Physiologic Approach to Mechanical Ventilation in Right Ventricular Failure

During a mechanical breath, there is a progressive rise in PALV, PPL, and transpulmonary pressure (PALV2PPL) (Figure 2). Because the pulmonary arteries and veins are exposed to PPL, Pa and Pv also increase. Owing to the rise in transpulmonary pressure, however, PALV increases more than Pa and Pv, so capillary transmural pressure falls. [...]a mechanical breath shifts capillaries from zones 3 and 2 to zones 2 and 1 and increases their resistance. Because PEEP increases lung volume and transpulmonary pressure throughout the respiratory cycle (Figure 2), it magnifies the hemodynamic effects of mechanical ventilation and causes a continuous, proportional elevation in PVR. Hemodynamic Effects of Increased RV Afterload The right and leftventricles are enclosed by the relatively noncompliant pericardium and share a common septum. [...]changes in the size of one ventricle can alter the size of the other, and this is referred to as ventricular interdependence.