treatment of trauma, a leading cause of death worldwide, is of great clinical and public health interest. This analysis introduces flexible statistical methods for estimating center-level effects on individual outcomes in the context of highly variable patient populations, such as those of the PRospective, Observational, Multi-center Major Trauma Transfusion study. Ten US level I trauma centers enrolled a total of 1,245 trauma patients who survived at least 30 minutes after admission and received at least one unit of red blood cells. Outcomes included death, multiple organ failure, substantial bleeding, and transfusion of blood products. The centers involved were classified as either large or small-volume based on the number of massive transfusion patients enrolled during the study period. We focused on estimation of parameters inspired by causal inference, specifically estimated impacts on patient outcomes related to the volume of the trauma hospital that treated them. We defined this association as the change in mean outcomes of interest that would be observed if, contrary to fact, subjects from large-volume sites were treated at small-volume sites (the effect of treatment among the treated). We estimated this parameter using three different methods, some of which use data-adaptive machine learning tools to derive the outcome models, minimizing residual confounding by reducing model misspecification. Differences between unadjusted and adjusted estimators sometimes differed dramatically, demonstrating the need to account for differences in patient characteristics in clinic comparisons. In addition, the estimators based on robust adjustment methods showed potential impacts of hospital volume. For instance, we estimated a survival benefit for patients who were treated at large-volume sites, which was not apparent in simpler, unadjusted comparisons. By removing arbitrary modeling decisions from the estimation process and concentrating on parameters that have more direct policy implications, these potentially automated approaches allow methodological standardization across similar comparativeness effectiveness studies.

Clinical gestalt and the prediction of massive transfusion after trauma.

INTRODUCTION: Early recognition and treatment of trauma patients requiring massive transfusion (MT) has been shown to reduce mortality. While many risk factors predicting MT have been demonstrated, there is no universally accepted method or algorithm to identify these patients. We hypothesised that even among experienced trauma surgeons, the clinical gestalt of identifying patients who will require MT is unreliable. METHODS: Transfusion and mortality outcomes after trauma were observed at 10 U.S. Level-1 trauma centres in patients who survived ≥ 30 min after admission and received ≥ 1 unit of RBC within 6h of arrival. Subjects who received ≥ 10 units within 24h of admission were classified as MT patients. Trauma surgeons were asked the clinical gestalt question "Is the patient likely to be massively transfused?" 10 min after the patients arrival. The performance of clinical gestalt to predict MT was assessed using chi-square tests and ROC analysis to compare gestalt to previously described scoring systems. RESULTS: Of the 1245 patients enrolled, 966 met inclusion criteria and 221 (23%) patients received MT. 415 (43%) were predicted to have a MT and 551(57%) were predicted to not have MT. Patients predicted to have MT were younger, more often sustained penetrating trauma, had higher ISS scores, higher heart rates, and lower systolic blood pressures (all p<0.05). Gestalt sensitivity was 65.6% and specificity was 63.8%. PPV and NPV were 34.9% and 86.2% respectively. CONCLUSION: Data from this large multicenter trial demonstrates that predicting the need for MT continues to be a challenge. Because of the increased mortality associated with delayed therapy, a more reliable algorithm is needed to identify and treat these severely injured patients earlier.

Natural history and clinical implications of nondepressed skull fracture in young children.

BACKGROUND: Head injury is the most common cause of neurologic disability and mortality in children. Previous studies have demonstrated that depressed skull fractures (SFs) represent approximately one quarter of all SFs in children and approximately 10% percent of hospital admissions after head injury. We hypothesized that nondepressed SFs (NDSFs) in children are not associated with adverse neurologic outcomes. METHODS: Medical records were reviewed for all children 5 years or younger with SFs who presented to our Level I trauma center during a 4-year period. Data collected included patient demographics, Glasgow Coma Scale (GCS) score at admission, level of consciousness at the time of injury, type of SF (depressed SF vs. NDSF), magnitude of the SF depression, evidence of neurologic deficit, and the requirement for neurosurgical intervention. RESULTS: We evaluated 1,546 injured young children during the study period. From this cohort, 563 had isolated head injury, and 223 of them had SF. Of the SF group, 163 (73%) had NDSFs, of whom 128 (78%) presented with a GCS score of 15. None of the NDSF patients with a GCS score of 15 required neurosurgical intervention or developed any neurologic deficit. Of the remaining 35 patients with NDSF and GCS score less than 15, 7 (20%) had a temporary neurologic deficit that resolved before discharge, 4 (11%) developed a persistent neurologic deficit, and 2 died (6%). CONCLUSION: Children 5 years or younger with NDSFs and a normal neurologic examination result at admission do not develop neurologic deterioration. LEVEL OF EVIDENCE: Epidemiological study, level III.

