Comparison of the Spo^sub 2^/Fio^sub 2^ Ratio and the Pao^sub 2^/Fio^sub 2^ Ratio in Patients With Acute Lung Injury or Acute Respiratory Distress Syndrome

Diagnostic criteria for acute lung injury (ALI) and Acute Respiratory Distress syndrome (ARDS) includes acute onset of disease, chest radiograph demonstrating bilateral pulmonary infiltrates, lack of significant left ventricular dysfunction and Pao^sub 2^/Fio^sub 2^ (PF) ratio ≤300 for ALI or ≤200 for ARDS. In this cross-sectional study, the authors enrolled 70 patients with ALI or ARDS who were admitted in Tabriz children's hospital pediatrics intensive care unit. Spo^sub 2^, Fio^sub 2^, Pao^sub 2^, charted within 5 minutes of each other and calculated SF and PF were recorded to determine the relationship between SF and PF ratio. SF values were examined as a substitute of PF ratio for diagnosis ARDS and ALI. The relationship between SF and PF ratio was described by the following regression equation: SF=57+0.61 PF (P