Impact of Microstream capnography monitoring on adverse events during procedural sedation: retrospective analysis of a quality improvement initiative performed in five centres

OBJECTIVES: To quantify the safety impact of using Microstream capnography monitoring during procedural sedation for gastrointestinal procedures and bronchoscopy and to identify a risk-stratification method. METHODS: A quality improvement initiative at hospitals in Belgium, Canada, Spain, Turkey, and the UK included 6734 procedures in adults undergoing procedural sedation, who received either Microstream capnography monitoring added to standard monitoring, or standard monitoring only. The primary outcome was the incidence of any intraoperative adverse event. Incidence of any severe adverse event was assessed separately. American Society of Anesthesiologists classification, sedatives, procedure time, and procedure type were used to adjust odds ratios (OR) derived from logistic regressions for adverse events and applied in risk stratification. RESULTS: Adverse event incidence decreased from 10.8% standard monitoring to 6.7% using capnography, with a number needed to treat (NNT) of 24. The adjusted ORs were 0.54 (95% confidence interval (CI): 0.44-0.66, P < 0.001) for any adverse event and 0.46 (95% CI: 0.26-0.83, P = 0.01) for any severe adverse event. Procedures were stratified into low- (N = 1292, 25.6%), medium- (N = 2383, 47.2%), and high-risk (N = 1376, 27.2%) groups. Capnography monitoring significantly decreased adverse events in all risk groups with absolute risk reductions (NNT) of 3.8% (26), 4.6% (22), and 6.7% (15) for low- to high-risk groups, respectively. Severe adverse events significantly decreased with capnography in the high-risk group only (3.5% vs. 0.9%; OR 0.25, 95% CI: 0.10-0.60; NNT = 38). The risk stratification model should be considered exploratory and requires further validation. CONCLUSION: Capnography in procedural sedation significantly reduced both any and severe adverse events and should benefit patients in routine practice. We recommend considering American Society of Anesthesiologists level, sedation type, and planned procedure time in future risk stratification evaluations.