Intraoperative Ketamine in Total Knee Arthroplasty Does Not Decrease Pain and Narcotic Consumption: A Prospective Randomized Controlled Trial.

Background: Multiple studies have demonstrated that ketamine, a glutamate receptor blocker, may decrease postoperative pain in abdominal and orthopedic surgeries. However, its role with spinal anesthesia and total knee arthroplasty (TKA) remains unknown. The purpose of this study is to determine the efficacy of subanesthetic dosing of ketamine during TKA on postoperative pain and narcotic consumption.