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; Absence ofhistory of chronic respiratory failure or moderate to severe cardiac insufficiency (NYHA>2 or left ventricular ejection fraction<50%); Informed consent Patients that have already received NIV, CPAP continuously for more than 24 hours beforethe 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 clinically diagnosedShock requiring administration of vasoactive agents (norepinephrine>0.1 mcg/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.