What is the primary function of CPAP in respiratory support?

The primary function of CPAP (Continuous Positive Airway Pressure) in respiratory support is to apply constant pressure to a spontaneously breathing patient. This technique helps keep the airways open, preventing them from collapsing during expiration, which is particularly beneficial for conditions like obstructive sleep apnea and certain forms of respiratory failure. By maintaining a steady level of pressure throughout the respiratory cycle, CPAP improves oxygenation and ventilation without requiring the patient to be fully mechanically ventilated.

In contrast, other options involve functions that are not characteristic of CPAP. Providing volume change during ventilation is more associated with modes of mechanical ventilation where tidal volumes are delivered, which is not a function of CPAP. Increasing respiratory rate and depth is not a primary feature of CPAP, as it supports spontaneous breathing rather than controlling the ventilation rate. Lastly, while CPAP does support breathing, it does not completely replace the need for artificial ventilation in cases where higher levels of respiratory assistance are required, such as in severe respiratory distress or failure. Therefore, focusing on the continuous application of pressure aligns directly with the defining capabilities of CPAP in respiratory management.