Is perioperative colloid infusion more effective than crystalloid in preventing postoperative nausea and vomiting?: A systematic review and meta-analysis

BACKGROUND: Adequate intravenous fluid replacement is recommended as an effective nonpharmacologic strategy for reducing postoperative nausea and vomiting (PONV), one of the most common and stressful complications of general anesthesia. We aimed to evaluate the effect of hydration, according to the type of fluid, on PONV as previous studies have reported inconsistent results. METHODS: We performed a systemic review and meta-analysis of randomized controlled trials (RCTs) comparing infusion of colloid with that of crystalloid in terms of PONV incidence and the need for rescue antiemetic therapies for 24 hours after surgery under general anesthesia. The effect of fluid infusion according to the duration of anesthesia was also examined. A literature search was performed, using MEDLINE, Excerpta Medica Database, Cochrane Central Register of Controlled Trials, Web of Science, and Scopus, up to February 2018. RESULTS: We included 8 RCTs. Compared with the crystalloid infusion, perioperative colloid infusion did not reduce PONV incidence, with a relative risk of 0.87 (95% confidence interval [CI], 0.60-1.25). However, subgroup analysis by duration of anesthesia showed a statistically significant subgroup effect (P = .04, I = 77.4%), suggesting that the effect of colloid differed from that of crystalloid depending on the duration of anesthesia. In the subgroup that underwent anesthesia for more than 3 hours, in which the patients had mostly undergone abdominal surgeries, colloid infusion significantly reduced the incidence of PONV compared with crystalloid infusion (RR, 0.69; 95% CI, 0.53-0.89). In the subgroup that underwent anesthesia for <3 hours, colloid infusion did not reduce the incidence of PONV compared with crystalloid infusion (RR, 1.32; 95% CI, 0.76-2.27). The requirement for antiemetics was comparable between colloid and crystalloid infusions, with an RR of 0.93 (95% CI, 0.55-1.58). CONCLUSION: Colloid administration had a more preventive effect on PONV than crystalloid administration in patients undergoing abdominal surgery under general anesthesia for more than 3 hours but did not show a preventive effect in patients undergoing anesthesia for