Use of Ketamine Infusions for Treatment of Complex Regional Pain Syndrome: A Systematic Review

Abstract

Background: This systematic review aims to review clinical studies on the use of ketamine infusion for patients with treatment-resistant Complex Regional Pain Syndrome (CRPS). Methods: The following systematic review was registered on PROSPERO (CRD42021228470). Studies for the systematic review were identified through 3 databases; PubMed, CINAHL, and Cochrane Review. Inclusion criteria for studies consisted of randomized clinical trials or cohort studies that conducted trials on the use of ketamine infusion for pain relief in patients with Complex Regional Pain Syndrome (CRPS). Exclusion criteria for studies included any studies that were systematic review, meta-analyses, case reports, literature reviews, or animal studies. In the included studies, the primary outcome of interest was post drug administration pain score. Results: In this systematic review, 14 studies met the inclusion criteria and were reviewed. In these studies, the dosage of ketamine infusion used ranged from 0.15 mg/kg to 7mg/kg with primary indication being treatment of Complex Regional Pain Syndrome (CRPS). In 13 of the studies, ketamine infusion resulted in a decrease in pain scores and relief of symptoms. Conclusions: Patients who received Ketamine infusion for treatment-resistant CRPS self-reported adequate pain relief with treatment. This suggests that ketamine infusion may be a useful form of treatment for patients with no significant pain relief with other conservative measures. Future large-scale studies, including randomized double-blind placebo-controlled trials on the use of ketamine infusion for CRPS must be conducted in a large-scale population to further assess the effectiveness of ketamine infusion in these populations.