Cardiac output monitoring: how to choose the optimal method for the individual patient

To review the different methods available for the assessment of cardiac output (CO) and describe their specific indications in intensive care and perioperative medicine.

In critically ill patients, persistent circulatory shock after initial resuscitation is an indication for the assessment of CO to monitor the response to fluids and vasoactive agents. In patients with circulatory shock associated with right ventricular dysfunction, pulmonary artery hypertension, or acute respiratory distress syndrome, invasive CO monitoring using indicator dilution methods is indicated. Calibrated and uncalibrated pulse wave analysis enable absolute or relative CO changes to be monitored in real-time during the assessment of fluid responsiveness. In patients undergoing open-heart and thoracic aortic surgery, transesophageal echocardiography is recommended. In selected cardiac surgery patients, advanced hemodynamic monitoring using thermodilution methods can be considered. In high-risk noncardiac surgical patients, invasive pulse wave analysis or esophageal Doppler should be used for perioperative hemodynamic management.

Various invasive, minimally invasive, and noninvasive methods to assess CO are available. A profound understanding of the different CO monitoring methods is key to define indications for CO monitoring in the individual critically ill or surgical patient.