The influence of local infiltration analgesia after total hip replacement. A randomized clinical trial.

To determine whether local infiltration analgesia by catheter infusion was superior to conventional analgesia in terms of postoperative pain control after THR. A randomized double-blind clinical trial was performed. There were four groups based on catheter placement and the infusion constituents : 1) Intraarticular catheter + anesthetics ; 2) Intraarticular catheter +placebo ; 3) Subfascial catheter + anesthetics ; 4) Subfascial catheter + placebo. The anesthetic infusion contained bupivacaine (bolus + continuous perfusion up to 36 hours). The placebo solution was physiological serum. The same conventional analgesic schedule was prescribed to all patients. Pain was evaluated by means of PCA shots and the VAS. Side effects, time to start rehabilitation and time to discharge were also analyzed. 100 patients (25 for group). Mean age was 67 years old (SD 12 y/o) and 53% were male. Mean PCA shots was 27 [range 2-87] and mean VAS was 1 [range 0-7]. No differences were found (p>0.05) when these variables were compared between the groups. The use of LIA with bupivacaine using a catheter infusion does not provide better pain control after THR.