Venovenous (VV) ECMO is used in patients suffering from refractory hypoxemia or hypercapnia due to a range of pathology including but not limited to acute respiratory distress syndrome, pneumonitis, or status asthmaticus. Venoarterial (VA) ECMO can be used in patients suffering from cardiogenic shock due to etiologies such as myocardial infarction, viral myocarditis, or postcardiotomy shock.

Less-invasive monitors, such as the Vigeleo, Flotrac, and esophageal cardiac output monitors, are not validated for ECMO patients and are unreliable in this population due to the presence of arrhythmia, right ventricular dysfunction, false elevations or reductions in central venous pressure, minimized ventilator settings, and the assumption that blood flow is out of the heart instead of concomitantly toward it.

The physiology of ECMO is complex and makes routine measurements of right atrial (or central venous) pressures, pulmonary artery pressures, pulmonary capillary wedge pressures, and cardiac output context-dependent and complex. A thoughtful approach is important to avoid misinterpretation of important physiologic parameters, which can result in incorrect management decisions. What follows is a brief description of considerations for invasive cardiovascular monitoring in patients on VV and VA ECMO, with special considerations for various cannula configurations.