Mechanism of Injury May Influence Infection Risk from Early Blood Transfusion.

BACKGROUND: Blood transfusion is a known risk factor for infection in trauma patients. Differences based on mechanism of injury have not been well described. We hypothesize that infection risk in trauma patients with early blood transfusion is different based on blunt or penetrating mechanism of injury. PATIENTS AND METHODS: Adults admitted to the trauma intensive care unit from January 2010 through January 2015 were reviewed retrospectively. Those receiving transfusion after 24 h were excluded. Infections were defined as positive bronchoalveolar lavage, blood, urine, wound, or abdominal cultures. Logistic regression identified independent predictors of infection. Significance was considered at p ≤ 0.05. RESULTS: With blunt trauma (n = 625), the transfusion rate was 36% (n = 223), with 30% (n = 186) infections. Those with an infection were more severely injured, had a higher operation rate, lower Glasgow Coma Score (GCS), longer hospital stay, and higher transfusion rate (all p < 0.001). With penetrating trauma (n = 292), the transfusion rate was 54% (n = 159), with 26% (n = 77) infections. Those with an infection were older, more severely injured, had a higher operation rate, lower GCS, longer length of stay, and higher transfusion rate (all p < 0.01). Controlling for age, injury severity score (ISS), revised trauma score (RTS), GCS, and hospital stay, transfusion was an independent predictor of infection in patients with blunt (odds ratio: 2.1, 95% confidence intervals: 1.272-3.393, p = 0.003) but not penetrating trauma. CONCLUSIONS: Early blood transfusion increases infection risk in blunt but not penetrating trauma.

Association of Mechanism of Injury With Risk for Venous Thromboembolism After Trauma.

Importance: To date, no study has assessed whether the risk of venous thromboembolism (VTE) varies with blunt or penetrating trauma. Objective: To test whether the mechanism of injury alters risk of VTE after trauma. Design, Setting, and Participants: A retrospective database review was conducted of adults admitted to the intensive care unit of an American College of Surgeons-verified level I trauma center between August 1, 2011, and January 1, 2015, with blunt or penetrating injuries. Univariate and multivariable analyses identified independent predictors of VTE. Main Outcomes and Measures: Differences in risk factors for VTE with blunt vs penetrating trauma. Results: In 813 patients with blunt trauma (mean [SD] age, 47 [19] years) and 324 patients with penetrating trauma (mean [SD] age, 35 [15] years), the rate of VTE was 9.1% overall (104 of 1137) and similar between groups (blunt trauma, 9% [n = 73] vs penetrating trauma, 9.6% [n = 31]; P = .76). In the blunt trauma group, more patients with VTE than without VTE had abnormal coagulation results (49.3% vs 35.7%; P = .02), femoral catheters (9.6% vs 3.9%; P = .03), repair and/or ligation of vascular injury (15.1% vs 5.4%; P = .001), complex leg fractures (34.2% vs 18.5%; P = .001), Glasgow Coma Scale score less than 8 (31.5% vs 10.7%; P < .001), 4 or more transfusions (51.4% vs 17.6%; P < .001), operation time longer than 2 hours (35.6% vs 16.4%; P < .001), and pelvic fractures (43.8% vs 21.4%; P < .001); patients with VTE also had higher mean (SD) Greenfield Risk Assessment Profile scores (13 [6] vs 8 [4]; P ≤ .001). However, with multivariable analysis, only receiving 4 or more transfusions (odds ratio [OR], 3.47; 95% CI, 2.04-5.91), Glasgow Coma Scale score less than 8 (OR, 2.75; 95% CI, 1.53-4.94), and pelvic fracture (OR, 2.09; 95% CI, 1.23-3.55) predicted VTE, with an area under the receiver operator curve of 0.730. In the penetrating trauma group, more patients with VTE than without VTE had abnormal coagulation results (64.5% vs 44.4%; P = .03), femoral catheters (16.1% vs 5.5%; P = .02), repair and/or ligation of vascular injury (54.8% vs 25.3%; P < .001), 4 or more transfusions (74.2% vs 39.6%; P < .001), operation time longer than 2 hours (74.2% vs 50.5%; P = .01), Abbreviated Injury Score for the abdomen greater than 2 (64.5% vs 42.3%; P = .02), and were aged 40 to 59 years (41.9% vs 23.2%; P = .02); patients with VTE also had higher mean (SD) Greenfield Risk Assessment Profile scores (12 [4] vs 7 [4]; P < .001). However, with multivariable analysis, only repair and/or ligation of vascular injury (OR, 3.32; 95% CI, 1.37-8.03), Abbreviated Injury Score for the abdomen greater than 2 (OR, 2.77; 95% CI, 1.19-6.45), and age 40 to 59 years (OR, 2.69; 95% CI, 1.19-6.08) predicted VTE, with an area under the receiver operator curve of 0.760. Conclusions and Relevance: Although rates of VTE are the same in patients who experienced blunt and penetrating trauma, the independent risk factors for VTE are different based on mechanism of injury. This finding should be a consideration when contemplating prophylactic treatment protocols.

