the study compares two non-invasive respiratory support modalities ie CPAP and High Flow nasal cannula oxygen for the treatment of severe hypoxemic respiratory failure attributed to Community acquired Pneumonia.

CPAP and High Flow nasal cannula oxygen are two established modalities for non-invasive respiratory support . In COVID pandemic era both CPAP and HFNO were widely used in the ward for the treatment of COVID-19 induced acute hypoxemic respiratory failure in order to prevent progression to intubation. Head to head comparison between the two modalities mentioned for the treatment of severe hypoxemic respiratory failure is not available neither in COVID pneumonia or Community acquired pneumonia (CAP).

Inclusion Criteria:

• Adult patients with age >18 year old.
• Been hospitalized with community acquired pneumonia
• hospitalized in common ward (not ICU)
• Patients should have pneumonia- pulmonary infiltrates in chest-xray and hypoxemic respiratory failure.
• Patients should be unable to keep: SpO2>93% with FiO2 50%, or SpO2 95% with FiO2 50% and have evidence of respiratory distress defined as Respiratory rate -RR>35/min

Exclusion Criteria:

• Need for immediate or imminent intubation
• not fit for escalation of treatment: defined as intubation, mechanical ventilation and ICU support.
• Pregnant women
• Contraindication to CPAP or HFNO

Adult Patients with community acquired pneumonia induced acute hypoxemic respiratory failure that are hospitalized in the common ward and need FiO2 >50% to keep SpO2 >93%, or SpO2 >95% in case of persistent respiratory distress defined as RR>35/min.