Continuous positive airway pressure (CPAP) therapy works by reopening collapsed alveoli when the patient:

Continuous positive airway pressure (CPAP) therapy is a non-invasive ventilatory support method used primarily to treat conditions such as obstructive sleep apnea and certain types of respiratory distress. The key concept behind CPAP is maintaining a constant pressure in the airways, which helps keep the alveoli open during both inhalation and exhalation.

When a patient exhales against the positive pressure provided by CPAP, it helps to keep the airways open and prevents the collapse of smaller airways and alveoli. This is crucial because during exhalation, there is a risk that smaller airways can collapse if the pressure drops too low. By maintaining a positive pressure, CPAP effectively prevents these collapses, allowing for better gas exchange and improved oxygenation.

Moreover, the other options presented focus on conditions that do not directly facilitate the reopening of collapsed alveoli in the way that exhaling against continuous positive pressure does. While inhaling deeply could open the alveoli, the maintenance of pressure during exhalation is vital to prevent their collapse again. The mention of supplemental oxygen refers to a treatment that enhances oxygen content in the blood but does not inherently keep the alveoli open. Lastly, a supine position may assist in some scenarios by improving lung mechanics