Impact of pregabalin on acute and persistent postoperative pain: a systematic review and meta-analysis.

We performed this systematic review to assess the analgesic efficacy of perioperative pregabalin. Subgroup analyses and meta-regression were performed to assess the impact of individual dose and frequency of pregabalin administration on analgesic efficacy. We included 55 studies. When all doses and administration regimens were combined, pregabalin was associated with a significant reduction in pain scores at rest and during movement and opioid consumption at 24 h compared with placebo {mean difference [95% confidence interval (CI)]=-0.38 (-0.57, -0.20), -0.47 (-0.76, -0.18), and -8.27 mg morphine equivalents (-10.08, -6.47), respectively}. Patients receiving pregabalin had less postoperative nausea and vomiting and pruritus compared with placebo [relative risk (RR) (95% CI)=0.62 (0.48, 0.80) and 0.49 (0.34, 0.70), respectively]. Sedation, dizziness, and visual disturbance were more common with pregabalin compared with placebo [RR (95% CI)=1.46 (1.08, 1.98), 1.33 (1.07, 1.64), and 3.52 (2.05, 6.04), respectively]. All doses of pregabalin tested (≤75, 100-150, and 300 mg) resulted in opioid sparing at 24 h after surgery. There were no significant differences in acute pain outcomes with pregabalin 100-300 mg between single preoperative dosing regimens and those including additional doses repeated after surgery. Data were insufficient to reach conclusions regarding persistent pain, but limited data available from two studies suggested that pregabalin might be effective for the reduction of neuropathic pain. In conclusion, this review suggests that pregabalin improves postoperative analgesia compared with placebo at the expense of increased sedation and visual disturbances.

Impact of perioperative dexamethasone on postoperative analgesia and side-effects: systematic review and meta-analysis.

BACKGROUND: The analgesic efficacy and adverse effects of a single perioperative dose of dexamethasone are unclear. We performed a systematic review to evaluate the impact of a single i.v. dose of dexamethasone on postoperative pain and explore adverse events associated with this treatment. METHODS: MEDLINE, EMBASE, CINAHL, and the Cochrane Register were searched for randomized, controlled studies that compared dexamethasone vs placebo or an antiemetic in adult patients undergoing general anaesthesia and reported pain outcomes. RESULTS: Forty-five studies involving 5796 patients receiving dexamethasone 1.25-20 mg were included. Patients receiving dexamethasone had lower pain scores at 2 h {mean difference (MD) -0.49 [95% confidence interval (CI): -0.83, -0.15]} and 24 h [MD -0.48 (95% CI: -0.62, -0.35)] after surgery. Dexamethasone-treated patients used less opioids at 2 h [MD -0.87 mg morphine equivalents (95% CI: -1.40 to -0.33)] and 24 h [MD -2.33 mg morphine equivalents (95% CI: -4.39, -0.26)], required less rescue analgesia for intolerable pain [relative risk 0.80 (95% CI: 0.69, 0.93)], had longer time to first dose of analgesic [MD 12.06 min (95% CI: 0.80, 23.32)], and shorter stays in the post-anaesthesia care unit [MD -5.32 min (95% CI: -10.49 to -0.15)]. There was no dose-response with regard to the opioid-sparing effect. There was no increase in infection or delayed wound healing with dexamethasone, but blood glucose levels were higher at 24 h [MD 0.39 mmol litre(-1) (95% CI: 0.04, 0.74)]. CONCLUSIONS: A single i.v. perioperative dose of dexamethasone had small but statistically significant analgesic benefits.