1. Effect estimates for single studies.

Outcome	Study/Participant	Statistical method	Effect estimate [95% CI]	P value
Pain in the PACU (VAS)	1/n = 62	MD	‐1.00 [‐9.82 to 7.82]	0.82
Pain at 1 to 6 hours (VAS)	1/n = 62	MD	‐2.20 [‐10.62 to 6.22]	0.61
Pain at 6 to 24 hours (VAS)	1/n = 62	MD	‐1.00 [‐7.51 to 5.51]	0.76
Presence of nausea	1/n = 62	RR	0.39 [0.19 to 0.80]	0.01
Nausea intensity in PACU (VNRS)	1/n = 62	MD	‐0.70 [‐1.35 to ‐0.05]	0.03
Nausea intensity at 1 to 6 hours (VNRS)	1/n = 62	MD	‐1.70 [‐2.59 to ‐0.81]	0.0002
Nausea‐vomiting rate at 1 hour	1/n = 42	RR	23.00 [1.44 to 366.71]	0.03
Nausea‐vomiting rate at 3 hours	1/n = 42	RR	2.00 [0.20 to 20.41]	0.56
Adverse events: increase in IOP during maintenance of anaesthesia	1/n = 66	MD	‐3.90 [‐6.34 to ‐1.46]	0.002

CI: confidence interval; IOP: intraocular pressure; MD: mean difference; PACU: post‐anaesthesia care unit; RR: risk ratio; VAS: visual analogue scale; VNRS: verbal numerical rating scale.