Correlation Between the Ratio of Oxygen Saturation to Fraction of Inspired Oxygen and the Ratio of Partial Pressure of Oxygen to Fraction of Inspired Oxygen in Detection and Risk Stratification of Pediatric Acute Respiratory Distress Syndrome

Objective: To measure the correlation between the ratio of oxygen saturation to fraction of inspired oxygen [SpO(2)/FiO(2) (SF)] and the ratio of partial pressure of oxygen to fraction of inspired oxygen [PaO(2)/FiO(2) (PF)] among children diagnosed with acute respiratory distress syndrome (ARDS). Methodology: A cross-sectional study was conducted at the pediatric intensive care unit (PICU), National Institute of Child Health (NICH), Karachi, a tertiary care government hospital, from November 2020 to July 2021. One hundred twenty children (of either gender) having the age range of 2 months to 16 years, admitted to PICU with acute onset of respiratory distress, were included in the study. We measured SpO(2), PaO(2), FiO(2) and calculated SF and PF ratios. SPSS (version 23) (Armonk, NY: IBM Corp) was used to analyze data, and the Spearmen's correlation test was applied to measure the relationship between SF and PF ratios. Results: A total of 120 children were included, the mean age was 40.58±38.88 months and 67 (55.8%) were males. The mean FiO(2) was 76.33%, the mean PaO(2) and SpO(2) were 100.35 mmHg and 94.37%, respectively. The mean PF ratio was 156.34, and the mean SF ratio was 156.45. There was a strong correlation between the SF ratio and the PF ratio (r=0.688; p=0.001). Conclusion: This study has shown that there is a strong correlation between the SF and PF ratios, and a statistically substantial agreement has been observed.