Three-in-One Nerve Block With Different Concentrations of Bupivacaine in Total Knee Arthroplasty. Randomized, Placebo-Controlled, Double-Blind Trial.

Pain after total knee arthroplasty may be severe and lead to adverse outcomes. Using 2 concentrations of bupivacaine, we investigated 3-in-1 nerve block's effect on pain control, narcotic use, sedation, and patient satisfaction. One hundred five patients undergoing unilateral total knee arthroplasty were randomized into 3 groups: low-dose or high-dose bupivacaine or placebo. Ninety-nine patients completed the study. Three-in-1 nerve block reduced patient-controlled opioid analgesia usage and improved pain relief in the early postoperative period but had little effect beyond postoperative day 1. There were no significant differences among groups with respect to nausea or sedation. Patients in each group exhibited high overall satisfaction. Low-dose bupivacaine was superior to high-dose bupivacaine for pain relief, narcotic consumption, and patient satisfaction in the early postoperative period.