Noninvasive ventilation (NIV) is a ventilation modality that supports breathing by using mechanically assisted breaths without the need for intubation or a surgical airway. NIV is divided into two main types, negative-pressure ventilation (NPV) and noninvasive positive-pressure ventilation (NIPPV). NPV NPV periodically generates a negative (subatmospheric) pressure on the thorax wall, reflecting the natural breathing…
