Incidence of postoperative shivering comparing remifentanil with other opioids: a meta-analysis

Study Objective: To determine whether the administration of remifentanil increases the incidence of postoperative shivering in comparison with the administration of alfentanil, fentanyl, or sufentanil. Design: Meta-analysis. Setting: Operating room and postanesthesia care unit. Measurements: We performed a computerized search of articles on PubMed, MEDLINE, and Scopus. Meta-analysis was performed using Review Manager and the DerSimonian and Laird random-effects model. The pooled effect estimates for binary variables were calculated as relative risk (RR) values with 95% confidence intervals (CIs). Main Results: Eighteen randomized controlled trials met our inclusion criteria. Remifentanil was associated with a significantly increased incidence of postoperative shivering compared with other opioids (RR = 2.17; CI, 1.76-2.68; P < .00001; I-2 = 0.00%). A subgroup analysis of remifentanil compared with alfentanil, fentanyl, or sufentanil showed that only sufentanil had a similar rate of postoperative shivering incidence (RR = 2.13; CI, 0.67-6.74; P = .20; I-2 = 0.00%). Remifentanil administration was associated with a significant increase in the incidence of postoperative shivering compared with the administration of other opioids when both propofol (RR = 2.44; CI, 1.52-3.92; P = .0002; I-2 = 0.00%) and inhalation anesthesia drugs (RR = 2.45; CI, 1.46-4.11; P = .0007; I-2 = 0.00%) were used for anesthesia maintenance. In addition, the administration of remifentanil at both low (RR = 2.06; CI, 1.63-2.60; P < .00001; I-2 = 0.00%) and high dosages (RR = 2.77; CI, 1.67-4.57; P<.0001; I-2 = 0.00%) was associated with a significant increase in the incidence of postoperative shivering compared with the administration of other opioids. Conclusions: Our meta-analysis showed that remifentanil was associated with an increased incidence of postoperative shivering compared with alfentanil or fentanyl, but no significant difference was seen when compared with sufentanil. (C) 2015 Elsevier Inc. All rights reserved.