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Fresh whole blood from walking blood banks for patients with traumatic hemorrhagic shock: a systematic review and meta-analysis
Naumann DN, Boulton AJ, Sandhu A, Campbell K, Charlton W, Gurney JM, Martin MJ, Scorer T, Doughty H
The Journal of Trauma and Acute Care Surgery. 2020
Abstract
BACKGROUND Whole blood (WB) is optimal for resuscitation of traumatic haemorrhage. Walking Blood Banks (WBB) provide fresh whole blood (FWB) where conventional blood components or stored, tested WB are not readily available. There is an increasing interest in this as an emergency resilience measure for isolated communities and during crises including the COVID-19 pandemic. We conducted a systematic review and meta-analysis of the available evidence to inform practice. METHODS Standard systematic review methodology was used to obtain studies that reported the delivery of FWB (PROSPERO registry CRD42019153849). Studies that only reported WB from conventional blood banking were excluded. For outcomes, odds ratios (OR) and 95% confidence interval (CI) were calculated using random effects modelling due to high risk of heterogeneity. Quality of evidence was assessed using the GRADE system. RESULTS 27 studies published from 2006 - 2020 reported >10,000 units of FWB for >3000 patients (precise values not available for all studies). Evidence for studies was "low" or "very low" except for one study which was "moderate" in quality. FWB patients were more severely injured than non-FWB patients. Overall, survival was equivalent between FWB and non-FWB groups for 8 studies that compared these (OR 1.00 (95% CI 0.65, 1.55); p=0.61). However, the highest quality study (matched groups for physiological and injury characteristics) reported an adjusted OR of 0.27 (95% CI 0.13-0.58) for mortality for the FWB group; p<0.01. CONCLUSIONS Thousands of units of FWB from WBBs have been transfused in patients following life-threatening haemorrhage. Survival is equivalent for FWB resuscitation when compared to non-FWB, even when patients were more severely injured. Evidence is scarce and of relative low quality and may underestimate potential adverse events. Whereas WBB may be an attractive resilience measure, caution is still advised. WBBs should be subject to prospective evaluation to optimise care and inform policy. LEVEL OF EVIDENCE Therapeutic, level 3.