The efficacy of high volume of local infiltration analgesia for postoperative pain relief after total hip arthroplasty under general anaesthesia - A randomised controlled trial

Abstract

Background and aimResearch regarding patients undergoing total hip arthroplasty (THA) has shown no significant difference in postoperative pain with or without the use of local infiltration analgesia (LIA). The aim was to evaluate whether intra-operative LIA with Ropivacaine in patients undergoing THA under general anaesthesia reduces postoperative pain. MethodA randomised, placebo-controlled trial. Forty patients undergoing elective primary THA under general anaesthesia were allocated to an intervention group (RG) who received 150 ml of LIA or a placebo group (CG) who received 150 ml of saline solution. ResultsThere were no differences in demographic data or duration of anesthesia. The total mean dose of morphine given was 16 ± 12 mg (RG) and 13 ± 9 mg (CG) (p=0.238). Pain scores (Numeric rating scale, NRS) on arrival at the PACU (time 0) were Md 1 in the RG groupvs Md 5 in the CG group (p = 0.026). During the first 2 h the Md NRS values in the RG group were ≤3 whereas the Md values in the CG were ≥3. No significant differences in NRS were found at 1–6 h after arrival at the PACU. ConclusionOur study suggests that there is a positive effect of LIA on pain scores within the first hour postoperatively in patients undergoing elective primary THA under general anaesthesia.