The objective of the study is to determine whether adjunctive mask of our design (Double Trunk Mask - DTM) has an effect on increasing arterial pressure in Oxygen (PaO2) diagnosed with severe hypoxia.

This is a single-center, randomized, blind investigator, 2-way crossover study design. Enrolled participants had hypoxia being treated at Intensive Care Unit associated with a hospital in Hornu (Epicura).

The study consisted of two intervention periods separated by a washout period of 30 minutes.

The objective of the study is to determine whether adjunctive mask of our design (Double Trunk Mask - DTM) has an effect on increasing arterial pressure in Oxygen (PaO2) diagnosed with hypoxia.

The protocol and informed consent documents were reviewed and approved by a recognized ethics review board at the study facility. The study was performed in accordance with the Declaration of Helsinki.

Inclusion Criteria:

• Regardless of gender, at least 18 years of age and diagnosed with Hypoxia (PaO2/FiO2 < 380 mm Hg), dyspnea, respiratory rate (RR) ≥ 25 CPM, PaCO2 ≤ 45 mmHg, patient with an arterial catheter and without hemodynamic instability, Glasgow Coma Scale ≥ 12/15, written consent. Participants were also required to have a sufficient level of education to understand study procedures and be able to communicate with site personnel.

Exclusion Criteria:

• Patients were excluded if they Hypercapnia (> 45 mm Hg with respiratory acidosis), COPD, pulmonary fibrosis, hypoventilation obesity syndrome, arterial pressure < 60 mm Hg or treatment by epinephrine > to 0,1 gamma/kg/minute, deterioration of awareness (Glasgow scale < or = 12), acute confusional state.

Participants were randomized in a 1:1 ratio to receive either classical oxygenation with nasal cannula (NC) for 20 minutes or NC with an adjunctive of a Double Trunk Mask.