The nurse is caring for a patient whose ventilator settings include 15 cm H2O of positive end- expiratory pressure (PEEP). The nurse understands that although beneficial, PEEP may result in:

A. While PEEP improves oxygenation by keeping alveoli open, it does not inherently improve cardiac output. Increased intrathoracic pressure from PEEP can actually reduce venous return, which may decrease preload and cardiac output, especially in hypovolemic patients. B. PEEP increases intrathoracic pressure, which can impede venous return to the right heart, reducing preload and ultimately decreasing cardiac output. Although PEEP improves oxygenation and prevents alveolar collapse, excessive PEEP can lead to hypotension and reduced organ perfusion. This is a key hemodynamic consideration in ventilated patients. C. Decreased venous return from PEEP would not cause fluid overload; it reduces preload and may contribute to hypotension. Fluid overload results from excessive fluid administration or impaired excretion, not PEEP-induced intrathoracic pressure. D. PEEP is actually used to prevent hypoxemia by keeping alveoli open during expiration. Excessive PEEP can cause barotrauma or decrease cardiac output, but it does not directly cause hypoxemia through its intended mechanism.