How does a CPAP machine function to assist patients?

A CPAP (Continuous Positive Airway Pressure) machine functions primarily by maintaining a constant positive pressure in the airways throughout the breathing cycle, which helps to keep the alveoli open. This is essential for patients, particularly those with obstructive sleep apnea, as it prevents the airways from collapsing during sleep, thereby improving oxygenation and reducing the risk of apneas.

When the CPAP machine delivers this positive pressure, it not only keeps the upper airway and alveoli open but also helps to facilitate gas exchange, ensuring more effective ventilation. This mechanism improves oxygen delivery to the bloodstream and reduces the work of breathing, promoting better overall respiratory function.

In contrast, options referring to the machine's function in a different manner, such as increasing air pressure only during exhalation or providing oxygen only during specific hours, do not accurately describe how CPAP operates. The focus of a CPAP machine is on maintaining airway patency continuously rather than merely when a patient exhales or during sleep hours.