Volumetric and End-Tidal Capnography for the Detection of Cardiac Output Changes in Mechanically Ventilated Patients Early after Open Heart Surgery.

VtCO and EtCO reflected reductions in cardiac output, although correlations were modest. The changes in VtCO were larger than the changes in EtCO, but only EtCO detected CO reduction as judged by receiver operating characteristic curves. The predictive ability of EtCO in this setting was fair. This trial is registered with NCT02070861.