ARDS	Acute respiratory distress syndrome
ATS	American thoracic society
CAP	Community acquired pneumonia
CI	Confidence interval
COPD	Chronic obstructive pulmonary disease
CPAP	Continuous positive airway pressure
CT	Computed tomography
ETI	Endotracheal intubation
HR	Hazard ratios
ICU	Intensive care unit
IDSA	Infectious Diseases Society of America
MDR	Multidrug-resistant pathogens
PEEP	Positive end-expiratory pressure
Q1	First quartile
Q3	Third quartile
SAPS	Simplified acute physiology score
SOFA	Sequential organ failure assessment
VAP	Ventilator associated pneumonia