Early resuscitation intensity as a surrogate for bleeding severity and early mortality in the PROMMTT study.

BACKGROUND: The classic definition of massive transfusion, 10 or more units of red blood cells (RBCs) in 24 hours, has never been demonstrated as a valid surrogate for severe hemorrhage and can introduce survival bias. In addition, the definition fails to capture other products that the clinician may have immediately available, and may use, during the initial resuscitation. Assuming that units of resuscitative fluids reflect patient illness, our objective was to identify a rate of resuscitation intensity (RI) that could serve as an early surrogate of sickness for patients with substantial bleeding after injury. METHODS: Adult patients surviving at least 30 minutes after admission and receiving one or more RBCs within 6 hours of admission from 10 US Level 1 trauma centers were enrolled in the PRospective Observational Multicenter Major Trauma Transfusion (PROMMTT) study. Total fluid units were calculated as the sum of the number of crystalloid units (1 L = 1 U), colloids (0.5 L = 1 U), and blood products (1 RBC = 1 U, 1 plasma = 1 U, 6 pack platelets = 1 U). Univariable and multivariable logistic regressions were used to evaluate associations between RI and 6-hour mortality, adjusting for age, center, penetrating injury, weighted Revised Trauma Score (RTS), and Injury Severity Score (ISS). RESULTS: A total of 1,096 eligible patients received resuscitative fluids within 30 minutes, including 620 transfused with blood products. Despite varying products used, the total fluid RI was similar across all sites (3.2 ± 2.5 U). Patients who received four or more units of any resuscitative fluid had a 6-hour mortality rate of 14.4% versus 4.5% in patients who received less than 4 U. The adjusted odds ratio of 6-hour mortality for patients receiving 4 U or more within 30 minutes was 2.1 (95% confidence interval, 1.2-3.5). CONCLUSION: Resuscitation with four or more units of any fluid was significantly associated with 6-hour mortality. This study suggests that early RI regardless of fluid type can be used as a surrogate for sickness and mortality in severely bleeding patients.

Resuscitate early with plasma and platelets or balance blood products gradually: findings from the PROMMTT study.

BACKGROUND: The trauma transfusion literature has yet to resolve which is more important for hemorrhaging patients, transfusing plasma and platelets along with red blood cells (RBCs) early in resuscitation or gradually balancing blood product ratios. In a previous report of PROMMTT results, we found (1) plasma and platelet:RBC ratios increased gradually during the 6 hours following admission, and (2) patients achieving ratios more than 1:2 (relative to ratios <1:2) had significantly decreased 6-hour to 24-hour mortality adjusting for baseline and time-varying covariates. To differentiate the association of in-hospital mortality with early plasma or platelet transfusion from that with delayed but gradually balanced ratios, we developed a separate analytic approach. METHODS: Using PROMMTT data and multilevel logistic regression to adjust for center effects, we related in-hospital mortality to the early receipt of plasma or platelets within the first three to six transfusion units (including RBCs) and 2.5 hours of admission. We adjusted for the same covariates as in our previous report: Injury Severity Score (ISS), age, time and total number of blood product transfusions upon entry to the analysis cohort, and bleeding from the head, chest, or limb. RESULTS: Of 1,245 PROMMTT patients, 619 were eligible for this analysis. Early plasma was associated with decreased 24-hour and 30-day mortality (adjusted odds ratios of 0.47 [p = 0.009] and 0.44 [p = 0.002], respectively). Too few patients (24) received platelets early for meaningful assessment. In the subgroup of 222 patients receiving no early plasma but continuing transfusions beyond Hour 2.5, achieving gradually balanced plasma and platelet:RBC ratios of 1:2 or greater by Hour 4 was not associated with 30-day mortality (adjusted odds ratios of 0.9 and 1.1, respectively). There were no significant center effects. CONCLUSION: Plasma transfusion early in resuscitation had a protective association with mortality, whereas delayed but gradually balanced transfusion ratios did not. Further research will require considerably larger numbers of patients receiving platelets early.

Waiver of consent in noninterventional, observational emergency research: the PROMMTT experience.

