Positive airway pressure therapy for heart failure

Figure 4 Bi-level positive airway pressure. Bi-level PAP provides two fixed levels of PAP, a higher level of pressure during inspiration (i.e., IPAP) and a lower level of pressure during expiration (i.e., EPAP), and thus provides pressure support during inspiration. EPAP: Expiratory positive airway pressure; IPAP: Inspiratory positive airway pressure; PAP: Positive airway pressure.