3. Ashbaugh DG, Bigelow DB, Petty TL, Levine BE. Acute respiratory distress in adults. Lancet. 1967;290:319-23. 4. ARDS definition task force. Acute Respiratory Distress Syndrome: the Berlin definition. JAMA. 2012;307:2526-33. 5. Ferguson ND, Fan E, Camporota L, Antonelli M, Anzueto A,Beale R,et al. The Berlin definition of ARDS: an expanded rationale, justification, and supplementary material....

Introduction:  One ofdiagnostic criteria for Acute Lung Injury and Acute Respiratory Distress Syndrome is  pao2/fio2 (PF) ratio 300 for ALI or 200 for ARDS. This criteria requires invasive arterial sampling. Measurement of Spo2/Fio2 (SF) ratio by pulseoximetry may be a reliable non invasive alternative to the PF ratio.   Methods and Materials: In a cross sectional study we enrolled 105 sample o...