The additional safety effect of capnography monitoring during non-advanced endoscopic procedures has not been adequately examined. We aimed to evaluate the effectiveness of capnography monitoring, alongside standard monitoring, in reducing sedation-related hypoxemia.

A systematic review across MEDLINE and Cochrane Central Register for all types of trials evaluating the efficacy of capnography monitoring in addition to standard monitoring in reducing the incidence of SRAE was conducted for studies published between 01.01.2019 and 31.07.2025. The primary outcome was the risk of sedation-related hypoxemia. The pooled results for the study outcomes were presented as Risk Ratios (RR) with the 95% confidence intervals (CIs). We also performed sensitivity analyses by the severity of oxygen desaturation (mild and severe), low and high-risk procedures, and type of sedation (propofol vs. non-propofol vs. mixed regimens). We assessed the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

Two RCTs, four service evaluation studies, and one cohort study were included. Compared to standard monitoring, addition of capnography significantly reduced the risk of oxygen desaturation [RR 0.61, 95% CI (0.46-0.82; I²=74%)], with this effect being significant both for RCTs [RR 0.57, 95% CI (0.35-0.93); I²=70%] and non-RCT studies [RR 0.64, 95% CI (0.43-0.96; I²=80%], respectively; there was very low confidence in estimates. Capnography use led to a significantly lower incidence of both mild and severe hypoxemia [RR 0.74, 95% CI (0.63-0.85); I2=61% and RR 0.54, 95% CI (0.40-0.73); I2=44%, respectively]. Notably, the positive impact of capnography was also significant for low and high-risk procedures in terms of mild [RR 0.75, 95% CI (0.60-0.93); I²=69% and RR 0.72, 95% CI (0.57-0.89); I²=55%, respectively] and severe oxygen desaturation [RR 0.75, 95% CI (0.60-0.93); I²=69% and RR 0.72, 95% CI (0.57-0.89); I²=54%, respectively]. In terms of sedation type, the use of capnography was associated with a reduced risk ratio of oxygen desaturation overall; however, statistical significance was only noted in studies analyzing propofol [RR 0.59, 95% CI 0.46-0.76; I²=54%].

Addition of capnography to standard monitoring decreased the incidence of both mild and severe hypoxemia during sedation for gastrointestinal procedures, regardless of procedural risk.