validity of spo2 in measuring of oxygenation index

background pulse-oximetry (spo2) widely uses as a help tools for therapeutic interventions in the pediatric intensive care units (picu). the aim of this study was to evaluate the validity of spo2 in measuring of oxygenation index (oi) in children. materials and methods in a descriptive analytical study, 100 patients who were admitted to picu tabriz children's hospital were studied. oxygenation index measured by using two methods, including spo2 which obtained from spo2 and  partial pressure of oxygen in arterial blood (pao2) which obtained from arterial blood gases analysis. results based on findings, there was a linear correlation between spo2 and pao2, and also about oi which measured with spo2 and pao2.  based on receiver operating curve (roc), sensitivity and specificity of oi with considering pao2 as denominator and in values less or more than 0.145, were 100%, and 76.9%, respectively; and with considering spo2 as denominator and in values less or more than 0.145, were 98.6%, and 67.7%, respectively. conclusion this study indicates that spo2 instead of pao2 for measuring oi can be useful.