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 FIO2 from 0.21 to 1.0. The double-trunk mask (DTM) is a device designed to increase the FIO2 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 PaO2 from 68 ± 14 mm Hg to 85 ± 22 mm Hg (P < .001) and did not affect PaCO2 (P = .18). In the 11 responders, the PaO2 increased from 63 ± 12 mm Hg to 88 ± 23 mm Hg (P < .001). No complications were reported during DTM use.

Conclusions: In subjects receiving oxygen via HFNC, the addition of the DTM over the HFNC increased PaO2 without changing the PaCO2 .