Postoperative autotransfusion of mediastinal shed blood does not influence haemostasis after elective coronary artery bypass grafting

Abstract

Objectives: The rationale of using autotransfusion of mediastinal shed blood after cardiac surgery is to preserve haemoglobin levels and reduce the need for allogenic blood transfusions. However, the method is controversial and its clinical value has been questioned. We hypothesised that re-transfusion of mediastinal shed blood instead impairs haemostasis after routine coronary artery bypass grafting and thus increases postoperative bleeding.

Methods: Seventy-seven consecutive elective coronary artery bypass surgery patients (mean age 67±9 years, 77% men) were included in a prospective, randomised controlled study. The patients were randomised to postoperative re-transfusion of mediastinal shed blood (n=39) or to a group where mediastinal shed blood was discarded (n=38). Primary end point was bleeding during the first 12 postoperative hours. Secondary end points were postoperative transfusion requirements, haemoglobin levels, thrombo-elastometric variables and plasma concentrations of interleukin-6, thrombin-anti-thrombin complex and D-dimer.

Results: Mean re-transfused volume in the autotransfusion group was 282±210 ml. There was no difference in postoperative bleeding (median 394 ml (interquartile range 270-480) vs 385 (255-430) ml, p=0.69), proportion of patients receiving transfusions of blood products (11/39 vs 11/38, p=0.95), haemoglobin levels 24h after surgery (116±13 vs 116±14 g l(-1), p=0.87), thrombo-elastometric variables, interleukin-6 (219±144 vs 201±144 pg ml(-1), p=0.59), thrombin-anti-thrombin complex (11.0±9.1 vs 14.8±15, p=0.19) or D-dimer (0.56±0.49 vs 0.54±0.44, p=0.79) between the autotransfusion group and the no-autotransfusion group.

Conclusions: Autotransfusion of small-to-moderate amounts of mediastinal shed blood does not influence haemostasis after elective coronary artery bypass grafting.