Certified Medical-Surgical Registered Nurse Practice Exam 2025 - Free Practice Questions and Study Guide

In the context of mechanically ventilated patients, the application of Positive End-Expiratory Pressure (PEEP) is primarily aimed at improving oxygenation by preventing the collapse of alveoli at the end of expiration. However, a side effect that can commonly occur with the use of PEEP is decreased cardiac output.

When PEEP is applied, it increases intrathoracic pressure. This increase in pressure can reduce venous return to the heart, leading to a decrease in preload. A diminished preload can subsequently affect stroke volume and cardiac output. In patients with pre-existing cardiac problems or those who are hypovolemic, the impact of PEEP on cardiac output can be more pronounced. This relationship highlights the delicate balance in managing ventilatory support and hemodynamic status in critically ill patients. Understanding this effect is crucial for nurses, as it can inform decisions regarding fluid management and medications to support cardiac output during mechanical ventilation.