Whole blood versus red cell concentrates for children with severe anaemia: a secondary analysis of the Transfusion and Treatment of African Children (TRACT) trial

Abstract

Background: The multicentre Transfusion and Treatment of African Children (TRACT) trial established best evidence on the timing of transfusion in children with uncomplicated anaemia (haemoglobin 4-6g/dl) and optimal volume (20 versus 30ml/kg whole blood (or 10 vs 15ml/kg red cell concentrates) for transfusion in children hospitalised with severe anaemia (Hb <6g/dl) on Day 28 mortality (primary endpoint) and secondary endpoints including safety. As evidence on the safety of blood components is limited we undertook a secondary analysis comparing children receiving whole blood versus red cell concentrates as their initial transfusion on clinical outcomes. Methods : This analysis includes 3188 children with severe anaemia (Hb <6g/dl) who received either whole blood or red cell concentrates. Whole blood or cell concentrates were issued routinely by the blood transfusion services, but not prespecified on the request form. The impact of blood pack type on haematological correction, re-transfusion, and other clinical endpoints was explored using multivariate regression models. Findings: 1632/3992 (41%) transfusions in 3188 children were whole blood. Compared with whole blood, children receiving cell concentrates in their first transfusion had less haemoglobin recovery at 8 hours (packed cells mean(95%CI): -1.3(-1.5,-1.0) 20ml/kg arm,-1.4(-1.6,-1.1) 30ml/kg; settled cells mean(95%CI) -1.1g/dl(-1.2,-0.9) 20ml/kg arm, -1.5g/dl(-1.7,-1.3) 30ml/kg arm; p<0.001 for pack type comparisons, p=0.003 heterogeneity by arm), higher odds of receiving a second transfusion [ORs 2.32 (95%CI 1.30,4.12) and 2.97 (2.18,4.05) respectively; p<0.001], and had a longer time to discharge [sub-Hazard Ratios 0.94 (95%CI 0.81,1.10) and 0.86 (95% CI 0.79,0.94) respectively; p=0.002]. No child developed features of cardio-pulmonary overload. Interpretation: Whole blood is safe to use in children, resulting in superior aematological correction, less repeat transfusion and shorter hospital stays. These findings have substantial cost implications for both blood transfusion and health services. Nevertheless, a clinical trial comparing whole blood transfusion to red cell concentrates maybe needed to convince policy makers.