Mild hypothermia increases blood loss and transfusion requirements during total hip arthroplasty

Summary Background In-vitro studies indicate that platelet function and the coagulation cascade are impaired by hypothermia. However, the extent to which perioperative hypothermia influences bleeding during surgery remains unknown. Accordingly, we tested the hypothesis that mild hypothermia increases blood loss and allogeneic transfusion requirements during hip arthroplasty. Methods Blood loss and transfusion requirements were evaluated in 60 patients undergoing primary, unilateral total hip arthroplasties who were randomly assigned to normothermia (final intraoperative core temperature 36·6 [0·4]°C) or mild hypothermia (35·0 [0·5]°C). Crystalloid, colloid, scavenged red cells, and allogeneic blood were administered by strict protocol. Findings Intra- and postoperative blood loss was significantly greater in the hypothermic patients: 2·2 (0·5) L vs 1·7 (0·3) L, p