What is a major physiological outcome of using pressure support ventilation?

Using pressure support ventilation primarily aims to reduce the work of breathing for patients, particularly those with respiratory muscle weakness or fatigue. By providing a preset level of pressure during inhalation, the ventilator assists the patient's effort to take in breaths more easily. This alleviation of the demand on the respiratory muscles is fundamental in preventing or reversing muscle fatigue, which can be critical in patients recovering from respiratory distress or diseases.

As for the other options, they highlight aspects that do not align with the intended benefits of pressure support. For instance, while airway obstruction can occur for various reasons, it is not a direct physiological outcome of pressure support ventilation; in fact, it often serves to assist patients at risk of obstruction. Similarly, pressure support doesn't remove the need for ventilatory support entirely, as it is specifically designed to assist ongoing respirations rather than eliminate them. Lastly, while pressure supports overall ventilation, it does not inherently lead to higher airway pressures long-term; rather, it stabilizes pressures within a safe range to facilitate better gas exchange.