positive end-expiratory pressure (PEEP), positive airway pressure applied at the end of the exhalation phase during mechanical ventilation. Each successive breath begins from a new baseline. Air is delivered in cycles of constant pressure through the respiratory cycle. The patient is usually but not always intubated, and a ventilator cycles the air through an endotracheal tube. PEEP is used for the relief of respiratory distress secondary to prematurity, pancreatitis, shock, pulmonary edema, trauma, surgery, or other conditions in which spontaneous respiratory efforts are inadequate and arterial levels of oxygen are deficient. Close observation is necessary during PEEP therapy because excessive PEEP may decrease venous return to the heart. Blood gases and vital signs are monitored closely. If PEEP does not significantly improve the patient’s condition, its level is increased or it may be discontinued. Compare continuous positive airway pressure.
