What does the EPAP represent in BiPAP?

The EPAP, or Expiratory Positive Airway Pressure, in BiPAP (Bilevel Positive Airway Pressure) specifically represents the pressure required to keep the airway open during expiration. This pressure acts as a baseline that helps to prevent airway collapse, especially in patients with conditions like obstructive sleep apnea or other respiratory issues. By maintaining this pressure, EPAP ensures that the airways remain patent and that no obstruction occurs during exhalation, thus improving ventilation and oxygenation.

This distinction is crucial in understanding the therapeutic role of BiPAP in managing respiratory failure or other conditions requiring support. The mechanism of EPAP contributes to overall effectiveness by facilitating better airflow and assisting in the reduction of work of breathing. It essentially counters the natural tendency for the upper airway to collapse, ensuring that patients can breathe more freely during both inhalation and exhalation.