High-flow nasal cannula oxygen therapy for acute exacerbation of interstitial pneumonia: A case series.

We report 3 cases (all men, age: 69-81 years) of acute exacerbation of interstitial pneumonia (AEIP) that were successfully treated with a high-flow nasal cannula (HFNC), which delivers heated, humidified gas at a fraction of inspired oxygen (FIO2) up to 1.0 (100%). Oxygenation was insufficient under non-rebreathing face masks; however, the introduction of HFNC with an FIO2 of 0.7-1.0 (flow rate: 40 L/min) improved oxygenation and was well-tolerated until the partial pressure of oxygen in blood/FIO2 ratio increased (between 21 and 26 days). Thus, HFNC might be an effective and well-tolerated therapeutic addition to the management of AEIP.