The purpose of the study is to compare the efficacy of alternating Non Invasive Ventilation NIV and High Flow Oxygen HFO compared to High Flow Oxygen HFO alone on gas exchanges and prognosis in pneumonia-associated acute hypoxemic respiratory failure

Both Non Invasive Ventilation (NIV) and High Flow Oxygen through nasal cannula (HFO) are widely used in the setting of hypoxemic respiratory failure of heterogeneous etiology, with no definitive evidence for the superiority of one technique on the other. The purpose of this study is to determine whether alternating NIV and HFO brings any advantage on gas exchanges and prognosis compared to the use of HFO alone in the homogeneous setting of pneumonia-associated acute hypoxemic respiratory failure

Inclusion Criteria:

• Diagnosis of pneumonia based on at least two clinical/laboratory criteria and 1 radiologic criterion among the following:

  • Clinical criteria: fever, cough, purulent sputum, pulmonary examination positive for signs consistent with pneumonia
  • Laboratory criteria: leukocytosis (White blood cells >10000/mcL) or leukopenia (White blood cells < 4000/mcL), rise of the inflammatory markers
  • Radiologic criteria: consolidations at Chest X-ray or CT scan

• Hypoxemic respiratory failure, based on all the following criteria

  • PaO2/FiO2 < 300 after at least 15 minutes conventional oxygen therapy with a FiO2 ≥ 50%
  • Respiratory Rate (RR) ≥ 25/min or need for use of accessory muscles

• Informed consent to study participation

Exclusion Criteria:

• Age < 18 years
• Hypercapnic respiratory failure (pCO2 > 60 mmHg at presentation) such as in Chronic Obstructive Pulmonary Disease
• Presence of another cause of hypoxemic respiratory failure - e.g. pulmonary embolism, acute respiratory distress syndrome (ARDS), pulmonary oedema
• Hemodynamic instability with necessity for use of inotropes and/or vasopressors
• Indication for endotracheal intubation (ETI): Glasgow Coma Scale (GCS) <8, agitation, device intolerance, respiratory arrest
• Immunosuppression (chronic immunosuppressive therapy, clinical history positive for any immunodeficiency - congenital or acquired)
• Do Not Resuscitate (DNR) and Do Not Intubate (DNI) indication
• Tracheostomy
• Nocturnal CPAP ventilation therapy
• Any other condition which the clinician would considered an adjunctive risk for taking part in the study or that would not permit the participant to complete it