Time frames for the application of noninvasive positive-pressure ventilation in acute respiratory failure (ARF) according to the severity and end-of-life choices of patients. Time frames for the application of noninvasive positive-pressure ventilation in acute respiratory failure (ARF) according to the severity and end-of-life choices of patients. ETI: endotracheal intubation; IMV: invasive mechanical ventilation; NIV: noninvasive ventilation; EXT-F: extubation failure. Raffaele Scala, and Lara Pisani Eur Respir Rev 2018;27:180029 ©2018 by European Respiratory Society