Comparison 1. Capnography plus standard monitoring versus standard monitoring only.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Oxygen desaturation	3	1272	Risk Ratio (M‐H, Random, 95% CI)	0.89 [0.48, 1.63]
2 Hypotension	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
3 Emesis, pulmonary aspiration	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
4 Airway interventions	3	1272	Risk Ratio (M‐H, Random, 95% CI)	1.26 [0.94, 1.69]
5 Oxygen desaturation (subgroup analysis)	3		Risk Ratio (M‐H, Random, 95% CI)	Subtotals only
5.1 Adults (aged ≥ 18 years)	2	1118	Risk Ratio (M‐H, Random, 95% CI)	0.79 [0.37, 1.71]
5.2 Paediatric (aged <18 years)	1	154	Risk Ratio (M‐H, Random, 95% CI)	1.33 [0.49, 3.66]
6 Oxygen desaturation (sensitivity analysis), Deitch 2010 excluded	2	1140	Risk Ratio (M‐H, Random, 95% CI)	1.33 [0.66, 2.69]
7 Airway interventions (subgroup analysis)	3	1272	Risk Ratio (M‐H, Random, 95% CI)	1.26 [0.94, 1.69]
7.1 Adults (aged ≥ 18 years)	2	1118	Risk Ratio (M‐H, Random, 95% CI)	1.44 [1.16, 1.79]
7.2 Paediatric (aged < 18 years)	1	154	Risk Ratio (M‐H, Random, 95% CI)	0.97 [0.71, 1.34]