Low- or high-vacuum drains in hip arthroplasty? A randomized study of 73 patients

We compared the effect of low-vacuum and high-drains on blood loss and blood transfusions in a randomized study of 73 patients undergoing primary hip arthroplasties. During the first postoperative hour, the high-vacuum drains evacuated more blood than the low-vacuum ones, median 135 and 35 mL (p < 0.001). After that, the rate of blood loss into the drains was approximately the same. Median blood losses into the drains after 24 hours were 570 mL in the high-vacuum group and 480 mt in the low-vacuum group (p = 0.03). Corresponding values after 48 hours were 785 mL and 585 mL (p = 0.002). The hemoglobin concentration in the drain fluid during the second postoperative day was lower in the high-vacuum group, indicating a more serous discharge. Our findings indicate that drains should be removed within 24 hours. High-vacuum drains evacuate more blood initially but may cause more damage to the tissues, especially if they are left for more than 24 hours. We found no significant difference in postoperative hemoglobin decrease or in the number of blood transfusions and wound complications in the 2 groups.