The Effect of Intraoperative Methadone Compared to Morphine on Postsurgical Pain: A Meta-Analysis of Randomized Controlled Trials

Figure 5

Random effects meta-analysis evaluating the effect of intraoperative methadone on nausea and vomiting compared to the control. Squares to the right of the middle vertical line indicate that intraoperative methadone was associated with increased odds of nausea, whereas squares to the left of the middle vertical line show that intraoperative methadone was associated with decreased odds of nausea. The horizontal lines represent the 95% CI, and the diamond shape represents the overall effect of intraoperative methadone on postoperative nausea and vomiting compared to the control. CI = confidence interval.