Reducing Blood Loss after Total Hip Arthroplasty: A Prospective Randomised Controlled Trial to Evaluate the Efficacy of Temporarily Clamping Drains

The purpose of the study is to primarily answer the question as to whether temporarily clamping the drain for one hour after total hip replacement reduces blood loss. Many surgeons use this technique, as it is perceived that it creates a tamponade effect in the closed wound, promoting clotting and thereby reducing blood loss. There are no studies to support this practice after hip replacement. We have designed and conducted a randomised controlled trial. Fifty-six patients undergoing total hip replacement had drains placed in their wounds. They were randomised into two groups: half had their drain temporarily clamped for one hour and then the drain opened. The other half had the drain opened immediately after wound closure. The primary outcome measure was volume of drainage at 24 hours and the secondary outcome measures were transfusion requirements and postoperative haemoglobin reduction.

No differences were seen between controlled groups for the volume of drainage (413±152 mL vs. 378±141 mL, standard deviation, SD; p=0.38), the transfusion requirement (8/28 in each group received 2 units of packed red cells), or the postoperative haemoglobin drop (not transfused: 3.1±1.3 vs. 3.6±1.5 g/dL, SD, p=0.29; and transfused 2 units: 0.8±1.4 vs. 1.4±1.2 g/dL, SD, p=0.38). The data from this trial suggests that the practice of clamping drains does not give a beneficial effect in terms of reduced blood loss. This is the first trial of its kind to explore this question in total hip replacement surgery.