ABSTRACT
Objective: Venous thromboembolism (VTE) risk reduction strategies include early initiation of chemoprophylaxis, reducing missed doses, weight-based dosing and dose adjustment using anti-Xa levels. We hypothesized that time to initiation of chemoprophylaxis would be the strongest modifiable risk for VTE, even after adjusting for competing risk factors. Methods: A prospectively maintained trauma registry was queried for patients admitted July 2017-October 2021 who were 18 years and older and received emergency release blood products. Patients with deep vein thrombosis or pulmonary embolism (VTE) were compared to those without (no VTE). Door-to-prophylaxis was defined as time from hospital arrival to first dose of VTE chemoprophylaxis (hours). Univariate and multivariate analyses were then performed between the two groups. Results: 2047 patients met inclusion (106 VTE, 1941 no VTE). There were no differences in baseline or demographic data. VTE patients had higher injury severity score (29 vs 24), more evidence of shock by arrival lactate (4.6 vs 3.9) and received more post-ED transfusions (8 vs 2 units); all p<0.05. While there was no difference in need for enoxaparin dose adjustment or missed doses, door-to-prophylaxis time was longer in the VTE group (35 vs 25 hours; p=0.009). On multivariate logistic regression analysis, every hour delay from time of arrival increased likelihood of VTE by 1.5% (OR 1.015, 95% CI 1.004 to 1.023, p=0.004). Conclusion: The current retrospective study of severely injured patients with trauma who required emergency release blood products found that increased door-to-prophylaxis time was significantly associated with an increased likelihood for VTE. Chemoprophylaxis initiation is one of the few modifiable risk factors available to combat VTE, therefore early initiation is paramount. Similar to door-to-balloon time in treating myocardial infarction and door-to-tPA time in stroke, "door-to-prophylaxis time" should be considered as a hospital metric for prevention of VTE in trauma. Level of evidence: Level III, retrospective study with up to two negative criteria.
ABSTRACT
Objectives: Some centers have recommended including concentrated fibrinogen replacement in massive transfusion protocols (MTPs). Given our center's policy of aggressive early balanced resuscitation (1:1:1), beginning prehospital, we hypothesized that our rates of hypofibrinogenemia may be lower than those previously reported. Methods: In this retrospective cohort study, patients presenting to our trauma center November 2017 to April 2021 were reviewed. Patients were defined as hypofibrinogenemic (HYPOFIB) if admission fibrinogen <150 or rapid thrombelastography angle <60. Univariate and multivariable analyses assessed risk factors for HYPOFIB. Inverse probability of treatment weighting analyses assessed the relationship between cryoprecipitate administration and outcomes. Results: Of 29 782 patients, 6618 level 1 activations, and 1948 patients receiving emergency release blood, <1%, 2%, and 7% were HYPOFIB. HYPOFIB patients were younger, had higher head Abbreviated Injury Scale value, and had worse coagulopathy and shock. HYPOFIB had lower survival (48% vs 82%, p<0.001), shorter time to death (median 28 (7, 50) vs 36 (14, 140) hours, p=0.012), and were more likely to die from head injury (72% vs 51%, p<0.001). Risk factors for HYPOFIB included increased age (OR (95% CI) 0.98 (0.96 to 0.99), p=0.03), head injury severity (OR 1.24 (1.06 to 1.46), p=0.009), lower arrival pH (OR 0.01 (0.001 to 0.20), p=0.002), and elevated prehospital red blood cell to platelet ratio (OR 1.20 (1.02 to 1.41), p=0.03). Among HYPOFIB patients, there was no difference in survival for those that received early cryoprecipitate (within 2 hours; 40 vs 47%; p=0.630). On inverse probability of treatment weighted analysis, early cryoprecipitate did not benefit the full cohort (OR 0.52 (0.43 to 0.65), p<0.001), nor the HYPOFIB subgroup (0.28 (0.20 to 0.39), p<0.001). Conclusions: Low rates of hypofibrinogenemia were found in our center which treats hemorrhage with early, balanced resuscitation. Previously reported higher rates may be partially due to unbalanced resuscitation and/or delay in resuscitation initiation. Routine empiric inclusion of concentrated fibrinogen replacement in MTPs is not supported by the currently available data. Level of evidence: Level III.
