Positive end-expiratory pressure will increase intrathoracic pressure, leading to:
- decreased venous return
- increased RV afterload
- decreased ventricular compliance
- decreased ventricular contractility
PEEP will decrease cardiac output in hypovolemic and normovolemic patients because of the drop in venous return.
If a patient has poor LVEF or CHF, PEEP will reduce LV transmural pressure, reducing afterload, which improves LV function. PAOP will also be reduced.