A prospective randomised controlled trial of postoperative autotransfusion with and without a heparin-bonded circuit.

Autotransfusion has been included in the routine protocol in some units as an effort towards blood conservation. In this study we aimed to measure the efficacy and limitations of autotransfusion and whether a heparin-bonded circuit had any advantage. One hundred five pa- tients were randomised to one of three post-operative treatments. Group 1 (n = 34) was not autotrans- fused whereas groups 2 (n = 36) and 3 (n= 35) received autotransfusion with the circuit of group 3 coated with heparin. Homologous blood and blood products were given according to strict protocols identical for all groups, Transfused and circulating blood was analysed for haemostatic variables and the requirement for ho- mologous blood was recorded. Auto- transfused blood contained no intact platelets and very high levels of D-Dimers (a peptide fragment re- leased when fibrin is lysed) which resulted in high levels of systemic D-Dimers in patients receiving auto- transfusion. Flow cytometric analy- sis revealed that whilst platelet gly-