Sensitive assessment of ETCO₂ on circulatory function in critical ill patient - A narrative review

Unstable circulatory state is frequently found in critically ill patients, which could lead to adverse outcomes and prognosis. Circulatory function monitoring could reflect the circulatory status of patients and prompt clinicians to take timely intervention measures, which may improve the adverse outcomes of patients, signifying its prominence role during the process of diagnosis and treatment in critically ill patients. End-tidal carbon dioxide (ETCO2) monitoring has been included in the routine monitoring program during anesthesia by the American Society of Anesthesiologists since 1997, which has significant application value in anesthesia, intensive care unit, emergency department, pre-hospital first aid, and other aspects. ETCO2 could sensitively reflect the circulatory status of patients, and present values for early diagnosis and outcome prediction regarding to various types of shock and cardiac arrest. Besides, as a whistler, the role of ETCO2 in early warning has gradually become prominent. Therefore, this narrative review aimed to summarize the new perspective application of ETCO2 in circulatory assessment of critical ill patient, which is expected to draw attention by anesthetists with the value of evaluating circulatory function, in order to change or improve the prognosis and outcome of critically ill patients through timely intervention during perioperative period.