The efficacy of NMDA receptor antagonists for preventing remifentanil-induced increase in postoperative pain and analgesic requirement: a meta-analysis

Abstract

Background: Meta-analysis was performed to evaluate the preventive effects of N-methyl-D-aspartate (NMDA) receptor antagonists on remifentanil-induced increase in postoperative pain and analgesic requirement in patients.

Methods: Pubmed, EMBase, Springer and the Cochrane Controlled Trials Register were searched to identify all randomized controlled trials (RCTs) published to November 2010 which investigated the preventive effects of NMDA receptor antagonists on remifentanil-induced postoperative hyperalgesia and/or tolerance. The studies listed at the end of these articles as reference were also searched. Two authors independently assessed the quality of each study met the inclusion criteria and extracted data. Then Meta-analysis was perfomed using RevMan 5.0 software. The outcomes analyzed were the postoperative analgesic consumption, pain intensity scores, time to first analgesic request, and the incidence of adverse effects.

Results: A total of 623 patients (223 in the ketamine group, 87 in the magnesium group and 313 in the control group) from 14 prospective RCTs were included in the Meta-analysis. Administration of NMDA receptor antagonists reduced the pain scores at 4 hr after operation (P<0.05), and the standardized mean differences (SMD) was -0.21 (95% confidence interval was -0.41 to -0.01). There were no significant differences in postoperative analgesic consumption, pain scores at other time points, time to first analgesic request and the incidence of adverse effects (P>0.05). Further subgroup analyses based on the type of intervention showed that the results were almost the same.

Conclusion: These data do not support the use of NMDA receptor antagonists, ketamine and magnesium sulfate to prevent the development of remifentanil-induced postoperative hyperalgesia and tolerance.