Effects of Positive End-Expiratory Pressure (PEEP) on Intracranial Pressure

Patients with disease processes that elevate intracranial pressure frequently have concomitant arterial hypoxemia. This hypoxemia may be caused directly by a damaged central nervous system, or it may result indirectly from the same etiology as that which caused the damage to the central nervous system or from alterations brought about by the treatment of a damaged central nervous system. A right-to-left intrapulmonary shunt is the usual cause of hypoxemia; therefore, positive end-expiratory pressure or continuous positive airway pressure may be therapeutic. We reviewed the literature for data supporting and refuting the potential detrimental side-effects of expiratory positive pressure on intracranial pressure. On the basis of this review, we conclude that no firm statement regarding the application of expiratory positive pressure to patients with known or suspected increased intracranial pressure can be made, and that caution and careful monitoring should be employed.