Analgesic Effects of Adding Dexamethasone to Bupivacaine in Adductor Canal Block for Postoperative Pain After Total Knee Arthroplasty : A Randomized Controlled Clinical Trial

Abstract

     Postoperative pain after Total Knee Arthroplasty can be burdensome. Adductor canal block as multimodal analgesia have become increasingly use because of their low frequency of complication and excellence pain relief. Dexamethasone is commonly used in anesthesia to reduced postoperative pain and opioid requirement. The objective of this study is to evaluate effect of addition Dexamethasone to Bupivacaine on postoperative analgesia after Total Knee Arthroplasty. This research was a randomized, double-blinded, controlled clinical trial was conducted from November 2016 – May 2017. Seventy four patients scheduled for elective TKA in Nan hospital were randomized allocated into two groups to receive 0.25% bupivacaine and dexamethasone 4 มก. or 0.25% bupivacaine. Student t- test and Wilcoxon signed Rank test were used to compared duration of analgesia, postoperative pain score, pain score at 24 hours and total morphine consumption at first 24 hours.

     Result: There were no signification difference in demographic data, surgical time and tourniquet time. There was no difference in first postoperative pain score. However the group received 0.25% bupivacaine and dexamethasone 4 mg had significantly longer duration of analgesia (664.72±116.53 vs 446.62±124.86, p = 0.05) and had lower pain score at 24 hour (2.40 ± 1.8 vs 3.73±1.98, p = 0.003). Total morphine consumption were less in dexamethasone group 24 hours after surgery (2.68 ±1.85 vs 4.32±3.37, p = 0.023)

Keyword:  Adductor Canal Block, Total Knee Arthroplasty, Dexamethasone, Bupivacaine, Post-operative pain