Bupivacaine bolus injection versus placebo for pain management following total knee arthroplasty.

Following surgery, total knee arthroplasty (TKA) patients experience considerable pain. All available effective analgesia agents produce some unwanted side effects. Sixty consenting elective TKA patients were randomized to receive bupivacaine 20 mL 0.5% (100 mg) or 20 mL normal saline injected into the joint space after capsule closure. Patients were interviewed up to 24 hours after surgery for pain and pain relief. Narcotic usage was recorded. The bupivacaine group had lower pain scores and reduced narcotics during the 24-hour period, with a 23-minute shorter time to discharge from the postanesthesia care unit than the placebo group (P =.02). Although a bupivacaine bolus injected at capsule closure results in decreased pain levels (P =.07) and narcotic consumption (P =.09), it is not statistically significantly better than placebo.