Noninvasive positive pressure ventilation for patients with acute hypoxemic respiratory failure?

The re-emergence of noninvasive positive pressure ventilation (NIV) represents perhaps the single greatest advance in mechanical ventilation over the last 20 years. Clear benefit has been demonstrated for patients with respiratory failure in the setting of acute exacerbations of chronic obstructive pulmonary disease and cardiogenic pulmonary edema. While there are advocates for the use of NIV in patients presenting with acute hypoxemic respiratory failure not due to cardiogenic pulmonary edema, benefit for these patients is less clear. This article reviews briefly the heterogeneity of hypoxemic respiratory failure and looks at the current evidence to support NIV in this setting in some depth. Presently, there is little evidence to support the use of NIV for patients presenting with hypoxemic respiratory failure who fulfill the American and European Consensus Conference definition of acute lung injury or acute respiratory distress syndrome, other than in patients with high risk for death if endotracheally intubated (immunocompromised patients, postlung resection acute respiratory distress syndrome). As there are reasonable rationales for both benefit and harm, there is a need for a large, multicenter, randomized, controlled trial to clarify whether NIV offers benefit in terms of a reduced need for endotracheal intubation, length of stay and hospital mortality.