The Double-Trunk Mask Improves Oxygenation During High-Flow Nasal Cannula Therapy for Acute Hypoxemic Respiratory Failure.

BACKGROUND: High-flow nasal cannula (HFNC) oxygen therapy is used to deliver an F-IO2 from 0.21 to 1.0. The double-trunk mask (DTM) is a device designed to increase the F-IO2, in patients with a high inspiratory flow demand. The aim of our study was to evaluate the effect of DTM in hypoxemic subjects already receiving HFNC. METHODS: We report a prospective multi-center crossover pilot study including 15 subjects treated with HFNC for acute hypoxemic respiratory failure. Measurements were performed at the end of 30-min periods with HFNC only, with HFNC + DTM, and again with HFNC only. RESULTS: Compared with HFNC alone, HFNC + DTM increased P-aO2 from 68 +/- 14 mm Hg to 85 +/- 22 mm Hg (P < .001) and did not affect P-aO2 (P = .18). In the 11 responders, the P-aO2 increased from 63 +/- 12 mm Hg to 88 +/- 23 mm Hg (P < .001). No complications were reported during DTM use. CONCLUSION: In subjects receiving oxygen via HFNC, the addition of the DTM over the HFNC increased P-aO2 without changing the P-aO2.