BLOOD SALVAGE AFTER TOTAL HIP-ARTHROPLASTY

We performed a prospective, randomized study to determine the effect of postoperative collection and reinfusion of unwashed, filtered, salvaged blood on the transfusion requirements of 232 patients managed with a total hip replacement. Patients who were scheduled to have a primary or revision procedure were advised to predeposit two or four units of autologous blood, respectively, before the operation. In addition, intraoperative blood salvage was performed for all patients who had a revision procedure. The patients were randomly assigned to one of two groups: the first group was managed with postoperative blood salvage with use of the Autovac Postoperative Orthopaedic Autotransfusion Canister and the second, with closed suction drainage with use of the Hemovac system. In the first group, blood was collected from wound drains for four hours postoperatively; if at least 300 milliliters of blood was collected, the unwashed blood was reinfused through a microaggregate filter during a two-hour period. A maximum of 1000 milliliters of salvaged blood was reinfused; any blood that had not been reinfused within six hours after the beginning of collection was discarded. No complications or episodes of hypotension, confusion, cardiac or pulmonary compromise, febrile reaction, or coagulopathy were observed during or after the reinfusion of the unwashed, filtered, salvaged blood. No reinfusions were interrupted or discontinued. We found that postoperative reinfusion of unwashed, filtered, salvaged blood was associated with a decreased prevalence of homologous transfusion after a total hip replacement among patients for whom preoperatively donated autologous blood was not available. The prevalence for this group was four of fifteen compared with twenty-two (73 per cent) of thirty in a control group that was not managed with postoperative blood salvage. Postoperative reinfusion of unwashed, filtered, salvaged blood also was associated with a decreased prevalence of homologous transfusion among patients who had had a revision procedure (four [11 per cent] of thirty-six compared with fourteen [35 per cent] of forty in a control group). However, with the numbers available, postoperative reinfusion did not affect the prevalence of homologous transfusion among patients for whom preoperatively donated autologous blood was available after a primary total hip replacement, and we do not recommend its routine use for this group of patients.