Helmet NIV vs. CPAP vs. High-flow Nasal Oxygen in Hypoxemic Respiratory Failure

Inclusion Criteria:

• Acute symptoms of respiratory failure PaO2/FiO2 ratio ≤ 200; PaCO2≤45mmHg; Absenceof history of chronic respiratory failure or moderate to severe cardiacinsufficiency (NYHA>2 or left ventricular ejection fraction<50%); Informed consent

Patients that have already received NIV, CPAP continuously for more than 24 hours before the screening visit will be excluded.

Other Exclusion Criteria:

• Pregnancy;

• Exacerbation of asthma or chronic obstructive pulmonary disease;

• Hypercapnia (PaCO2>45 mmHg) with or without respiratory acidosis;

• More than 2 organ failures, including the lung.

• Documented pneumothorax;

• Clinical diagnosis of Cardiogenic pulmonary edema;

• Haemodynamic instability (Systolic blood pressure<90 mmHg or mean arterialpressure<65mmHg) and/or lactic acidosis (lactate>5 mmol/L) and/or clinicallydiagnosed Shock requiring administration of vasoactive agents (norepinephrine>0.1mcg/Kg/min);

• Metabolic Acidosis (pH <7.30 with normal- or hypo-carbia);

• Chronic kidney failure requiring dialysis before ICU admission;

• Chronic hypoxemic respiratory failure requiring long-term oxygen therapy;

• Altered neurological status that requires immediate intubation and/or making thepatient uncooperative;

• Urgent need for endotracheal intubation, according to the decision of the attendingphysician;

• Do not intubate order;

• Decision of withdrawal of life-sustaining therapy;

• Thoracic or abdominal surgery in the previous 7 days;

• Any condition that makes the patient very likely to require endotracheal intubationdue to a reason different from respiratory failure;

• Recent head surgery or anatomy that prevent the application of helmet or HFNC topatient's face.