Fig. 4

Incidence of postoperative nausea and vomiting at 24 h after surgery. Random-effects meta-analysis evaluating the effect of erector spinae plane block on nausea and vomiting compared to control. Squares to the right of the middle vertical line indicates that erector spinae plane block was associated with increased odds of nausea, whereas squares to the left of the middle vertical line show that erector spinae plane block was associated with decreased odds of nausea. The horizontal lines represent the 95% CI and the diamond shape represents the overall effect of erector spinae plane block on postoperative nausea and vomiting compared to control. CI = confidence interval