Meta-analysis of plasma to red blood cell ratios and mortality in massive blood transfusions for trauma
BACKGROUND The current military paradigm for blood transfusion in major trauma favours high plasma:RBC ratios. This study aimed determine whether high plasma:red blood cell (RBC) ratios during massive transfusion for trauma decrease mortality, using meta-analysis of contemporaneous groups matched for injury severity score. METHODS A systemic review of the published literature for massive blood transfusions in trauma was performed. Patients were categorised into groups based on plasma:RBC transfusion ratios. Meta-analysis was only performed when there were no significant differences in Injury Severity Score (ISS) between ratio groups within studies. The main endpoint was 30-day mortality. RESULTS Six observational studies reporting outcomes for 1885 patients were included in this meta-analysis. Five studies were from civilian environments and one from a military setting. Ratio cut-offs at 1:2 were the most commonly reported, demonstrating a survival advantage with higher ratios (OR 0.49, 95% CI 0.31-0.80, p=0.004). Ratios>=1:2 showed a significant reduction in mortality compared to lower ratios (OR 0.56, 95% CI 0.40-0.78, p<0.001). Reducing the cut-off level was still protective (ratios between 1:2.5 and 1:4, OR 0.41), although the confidence interval was wide (0.16-1.00, p=0.05) and data heterogenous (I(2)=78%). Ratios of 1:1 were not proven to confer additional benefit beyond ratios of 1:2 (OR 0.50, 95% CI 0.37-0.68, p<0.001). CONCLUSIONS In groups matched for ISS, there was a survival benefit with high plasma:RBC resuscitation ratios. No additional benefits of 1:1 over 1:2 ratios were identified. Copyright 2012. Published by Elsevier Ltd.
Intraoperative blood salvage in penetrating abdominal trauma: a randomised, controlled trial
World Journal of Surgery. 2006;30((6):):1074-80.
BACKGROUND Blood is a scarce and costly resource. Transfusion is often required after major trauma but blood may not be readily available, and concerns remain over the potential adverse consequences of allogeneic blood transfusion. Intraoperative blood salvage (IBS) is used extensively after blunt abdominal trauma, but when blood is contaminated by enteric contents its use has been considered contraindicated. METHODS This was a randomised, controlled trial conducted with Ethical Review Board approval in an inner city trauma unit. Patients with penetrating torso injury requiring a laparotomy and who had exhibited hypotension either pre-hospital or on arrival and in whom there was considered to be significant blood loss were randomly assigned to 2 groups. The control group was given allogeneic blood transfusion at the discretion of the attending medical staff. The cell save (CS) group underwent IBS with transfusion of both allogeneic and autologous blood. All patients received prophylactic antibiotics. The primary outcome was exposure to allogeneic blood up to the first 24 hours postinjury. RESULTS Twenty-three patients were entered into the control group and 21 into the CS group. The groups were equivalent in demographic details, injury patterns and injury severity. The mean volume of salvaged blood re-infused in the CS group was 1,493 ml (range 0-2,690 ml). The mean number of units of allogeneic blood transfused in the first 24 hours in the control group was 11. 17 compared to 6. 47 in the CS group (P=0. 008). Enteric injury had been sustained in 17/23 (75%) of the control group and 18/21 (85%) of the CS group (P=NS). Survival in the control group was 8/23 (35%) compared to 7/21 (33. 3%) in the CS arm (P=NS). Patients with documented postoperative sepsis were significantly more likely to die compared to those without sepsis (P=0. 04); however, those patients in the CS arm were no more likely to develop sepsis compared to those who received allogeneic blood alone. CONCLUSION In this randomised, controlled trial for patients with penetrating abdominal injuries, IBS led to a significant reduction in allogeneic blood usage with no discernable effect on rates of postoperative infection or mortality.