What potential issue can increased PEEP cause?

Increased Positive End-Expiratory Pressure (PEEP) can lead to decreased preload and hypotension, making this choice the most accurate. The mechanism behind this is related to the effects of elevated intrathoracic pressure caused by the PEEP during mechanical ventilation. As the PEEP raises the end-expiratory lung volume, it can compress the thoracic structures, resulting in reduced venous return to the heart.

In particular, the increase in intrathoracic pressure can diminish the pressure gradient that facilitates blood flow back to the right atrium, consequently leading to decreased preload. As preload falls, this can reduce cardiac output and potentially result in hypotension because the amount of blood entering the heart, and thus available for circulation, is diminished.

Understanding this dynamic is crucial in anesthetic management, especially in patients with compromised cardiovascular function, where the maintenance of appropriate preload and blood pressure is vital.