Is intraoperative dexmedetomidine a new option for postoperative pain treatment? A meta-analysis of randomized controlled trials.

In the present meta-analysis, we assessed the efficacy and safety of intravenous administration of dexmedetomidine (DEX) compared with placebo or opioids for acute postoperative pain treatment in adults undergoing surgery. The meta-analysis was performed according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement and the recommendations of the Cochrane Collaboration. Randomized controlled trials investigating perioperative administration of DEX were included. For dichotomous outcomes relative risks (RR; 95% confidence intervals [CI]) and for continuous outcomes mean differences (MD; 95% CI) were calculated. Twenty-eight randomized controlled trials including 1420 patients were finally included. Patients treated with DEX reported lower postoperative pain intensity (MD1h postoperatively: -1.59U (numeric rating scale: 0 to 10) 95% CI: -2.37 to -0.82; P=.000001) and showed a lower postoperative opioid consumption (MD24h postoperatively: -17.24mg; 95% CI: -24.38 to -10.10; P=.00001) compared with placebo. Additionally, the DEX group showed a lower RR for opioid-related adverse events (e.g. RRNausea (postanesthesia care unit): 0.66; 95% CI: 0.43 to 1.02; P=.06). The most common adverse event in patients treated with DEX was intraoperative bradycardia with a RR of 2.66 (RR: 2.66; 95% CI: 1.54 to 4.58; P=.0004) compared with placebo. There is evidence that DEX administration leads to lower postoperative pain, reduced opioid consumption, and a lower risk for opioid-related adverse events. The comparison of DEX vs opioids for postoperative pain treatment is less clear due to limited data. The most common adverse event was intraoperative bradycardia after DEX administration. Therefore cautions in patients at risk are warranted, and large trials focusing on long-term outcomes after intraoperative DEX use are needed.

Efficacy and safety of paravertebral blocks in breast surgery: a meta-analysis of randomized controlled trials.

BACKGROUND: Thoracic paravertebral blocks (PVBs) are successfully performed for pain management after breast surgery. The aim of the present quantitative systematic review was to assess the efficacy and adverse events of PVB in women undergoing breast surgery. METHODS: The systematic search, data extraction, critical appraisal, and pooled analysis were performed according to the PRISMA statement. The relative risk (RR), mean difference (MD), and their corresponding 95% confidence intervals (CIs) were calculated using the RevMan statistical software for dichotomous and continuous outcomes, respectively. Pain scores were converted to a scale ranging from 0 (no pain) to 10 (worst pain). RESULTS: Fifteen randomized controlled trials (published between 1999 and 2009) including 877 patients met the inclusion criteria. There was a significant difference in worst postoperative pain scores between PVB and general anaesthesia (GA) at <2 h (MD: -2.68; 95% CI: -3.33 to -2.02; P<0.00001), 2-24 h (MD: -2.34; 95% CI: -2.42 to -1.12; P<0.00001), and 24-48 h (MD: -1.75; 95% CI: -3.19 to 0.31; P=0.02). Accordingly, lower pain scores were observed for combined PVB with GA compared with GA alone for <2 h (MD: -1.87; 95% CI: -2.53 to -1.21; P<0.00001), 2-24 h (MD: -2.21; 95% CI: -3.07 to -1.35; P<0.00001), and 24-48 h (MD: -1.80; 95% CI: -2.92 to 0.68; P=0.002). The RR for the reported adverse events (e.g. pneumothorax) was low. CONCLUSIONS: There is considerable evidence that PVB in addition to GA or alone provide a better postoperative pain control with little adverse effects compared with other analgesic treatment strategies.