Postoperative autologous blood salvage drains--are they useful in primary uncemented hip and knee arthroplasty? A prospective study of 186 cases.

There are nearly 43,000 hip replacements and 33,000 knee replacements performed each year in the United Kingdom. Many of these require a blood transfusion. However, there has been increased public concern about the safety of blood transfusion and various techniques are used to decrease the need for allogenic transfusion. Postoperative blood salvage and reinfusion is one of them. We studied 186 consecutive patients who underwent unilateral uncemented hip or knee arthroplasty. Ninety-four had re-infusion drains and 92 had suction drains. We have compared the allogenic transfusion requirements for the two groups. We have analyzed patient and operative factors to determine whether they are predictive for risk of allogenic blood transfusion. Cost analysis was performed to determine whether the use of a re-infusion drain is a cost effective technique. Re-infusion drains significantly decreased the requirements for allogenic blood transfusion (p = 0.001). Twenty-one percent of the re-infusion drain group and 45.7 % of the suction drain group required allogenic blood transfusion. The only preoperative factor that determined whether the patient required allogenic blood transfusion was pre-operative haemoglobin. We found that age, gender, type of surgery (hip replacement or knee replacement) and whether the patient had tourniquet or not (in knee replacement) did not alter the requirements for allogenic blood transfusion. The mean transfusion costs were slightly less for re-infusion drain group (ł 182.70 per patient for re-infusion drain group and ł 196.75 per patient for suction drain group, p = 0.009). The hospital stay was also significantly reduced (11.0 days for re-infusion drain group as opposed to 12.6 days for suction drain group (p = 0.0248). Based on these findings, re-infusion drains appear as a cost effective means of reducing the requirement for allogenic blood transfusion following primary hip and knee arthroplasty.