The Effectiveness of Capnography Versus Pulse Oximetry in Detecting Respiratory Adverse Events in the Postanesthesia Care Unit (PACU): A Narrative Review and Synthesis

Purpose: The objective of this review was to evaluate the effectiveness of capnography monitoring versus standard monitoring of pulse oximetry in detecting respiratory adverse events in nonintubated pediatric and adult postanesthesia care unit (PACU) patients.

Design: Experimental, quasi-experimental, and observational studies examining pulse oximetry and capnography in adult and pediatric patients in the PACU were included in this systematic review.

Methods: An initial search of MEDLINE and CINAHL, PubMed, Web of Science, Prospero, Google Scholar, and Cochrane was undertaken to identify articles on the topic. The text words contained in the titles and abstracts of relevant articles, and the index terms used to describe the articles were used to develop a full search strategy in July 2019. Reference lists of studies included at critical appraisal stage were hand-searched. Studies published in English from 1978 onward were included.

Findings: Meta-analysis was not possible due to variation in outcome measurements; therefore, results are presented in narrative form. Four studies were included in the review: 1 randomized controlled trial (RCT) and 3 observational cross-sectional studies. The RCT was considered of moderate to high quality, and the observational cross-sectional studies were of high quality. The main findings of this review suggest that there is limited high-quality evidence that capnography improves detection of respiratory adverse events in the PACU versus pulse oximetry.

Conclusions: The lack of RCTs and varied outcomes measures in the 4 studies reviewed meant that meta-analysis was not possible. Early detection of respiratory adverse events afforded by the addition of PETCO₂ to SpO₂ in the PACU was seen in these studies. More research is needed to determine if widespread implementation of capnography in addition to pulse oximetry would reduce severity of respiratory related adverse events in the PACU through more timely identification.