Interim analysis of the present study showed a significant decrease in mortality rate (p= 0.04) as well as in the number of days at the ICU p=0.0002.

The purpose of this study is to determine whether the noninvasive ventilation is more effective in the treatment of severe comunity acquired pneumonia in comparison with the conventional mechanical ventilation with orotracheal intubation.

Inclusion Criteria:

The criteria for the diagnosis of SCAP included:

• Blood systolic pressure lower than 90 mmHg or blood diastolic pressure lower than 60 mmHg
• RR higher than 30 breaths per minute
• PaO2/FiO2 lower than 250 while breathing through a Venturi mask with a 50% inspired oxygen fraction (FiO2)
• Bilateral or multiple lobar infiltrations evidenced by thorax X-ray, and
• Use of vasopressor drugs

Exclusion Criteria:

Exclusion criteria included:

• COPD
• Asthma
• Acute cardiogenic pulmonary edema
• Severe haemodynamic instability (arterial systolic pressure lower than 70 mmHg) or requirements of vasoactive drugs
• Glasgow score equal to or lower than 9 or requiring OTI for airway protection or for recent pulmonary resucitation
• Antecedents of respiratory failure resulting from neuromuscular pathology
• Failure of two or more organs
• Facial deformities; and
• Recent facial, aesophagic and gastric surgeries