A Comparison of the End-tidal CO2 Measured by Portable Capnometer and the Arterial PCO2 in Spontaneously Breathing Patients

An end-tidal CO2 (ETCO2) monitor (capnometer) is used most often as a noninvasive substitute for PaCO2 in anesthesia, anesthetic recovery and intensive care. However, the utility and accuracy of the portable capnometer in spontaneously breathing patients with or without chronic pulmonary diseases has received little recognition.