Ketamine reduces pain and opioid consumption after total knee arthroplasty: A meta-analysis of randomized controlled studies.

OBJECTIVE

To examine the analgesic efficacy and safety of ketamine after total knee arthroplasty.

METHODS

We searched for all articles on ketamine in patients with total knee arthroplasty in electronic databases, including PubMed, Embase, Ovid, Cochrane Library, Web of Science, CNKI, Wanfang Data, and VIP, up to the February 2019. Randomized controlled trials comparing ketamine and the placebo for pain management after total knee arthroplasty were utilized. The outcome measurements consist of the pain score, opioid consumption, length of hospitalization and postoperative complications. All data analyses were conducted using STATA 13.0. Cochrane Collaboration's tool was adopted to assess the risk of bias.

RESULTS

A total of six randomized controlled trials were included in the meta-analysis. The present meta-analysis demonstrated that there were significant differences between the two groups regarding the pain score within the first 24 postoperative hours. Ketamine was associated with a significant reduction of cumulative morphine consumption. Notably, ketamine could significantly decrease the incidence of nausea and vomiting without increasing the risk of thrombosis.

CONCLUSION

Ketamine is effective in reducing pain and cumulative morphine consumption during the early post-operative period after total knee arthroplasty. In addition, the use of ketamine is associated with a lower incidence of adverse effects.