What Are the Expected Benefits?

The use of NIV to prevent invasive mechanical ventilation is expected to be associated with a decrease in the occurrence of several complications generally attributed to invasive mechanical ventilation. This was shown regarding the risk of nosocomial pneumonia. In 2000, Girou et al. reported in a matched case-control study that the use of NIV was associated with lower rate of ventilator-acquired pneumonia and a reduced ICU mortality as compared to conventional mechanical ventilation [24]. Randomized controlled trials showed reduced mortality with NIV in highly selected populations presenting acute hypoxemic respiratory failure such as patients with immunosuppression [25, 26]. Others have reported similar benefit in non- immunocompromised patients either in very selected population [27] or in heterogeneous groups [28-30]. Hence, it appears that NIV could be beneficial in some patients, but the overall evidence is not entirely consistent. The use of NIV in ARDS is, however, also associated with two potential risks: delaying the time for intubation and possibly favoring lung injury with relative hyperventilation.