Which of the following best describes positive pressure ventilation?

Positive pressure ventilation refers to a method of assisting or controlling breathing where air is actively forced into the lungs. This technique is commonly used in various medical scenarios, such as in patients who are unable to breathe on their own or in emergency situations requiring ventilation support.

When using positive pressure ventilation, devices such as bag-valve masks, ventilators, or CPAP machines are employed to deliver air by creating a pressure difference that moves air into the lungs. This is particularly effective in situations where the patient’s lungs may not be expanding adequately due to conditions such as respiratory failure or obstruction.

In contrast, the other descriptions do not align with the principles of positive pressure ventilation. Drawing air out of the lungs refers to negative pressure ventilation, where a vacuum effect promotes inhalation, whereas passive exchange is a characteristic of normal physiological breathing without external device assistance. The notion that air enters only through nasal passages simplifies the complex process of respiration, which involves both the upper and lower airways regardless of ventilation type.