Combination of Autologous Transfusion and Retrograde Autologous Priming Decreases Blood Requirements

In a prospective study, 60 patients posted for coronary artery bypass graft (CABG) surgery on cardiopulmonary bypass (CPB) were assigned to 2 groups of 30 each. (group A =combination of acute normovolaemic haemodilution (ANH) and retrograde autologous priming (RAP), group B=control). The aim was to investigate whether retrograde autologous priming reduces haemoditution as compared to control cases. Patients who had a history of previous cardiac surgery and patients with severe left ventricular dysfunction, were excluded. Group A patients were subjected to pre-CPB intraoperative autologous blood collection prior to heparin administration. Heparin was given (300IU/Kg) and the aorta was cannulated. In addition, prior to bypass, if the patients had a systolic BP>100 mm Hg, 300cc of their blood was withdrawn in a retrograde manner via aortic cannula into the CPB circuit up to the arterial filter, while the ‘displaced’ asanguinous prime was diverted into a transfer bag. The total bank blood (whole blood) used intra-op was 26 units in the study group [mean 0.86 unit per patient] versus 52 units in the control group (mean 1.73 units per patient) (P<0.001). Blood components and products were not used in this study. The average fall in haematocrit (Hct) on CPB was 27.03% in the study group versus 39.5% in the control group (P < 0.001). Thus retrograde autologous griming in combination with autologus transfusion significantly reduces the need for bank blood.