Clinical Applications of Respiratory Modeling via Quantitative Capnography

Abstract

Time-based capnography measures the partial pressure of carbon dioxide in exhaled air as a function of time. It is the standard of care in a variety of patient settings in the United States and Canada, including emergency care, perioperative care, and even in ambulance settings. In current clinical practice, the resultant waveform signal, or capnogram, is used merely to establish the presence of respiration or to determine the respiratory rate or end-tidal CO2 concentration. However, the capnogram shape also has diagnostic value, but is only assessed qualitatively, by visual inspection. Here, we review mechanistic and data-driven model-based approaches to quantitative analysis of the capnogram to aid diagnosis and screening in a variety of patient conditions.