Sequential application of oxygen therapy via high-flow nasal cannula and noninvasive ventilation in acute respiratory...

The aim of this study was to evaluate the clinical efficacy of humidified oxygen via high-flow nasal cannula (HFNC) alternating with noninvasive ventilation (NIV) in acute hypoxemic respiratory failure (AHRF).

We performed a prospective observational study in a 12-bed ICU of a university hospital. All subjects with a PaO2 /FIO2 of ≤300 mm Hg with standard mask oxygen and a breathing frequency of > 30 breaths/min or signs of respiratory distress were included and treated with HFNC first and then NIV. Ventilatory parameters, blood gases, and tolerance were recorded during 2 consecutive sessions of NIV and HFNC. Outcome was assessed after continuation of this noninvasive strategy.

Twenty-eight subjects with AHRF were studied, including 23 (82%) with ARDS. Compared with standard oxygen therapy, PaO2 significantly increased from 83 (68-97) mm Hg to 108 (83-140) mm Hg using HFNC and to 125 (97-200) mm Hg using NIV (P<.01), whereas breathing frequency significantly decreased. HFNC was significantly better tolerated than NIV, with a lower score on the visual analog scale. The non-intubated subjects received HFNC for 75 (27-127) h and NIV for 23 (8-31) h. Intubation was required in 10 of 28 subjects (36%), including 8 of 23 subjects with ARDS (35%). After HFNC initiation, a breathing frequency of ≥30 breaths/min was an early factor associated with intubation.

HFNC was better tolerated than NIV and allowed for significant improvement in oxygenation and tachypnea compared with standard oxygen therapy in subjects with AHRF, a large majority of whom had ARDS. Thus, HFNC may be used between NIV sessions to avoid marked impairment of oxygenation.