What does the "positive pressure" in NPPV imply about the breathing pattern during use?

The use of "positive pressure" in noninvasive positive pressure ventilation (NPPV) primarily refers to the fact that the pressure delivered during inhalation is higher than during exhalation. This difference in pressure facilitates the movement of air into the lungs, thereby aiding in ventilation.

When initiating inhalation, the higher pressure helps to overcome the resistance of the airways and allows for a greater volume of air to enter the lungs. During exhalation, the pressure decreases, which allows for passive expiration of air out of the lungs. This gradient between inhalation and exhalation pressures is crucial for maintaining effective ventilation and optimizing gas exchange in patients who may be facing respiratory difficulties.

The correct understanding of this pressure difference is essential for effective use of NPPV, as it helps clinicians tailor support to the individual needs of each patient, improving overall respiratory mechanics and comfort.