Capnograph is an indispensable tool for monitoring metabolic and respiratory function. In this study, the aim was to review the applications of end-tidal carbon dioxide (ETCO2) monitoring in emergency department, multiple databases were comprehensively searched with combination of following keywords: “ETCO2”, “emergency department monitoring”, and “critical monitoring” in PubMed, Google Scholar, Scopus, Index Copernicus, EBSCO and Cochrane Database