ABSTRACT
Objective: Among critically injured patients of various blood groups, we sought to compare survival and complication rates between COVID-19-positive and COVID-19-negative cohorts. Background: SARS-CoV-2 infections have been shown to cause endothelial injury and dysfunctional coagulation. We hypothesized that, among patients with trauma in hemorrhagic shock, COVID-19-positive status would be associated with increased mortality and inpatient complications. As a secondary hypothesis, we suspected group O patients with COVID-19 would experience fewer complications than non-group O patients with COVID-19. Methods: We evaluated all trauma patients admitted 4/2020-7/2020. Patients 16 years or older were included if they presented in hemorrhagic shock and received emergency release blood products. Patients were dichotomized by COVID-19 testing and then divided by blood groups. Results: 3281 patients with trauma were evaluated, and 417 met criteria for analysis. Seven percent (29) of patients were COVID-19 positive; 388 were COVID-19 negative. COVID-19-positive patients experienced higher complication rates than the COVID-19-negative cohort, including acute kidney injury, pneumonia, sepsis, venous thromboembolism, and systemic inflammatory response syndrome. Univariate analysis by blood groups demonstrated that survival for COVID-19-positive group O patients was similar to that of COVID-19-negative patients (79 vs 78%). However, COVID-19-positive non-group O patients had a significantly lower survival (38%). Controlling for age, sex and Injury Severity Score, COVID-19-positive patients had a greater than 70% decreased odds of survival (OR 0.28, 95% CI 0.09 to 0.81; p=0.019). Conclusions: COVID-19 status is associated with increased major complications and 70% decreased odds of survival in this group of patients with trauma. However, among patients with COVID-19, blood group O was associated with twofold increased survival over other blood groups. This survival rate was similar to that of patients without COVID-19.
ABSTRACT
BACKGROUND: Whole blood was historically transfused as a type-specific product. Given recent advocacy for low-titer group O whole blood (LTOWB) as a universal blood product, we examined outcomes after LTOWB transfusion stratified by recipient blood groups. STUDY DESIGN: Adult trauma patients receiving prehospital or in-hospital transfusion of LTOWB (November 2017 to July 2020) at a single trauma center were prospectively evaluated. The patients were divided into blood type groups (O, A, B, and AB). Major complications and survival to 30 days were compared. Univariate analyses among blood groups were followed by purposeful regression modeling, reflecting 6 variables of significance: male sex, White race, injury severity, arrival lactate, arrival systolic blood pressure, and emergency department blood products. RESULTS: Of 1,075 patients receiving any LTOWB, 539 (50.1%) were Group O, 340 (31.6%) were Group A, 150 (14.0%) were Group B, and 46 (4.3%) were Group AB. There were no statistically significant differences in demographics, injury severity, hemolysis panels, prehospital vitals, or resuscitation parameters (all p > 0.05). However, arrival systolic pressure was lower (91 vs 102, p = 0.034) and lactate was worse (5.5 vs 4.1, p = 0.048) in Group B patients compared to other groups. While survival and most major complications did not differ across recipient groups, acute kidney injury (AKI) initially appeared higher for Group B. Stepwise regression did not show a difference in AKI rates. This analysis was repeated in patients receiving only component products. Group B again showed no significantly increased risk of AKI (13%) compared to other groups (O 7%, A 7%, AB 5%; p = 0.091). CONCLUSIONS: LTOWB appears to be a safe product for universal use across all blood groups. Group B recipients arrived with worse physiologic values associated with hemorrhagic shock whether receiving LTOWB or standard component products.
