ABSTRACT
Noninvasive monitoring of end-tidal carbon dioxide (ETCO2) is not new technology but its routine use in the emergency department is a recent development. It is a better tool to evaluate ventilation when compared to oximetry because it provides the caregiver with breath-to-breath information. End-tidal carbon dioxide reflects the production, transportation, and elimination of CO2. This technology has been used to evaluate endotracheal tube placement. Now with both side stream and mainstream monitoring available, emergency departments can use ETCO2 in a variety of situations. The emergency nurse needs to be able to evaluate the configuration of the waveform in addition to the numeric value.