Is Hydroxyethyl Starch Safe in Penetrating Trauma Patients?

OBJECTIVES: For logistic reasons, a bolus of 6% hydroxyethyl starch (HES 450/0.7 in lactated electrolyte injection) is recommended for battlefield resuscitation even though it has risks of mortality and acute kidney injury (AKI) in certain patient populations. The purpose of this study was to test the hypothesis that victims of penetrating trauma have no increased risks of AKI and/or death when receiving a single bolus of HES during initial fluid resuscitation. METHODS: 816 consecutive admissions with penetrating trauma were reviewed. Patients who died within 24 hours were excluded. Propensity scores and a 1:1 fixed ratio nearest neighbor matching were used to compare those who received HES to those who did not. Data were expressed as mean ± SD and significance was assessed at p < 0.05. RESULTS: The cohort was 88% male, age 35 ± 14 years, injury severity score of 10 ± 10, with a 3.8% rate of AKI, and 3.2% rate of mortality. HES was administered to 121 (14.8%) patients. In HES and no HES propensity matched groups, the rate of AKI was 3.8% vs. 4.8% (p = 0.749) and the 90-day mortality rate was 3.8% vs. 4.8% (p = 0.749). CONCLUSION: An increased risk of mortality or AKI was not observed in penetrating trauma patients who were resuscitated with low volume HES.

Coagulation Profile Changes Due to Thromboprophylaxis and Platelets in Trauma Patients at High-Risk for Venous Thromboembolism.

We hypothesize there are coagulation profile changes associated both with initiation of thromboporphylaxis (TPX) and with change in platelet levels in trauma patients at high-risk for venous thromboembolism (VTE). A total of 1203 trauma intensive care unit patients were screened with a VTE risk assessment profile. In all, 302 high-risk patients (risk assessment profile score ≥ 10) were consented for weekly thromboelastography. TPX was initiated between initial and follow-up thromboelastography. Seventy-four patients were analyzed. Upon admission, 87 per cent were hypercoagulable, and 81 per cent remained hypercoagulable by Day 7 (P = 0.504). TPX was initiated 3.4 ± 1.4 days after admission; 68 per cent received unfractionated heparin and 32 per cent received low-molecular-weight heparin. The VTE rate was 18 per cent, length of stay 38 (25-37) days, and mortality of 17.6 per cent. In all, 76 per cent had a rapid clotting time at admission versus 39 per cent at Day 7 (P < 0.001); correcting from 7.75 (6.45-8.90) minutes to 10.45 (7.90-15.25) minutes (P < 0.001). At admission, 41 per cent had an elevated maximum clot formation (MCF) and 85 per cent had at Day 7 (P < 0.001); increasing from 61(55-65) mm to 75(69-80) mm (P < 0.001). Platelets positively correlated with MCF at admission (r = 0.308, R(2) = 0.095, P = 0.008) and at Day 7 (r = 0.516, R(2) = 0.266, P < 0.001). Change in platelet levels correlated with change in MCF (r = 0.332, R(2) = 0.110, P = 0.005). In conclusion, hypercoagulability persists despite the use of TPX. Although clotting time normalizes, MCF increases in correlation with platelet levels. As platelet function is a dominant contributor to sustained trauma-evoked hypercoagulability, antiplatelet therapy may be indicated in the management of severely injured trauma patients.