Mechanical Ventilation Test 3 Practice 2026 – Complete Exam Prep

High PEEP raises intrathoracic pressure, which compresses the heart and great veins. This reduces venous return to the right heart, lowering preload and, in turn, stroke volume and cardiac output. The result can be hypotension and overall hemodynamic instability. PEEP helps keep alveoli open and improve oxygenation, but when it’s too high, the dominant effect shifts to decreased preload rather than improved cardiac performance. So the typical consequence is decreased venous return and potential hemodynamic compromise.