During noninvasive continuous positive airway pressure (CPAP) the patient's respiratory system is maintained throughout the whole respiratory cycle at a constant pressure higher than the atmospheric pressure, usually termed the positive end-expiratory pressure (PEEP). Noninvasive CPAP is void of any active support for the patient's work of breathing and therefore cannot be considered a form of ventilation. \uc2\ua9 2010 Springer-Verlag Berlin Heidelberg
