What type of ventilation requires two levels of CPAP and allows spontaneous breathing at both levels?

• A. Volume support ventilation
• B. Pressure regulated volume control
• C. Airway pressure-release ventilation
• D. Mandatory minute ventilation

Answer: (C)

Airway pressure-release ventilation (APRV) is a mode that utilizes two levels of continuous positive airway pressure (CPAP) and allows the patient to breathe spontaneously at both pressure levels. This mode enhances oxygenation by maintaining certain airway pressures while permitting natural breathing efforts from the patient, which can help in reducing the work of breathing and improving overall ventilation.

The dual CPAP levels in APRV facilitate better gas exchange, as they provide a means for patients to release trapped air and spontaneously inhale at a higher pressure, followed by a release phase at a lower pressure, enhancing lung recruitment and reducing shunting. This is particularly beneficial for patients with conditions like Acute Respiratory Distress Syndrome (ARDS), where lung compliance is often impaired, and maintaining appropriate pressure levels can significantly improve oxygenation.

In contrast, other modes listed have different mechanisms and objectives. Volume support ventilation typically assists with lung volumes but does not specifically employ dual levels of CPAP. Pressure regulated volume control is primarily focused on delivering breaths at a target volume while maintaining a specific pressure. Mandatory minute ventilation ensures a minimum minute ventilation but does not provide the unique two-level mechanism inherent to APRV. Understanding how APRV operates not only clarifies its individual functionalities but also emphasizes its advantages in managing patients requiring