End-tidal carbon dioxide as a noninvasive monitor of circulatory status during cardiopulmonary resuscitation: a preliminary clinical study.

In four postoperative cardiac patients during controlled ventilation, acute circulatory failure was associated with decreases in end-tidal CO2 (PetCO2) and cardiac index. Closed cardiac compression caused an increase in both PetCO2 and cardiac index, with complete restoration to baseline values after successful CPR. Our data indicate that PetCO2 measurements during controlled ventilation in acute circulatory failure patients may be used as an indirect noninvasive tool to monitor the patient's hemodynamic status during CPR.