Perioperative single dose systemic dexamethasone for postoperative pain: a meta-analysis of randomized controlled trials.

BACKGROUND Dexamethasone is frequently administered in the perioperative period to reduce postoperative nausea and vomiting. In contrast, the analgesic effects of dexamethasone are not well defined. The authors performed a meta-analysis to evaluate the dose-dependent analgesic effects of perioperative dexamethasone. METHODS We followed the PRISMA statement guidelines. A wide search was performed to identify randomized controlled trials that evaluated the effects of a single dose systemic dexamethasone on postoperative pain and opioid consumption. Meta-analysis was performed using a random-effect model. Effects of dexamethasone dose were evaluated by pooling studies into three dosage groups: low (less than 0.1 mg/kg), intermediate (0.11-0.2 mg/kg) and high (≥ 0.21 mg/kg). RESULTS Twenty-four randomized clinical trials with 2,751 subjects were included. The mean (95% CI) combined effects favored dexamethasone over placebo for pain at rest (≤ 4 h, -0.32 [0.47 to -0.18], 24 h, -0.49 [-0.67 to -0.31]) and with movement (≤ 4 h, -0.64 [-0.86 to -0.41], 24 h, -0.47 [-0.71 to -0.24]). Opioid consumption was decreased to a similar extent with moderate -0.82 (-1.30 to -0.42) and high -0.85 (-1.24 to -0.46) dexamethasone, but not decreased with low-dose dexamethasone -0.18 (-0.39-0.03). No increase in analgesic effectiveness or reduction in opioid use could be demonstrated between the high- and intermediate-dose dexamethasone. Preoperative administration of dexamethasone appears to produce a more consistent analgesic effect compared with intraoperative administration. CONCLUSION Dexamethasone at doses more than 0.1 mg/kg is an effective adjunct in multimodal strategies to reduce postoperative pain and opioid consumption after surgery. The preoperative administration of the drug produces less variation of effects on pain outcomes.