BACKGROUND: In the PRospective Observational Multicenter Major Trauma Transfusion (PROMMTT) study, waiver of consent was used because previous literature reported low response rates and subsequent bias. The goal of this article was to examine the rationale and tradeoffs of using waiver of consent in PROMMTT. METHODS: PROMMTT enrolled trauma patients receiving at least 1 U of red blood cells within 6 hours after admission at 10 US Level 1 trauma centers. Local institutional review boards (IRBs) from all sites approved the study. Site 8 was required by their IRB to attempt consent but was allowed to retain data on patients unable to be consented. RESULTS: Of 121 subjects enrolled at Site 8, 55 consents were obtained (46%), and no patient or legally authorized representative refused to give consent. Of the patients, 36 (30%) died, and 6 (5%) were discharged before consent could be attempted. Consent was attempted but not possible among 24 patients (20%). Of the 10 clinical sites, 6 of the local IRBs approved collection of residual blood samples, 1 had previous approval to collect timed blood samples under a separate protocol, and 3 reported that their local IRBs would not approve collection of residual blood under a waiver of consent. CONCLUSION: Waiver of consent was used in PROMMTT because of the potential adverse impact of consent refusals; however, there were no refusals. If the IRB for Site 8 had required withdrawal of patients unable to consent and destruction of their data, a serious bias would likely have been introduced. Other tradeoffs included a reduction in sites participating in residual blood collection and a smaller than expected amount of residual blood collected among sites operating under a waiver of consent. Noninterventional emergency research studies should consider these potential tradeoffs carefully before deciding whether waiver of consent would best achieve the goals of a study.

Cryoprecipitate use in the PROMMTT study.

BACKGROUND: There are few clinical data to guide the use of cryoprecipitate in severely injured trauma patients. Cryoprecipitate is a rich source of fibrinogen and has been associated with improved survival in animal as well as limited human studies. Our objectives were to identify patterns and predictors of cryoprecipitate use and determine whether transfusing cryoprecipitate was associated with improved survival. METHODS: This secondary analysis of 1,238 of 1,245 PRospective Observational Multicenter Major Trauma Transfusion (PROMMTT) study patients who had timed transfusion data included 359 (29%) who received cryoprecipitate. For this analysis, one dose of cryoprecipitate was defined as 10 U. Unadjusted predictors of cryoprecipitate use were identified using logistic regression. Multivariable time-dependent Cox models were performed to examine the association of cryoprecipitate on time to in-hospital death. RESULTS: Cryoprecipitate use varied significantly by center, ranging from 7% to 82%. Among patients who received cryoprecipitate, the median number of units infused by 24 hours was 10 (interquartile range, 10-20). The median time from admission to first cryoprecipitate unit was 2.7 hours (interquartile range, 1.7-4.4 hours). Of those who died of a hemorrhagic death within 6 hours of admission, 72% received no cryoprecipitate. Other unadjusted predictors of cryoprecipitate use included Injury Severity Score (ISS), initial fibrinogen levels, base deficit, international normalized ratio, prothrombin time/partial thromboplastin time, hemoglobin, damage-control surgery, and surgical intervention of the chest and abdomen. Cryoprecipitate use was not associated with in-hospital mortality after adjusting for initial pH, initial hemoglobin, emergency department systolic blood pressure, emergency department Glasgow Coma Scale (GCS) score, blood product use, ISS, and center. CONCLUSION: Ten US Level 1 trauma centers vary greatly in their timing and use of cryoprecipitate in severely injured trauma patients. We could not identify any association of cryoprecipitate use with in-hospital mortality, although most patients did not receive this product. Randomized controlled studies are needed to determine if cryoprecipitate (or fibrinogen concentrates) have a beneficial effect.

Clinical and mechanistic drivers of acute traumatic coagulopathy.

BACKGROUND: Acute traumatic coagulopathy (ATC) occurs after severe injury and shock and is associated with increased bleeding, morbidity, and mortality. The effects of ATC and hemostatic resuscitation on outcome are not well-explored. The PRospective Observational Multicenter Major Trauma Transfusion (PROMMTT) study provided a unique opportunity to characterize coagulation and the effects of resuscitation on ATC after severe trauma. METHODS: Blood samples were collected upon arrival on a subset of PROMMTT patients. Plasma clotting factor levels were prospectively assayed for coagulation factors. These data were analyzed with comprehensive PROMMTT clinical data. RESULTS: There were 1,198 patients with laboratory results, of whom 41.6% were coagulopathic. Using international normalized ratio of 1.3 or greater, 41.6% of patients (448) were coagulopathic, while 20.5% (214) were coagulopathic using partial thromboplastin time of 35 or greater. Coagulopathy was primarily associated with a combination of an Injury Severity Score (ISS) of greater than 15 and a base deficit (BD) of less than -6 (p < 0.05). Regression modeling for international normalized ratio-based coagulopathy shows that prehospital crystalloid (odds ratio [OR], 1.05), ISS (OR, 1.03), Glasgow Coma Scale (GCS) score (OR, 0.93), heart rate (OR, 1.08), systolic blood pressure (OR, 0.96), BD (OR, 0.92), and temperature (OR, 0.84) were significant predictors of coagulopathy (all p < 0.03). A subset of 165 patients had blood samples collected and coagulation factor analysis performed. Elevated ISS and BD were associated with elevation of aPC and depletion of factors (all p < 0.05). Reductions in factors I, II, V, VIII and an increase in aPC drive ATC (all p < 0.04). Similar results were found for partial thromboplastin time-defined coagulopathy. CONCLUSION: ATC is associated with the depletion of factors I, II, V, VII, VIII, IX, and X and is driven by the activation of the protein C system. These data provide additional mechanistic understanding of the drivers of coagulation abnormalities after injury. Further understanding of the drivers of ATC and the effects of resuscitation can guide factor-guided resuscitation and correction of coagulopathy after injury.

