Effect of intermediate dose dexamethasone on post-operative pain in lumbar spine surgery: A randomized, triple-blind, placebo-controlled trial

Objectives: Dexamethasone has demonstrated analgesic properties and is used as an adjunctive pain agent for many procedures. We evaluated the efficacy of a single, intermediate dose of dexamethasone on post-operative analgesic consumption, and pain scores for lumbar spine surgery. Methods: Eighty patients aged between 18 and 70 scheduled for lumbar decompressive laminectomy were randomly allocated into two groups to receive either intravenous 0.2 mg/kg dexamethasone (group D = 40) or normal saline (group P = 40) before anesthetic induction. Post-operative total morphine consumption and the respective pain score at the PACU, 4, 6, 12, 24 and 48 h were evaluated. In addition, any adverse events were recorded. Results: Total post-operative morphine consumption within 48 h was significantly lower in group D (34.5 vs. 42.5 mg, p = 0.031); however, the respective morphine consumption at each assessment was similar between groups. The respective NRS pain score at rest and upon movement in both groups was not significantly different for any time comparison. The average NRS pain score at rest and upon movement within 48 h was similar in both groups (i.e., NRS at rest Group D 3.6 vs. Group P 3.8, p = 0.936, and NRS for movement Group D 6.2 vs. Group P 6.3, p = 0.791). The adverse events within 48 h were also similar and serious complications (i.e., respiratory depression or surgical infection) were not found in either group. Conclusion: A single, intermediate dose of dexamethasone before anesthetic induction could minimally decrease post-operative morphine consumption within 48 h after lumbar decompressive laminectomy without any effect on the pain score.