Which characteristic accurately describes positive pressure ventilation?

Positive pressure ventilation is a mode of mechanical ventilation where air is delivered to the lungs under pressure. One of the defining features of this technique is that it generally necessitates an artificial airway, such as an endotracheal tube or a tracheostomy, to ensure that the air can effectively reach the patient's lungs. This artificial airway allows for the direct introduction of pressurized air, which is essential for maintaining adequate ventilation, especially in patients who have compromised respiratory function.

While it’s true that some forms of positive pressure ventilation can be applied non-invasively using masks (such as CPAP or BiPAP), the requirement for an artificial airway is most commonly associated with situations where higher levels of respiratory support are needed or when patients are unable to breathe adequately on their own. Thus, this characteristic remains a fundamental aspect of the use of positive pressure ventilation in various clinical settings.

In contrast, other options do not accurately describe positive pressure ventilation in this context. For instance, while positive pressure ventilation is indeed applied to the lungs, it operates within the body rather than outside it. Furthermore, it does not resemble physiologic ventilation, which relies on negative pressure to draw air into the lungs, such as in normal breathing. Lastly, while positive pressure devices