Increasing time to operation is associated with decreased survival in patients with a positive FAST examination requiring emergent laparotomy.

INTRODUCTION: Focused assessment with sonography for trauma (FAST) is commonly used to facilitate the timely diagnosis of life-threatening hemorrhage in injured patients. Most patients with positive findings on FAST require laparotomy. Although it is assumed that an increasing time to operation (T-OR) leads to higher mortality, this relationship has not been quantified. This study sought to determine the impact of T-OR on survival in patients with a positive FAST who required emergent laparotomy. METHODS: We retrospectively analyzed patients from the PRospective Observational Multicenter Major Trauma Transfusion (PROMMTT) study who underwent laparotomy within 90 minutes of presentation and had a FAST performed. Cox proportional hazards models including Injury Severity Score (ISS), age, base deficit, and hospital site were created to examine the impact of increasing T-OR on in-hospital survival at 24 hours and 30 days. The impact of time from the performance of the FAST examination to operation (TFAST-OR) on in-hospital mortality was also examined using the same model. RESULTS: One hundred fifteen patients met study criteria and had complete data. Increasing T-OR was associated with increased in-hospital mortality at 24 hours (hazard ratio [HR], 1.50 for each 10-minute increase in T-OR; confidence interval [CI], 1.14-1.97; p = 0.003) and 30 days (HR, 1.41; CI, 1.18-2.10; p = 0.002). Increasing TFAST-OR was also associated with higher in-hospital mortality at 24 hours (HR, 1.34; CI, 1.03-1.72; p = 0.03) and 30 days (HR, 1.40; CI, 1.06-1.84; p = 0.02). CONCLUSION: In patients with a positive FAST who required emergent laparotomy, delay in operation was associated with increased early and late in-hospital mortality. Delays in T-OR in trauma patients with a positive FAST should be minimized.

Application of the Berlin definition in PROMMTT patients: the impact of resuscitation on the incidence of hypoxemia.

BACKGROUND: Acute lung injury following trauma resuscitation remains a concern despite recent advances. With the use of the PROMMTT study population, the risk of hypoxemia and potential modifiable risk factors are studied. METHODS: Patients with survival for 24 hours or greater with at least one intensive care unit day were included in the analysis. Hypoxemia was categorized using the Berlin definition for adult respiratory distress syndrome: none (PaO2-to-FIO2 ratio [P/F] > 300 mm Hg), mild (P/F, 201-300 mm Hg), moderate (P/F, 101-200 mm Hg) or severe (P/F ≤ 100 mm Hg). The cohort was dichotomized into those with none or mild hypoxemia and those with moderate or severe injury. Early resuscitation was defined as that occurring 0 hour to 6 hours from arrival; late resuscitation was defined as that occurring 7 hours to 24 hours. Multivariate logistic regression models were developed controlling for age, sex, mechanisms of injury, arrival physiology, individual Abbreviated Injury Scale (AIS) scores, blood transfusions, and crystalloid administration. RESULTS: Of the patients 58.7% (731 of 1,245) met inclusion criteria. Hypoxemia occurred in 69% (mild, 24%; moderate, 28%; severe, 17%). Mortality was highest (24%) in the severe group. During early resuscitation (0-6 h), logistic regression revealed age (odd ratio [OR], 1.02; 95% confidence interval [CI], 1.00-1.04), chest AIS score (OR, 1.31; 95% CI, 1.10-1.57), and intravenously administered crystalloid fluids given in 500 mL increments (OR, 1.12; 95% CI, 1.01-1.25) as predictive of moderate or severe hypoxemia. During late resuscitation, age (OR, 1.02; 95% CI, 1.00-1.04), chest AIS score (OR, 1.33; 95% CI, 1.11-1.59), and crystalloids given during this period (OR, 1.05; 95% CI, 1.01-1.10) were also predictive of moderate-to-severe hypoxemia. Red blood cell, plasma, and platelet transfusions (whether received during early or late resuscitation) failed to demonstrate an increased risk of developing moderate/severe hypoxemia. CONCLUSION: Severe chest injury, increasing age, and crystalloid-based resuscitation, but not blood transfusions, were associated with increased risk of developing moderate-to-severe hypoxemia following injury.