Volume status: Monitoring

Central Venous Pressure: Not reliable, needs to be considered in clinical context. No direct correlation with RV end-diastolic volume index or stroke volume index.

Pulmonary Artery Occlusion Pressure: Not reliable, may not be helpful in guiding fluid therapy.

Transesophageal Echocardiography: assess for ventricular filling. Reliable, but requires equipment and extertise.

Arterial Pulse Pressure Variation (PPV): Dynamic measurement that assess the effect of intrathoracic pressure changes on stroke volume changes during mechanical ventilation. Useful in the setting of a preload dependent Right Ventricle, which in turn influences LV preload and stroke volume. If RV dependent, positive pressure ventilation will significantly decrease venous return and subsequently stroke volume. Arterial pulse pressure serves to represent stroke volume and studies have shown it to be a highly predictable measure of fluid status.