Table 3. Summary of findings compiled using GRADE methodology.

Outcome	No. of studies	Study design	Risk of bias	Inconsistency	Indirectness	Imprecision	Publication bias	Effect size	Certainty	Importance
								(95% CI)
Incidence of hypoxemic events (SpO2 < 90%)	4	RCT	Seriousa	Not serious	Not serious	Not serious	Undetected	RR: 0.25	⨁⨁⨁◯	Critical
								(0.14−0.42)	Moderate
Incidence of interrupted bronchoscopy due to desaturation	2	RCT	Seriousa	Not serious	Not serious	Seriousb	Undetected	RR: 0.19	⨁⨁◯◯	Important
								(0.02−1.86)	Low
Lowest SpO2 during bronchoscopy	4	RCT	Seriousa	Not serious	Not serious	Not serious	Undetected	WMD: 7.12	⨁⨁⨁◯	Important
								(5.39–8.84)	Moderate
PaO2 at the end of bronchoscopy	2	RCT	Seriousa	Not serious	Not serious	Seriousb	Undetected	WMD: 20.36	⨁⨁◯◯	Important
								(0.30–40.42)	Low
PaCO2 at the end of bronchoscopy	2	RCT	Seriousa	Not serious	Not serious	Seriousb	Undetected	WMD: −0.02	⨁⨁◯◯	Important
								(−2.31–2.27)	Low
EtCO2 at the end of bronchoscopy	2	RCT	Seriousa	Not serious	Not serious	Seriousb	Undetected	WMD: −0.12	⨁⨁◯◯	Important
								(−4.19–3.94)	Low

Abbreviations: CI, confidence interval; GRADE, quality of evidence grade; NI, no information; RCT, randomized controlled trial; RR, risk ratio; WMD, weighted mean difference; ⨁⨁⨁◯, moderate certainty; ⨁⨁◯◯, low certainty.

^aData reported as downgraded because of some concerns of bias.

^bData reported as downgraded because of wide CI or insufficient studies.