Whole blood versus component therapy for haemostatic resuscitation of major bleeding: a protocol for a systematic review and meta-analysis

Introduction: There is a renewed interest in the use of whole blood (WB) to manage patients with life-threatening bleeding. We aimed to estimate mortality and complications risk between WB and blood component therapy for haemostatic resuscitation of major bleeding.

Methods: We will conduct a systematic review and meta-analysis of studies published between 1 January 1980 and 1 January 2020, identified from PubMed and Scopus databases. Population will be patients who require blood transfusion (traumatic operative, obstetric and gastrointestinal bleeding). Intervention is WB transfusion such as fresh WB (WB unit stored for less than 48 hours), leukoreduced modified WB (with platelets removed during filtration), warm fresh WB (stored warm at 22°C for up to 8 hours and then for a maximum of an additional 24 hours at 4°C). The primary outcomes will be the 24-hour and 30-day survival rates (in-hospital mortality). Comparator is blood component therapy (red blood cells, fresh-frozen plasma and platelets given together in a 1:1:1 unit ratio). The Cochrane risk of bias tool for randomised controlled trials and Risk Of Bias In Non-randomised Studies - of Interventions (ROBINS-I) for observation studies will be used to assess the risk of bias of included studies. We will use random-effects models for the pooling of studies. Interstudy heterogeneity will be assessed by the Cochran Q statistic, where p<0.10 will be considered statistically significant and quantified by I² statistic, where I² ≥50% will indicate substantial heterogeneity. We will perform subgroup and meta-regression analyses to assess geographical differences and other study-level factors explaining variations in the reported mortality risk. Results will be reported as risk ratios and their 95% CIs.

Ethics and dissemination: No ethics clearance is required as no primary data will be collected. The results will be presented at scientific conferences and published in a peer-reviewed journal.