on-invasive ventilation (NIV) is the delivery of oxygen (ventilation support) via a face mask and therefore eliminating the need of an endotracheal airway.[1] NIV achieves comparative physiological benefits to conventional mechanical ventilation by reducing the work of breathing and improving gas exchange.[2]
The intervention is recognised as an effective treatment for respiratory failure in chronic obstructive pulmonary disease, cardiogenic pulmonary oedema and other respiratory conditions without complications such as respiratory muscle weakness, upper airway trauma, ventilator-associated pneumonia, and sinusitis.[13]
NIV works by creating a positive airway pressure - the pressure outside the lungs being greater than the pressure inside of the lungs. This causes air to be forced into the lungs (down the pressure gradient), lessening the respiratory effort and reducing the work of breathing[4]. It also helps to keep the chest and lungs expanded by increasing the functional residual capacity (the amount of air remaining in the lungs after expiration) after a normal (tidal) expiration; this is the air available in the alveoli available for gaseous exchange[5]. There are two types of NIV non-invasive positive-pressure (NIPPV) and Negative-Pressure Ventilation (NPV).