Definition of PEEP

PEEP: Abbreviation for positive end-expiratory pressure. A method of ventilation in which airway pressure is maintained above atmospheric pressure at the end of exhalation by means of a mechanical impedance, usually a valve, within the circuit. The purpose of PEEP is to increase the volume of gas remaining in the lungs at the end of expiration in order to decrease the shunting of blood through the lungs and improve gas exchange. PEEP is done in ARDS (acute respiratory failure syndrome) to allow reduction in the level of oxygen being given.