Statistical Analysis:
SPSS v.24 (SPSS, Chicago, IL, USA) was used to perform the statistical analysis. Data presented as median with interquartile range or frequencies. Comparisons between groups analyzed by Mann– Whitney U-test; p < 0.05 considered significant. Pearson correlation was used to correlate between SpO2 and other variables, correlation was considered significant if r >0.5. GraphPad was used to instruct the correlation graph.