Utility of changes in end-tidal carbon dioxide after volume expansion to assess fluid responsiveness in the operating room: a prospective observational study.

Background: From a physiological viewpoint, changes in end-tidal carbon dioxide (EtCO) could be a simple, noninvasive, and inexpensive way to monitor changes in cardiac index. This study aimed to assess the utility of changes in EtCO as a marker of fluid responsiveness after volume expansion in the operating room.

Methods: A prospective observational study was conducted in a tertiary university teaching hospital, from August 2018 to February 2019.