Massive transfusion protocols in paediatric trauma population: A systematic review

Our main objective was to review the literature to answer the following questions regarding paediatric massive transfusion (PMT) protocols: (a) How is PMT defined?; (b) Which blood product ratios have been investigated, and what is their effect on outcomes?; and (c) What evidence exists regarding PMT outcomes?The PRISMA guidelines were used. We searched PubMed, Google Scholar, Cochrane Library, EMBASE, Wiley Online Library and Ovid. Articles were screened for inclusion based on relevance to PMT. Articles were assessed for study design, presence of established/tested PMT, PMT definition, PMT activation criteria and Transfusion Ratios for the final determination of article inclusion.Our search produced 3213 articles, with 33 included for final review. Existing definitions of PMT are based on volume administered/kg but vary in timeframe criteria (over 4 hours vs 24 hours). Some studies have investigated "high" balanced transfusion ratios as seen in adults (1:1 FFP:pRBC), with a few showing statistically significant improvement in paediatric mortality vs lower ratios. PMT protocol implementation has not been shown to consistently reduce paediatric trauma mortality across multiple centres. However, other operational aspects, such as reduced time to first transfusion, are apparent benefits.There is poor consensus over the definition of PMT. Definitions that involve early recognition have the most promise for practice and future studies. Evidence supporting an optimal blood product ratio in PMT is also lacking but trends towards supporting balanced approaches. Implementation of PMT protocols has been limited in showing significant improvement of overall paediatric trauma mortality but may reduce associated morbidity.