Effect of drain pressure in total knee arthroplasty.

PURPOSE To study the effect of drain suction pressure on drainage volume, decrease in haemoglobin level, blood transfusion, and wound complications following total knee arthroplasty. METHODS Primary total knee arthroplasty for degenerative osteoarthritis was performed in 60 (49 female and 11 male) patients. Patients were randomised for high-pressure (600 mm Hg) or low-pressure (350 mm Hg) postoperative suction drainage. Drain output was recorded daily and the drain removed after 48 hours. Postoperative haemoglobin level was measured on the evening of the operation day and on postoperative day 2. RESULTS The high-pressure group had a significantly higher drainage volume and decrease in haemogloblin level than the low-pressure group. However, there was no significant difference between groups in the transfusion rate, number of units of blood transfused, wound discharge, or Knee Society knee and function scores. No wound infection was detected in any patient. CONCLUSION. Low-pressure suction drainage results in less blood loss without a significant increase in wound complications.