Prospective randomized study after the use of drains in total knee arthroplasty with implant.

Objective: to compare the laboratorial results of opening suction drainage 6 hours and 12 hours after total knee arthroplasty surgery.
Methods: prospective and randomized study in 88 patients undergoing with total knee arthroplasty in two groups: in one group the opening suction drainage was performed 6 hours (n = 45) after the surgery and in the other 12 hours (n = 43) after the surgery.
Results: the outcome was a significant fall in the three laboratorial variables (hemoglobin, red blood cells and hematocrit) between the pre and post-operative in the total sample and in the six and 12 hour opening suction drainage groups. In the group with opening suction drainage after 12 hours, the drainage volume was significantly lower than in the group with opening suction drainage after 6 hours (p = 0.0003). However, no significant difference was observed in the absolute delta of the laboratorial variables between the two groups.
Concluasion: the opening suction drainage in six and 12 hours did not show significant difference from the laboratorial values although the volume of the blood drained was higher in the opening suction drainage in six hours.