role of pulse oximetry in detecting mild to moderate hepatopulmonary syndrome in children

background : hepatopulmonary syndrome (hps) refers to arterial hypoxemia caused by pulmonary vasodilation, which is a consequence of portal hypertension. hps is associated with increased morbidity and mortality; thus, it is important to diagnose this entity as soon as possible for treatment to be administered. materials and methods: in a cross-sectional study, 40 children (6 months to 14 years old) with chronic liver disease were enrolled. in all patients, measurements of oxygen saturation (sao2) were performed with a pulse oximeter in the supine position (spo2) and then in the upright position (î”spo2). children were divided into three groups: i) those with both spo2›96% and î”spo2›4%; ii) children with either spo2›96% or î”spo2› 4%; and iii) those with neither of these signs. then, contrast-enhanced echocardiography (cee) and arterial blood gas (abg) were performed. finally, the prevalence of mild to moderate hps was calculated in the three groups. results: there were 30 patients who had neither of the two signs, of which 9 had hps. ten patients had one of the two signs, in whom 4 had hps. none of the patients had both signs. the sensitivity of the pulse oximetry was 30%, specificity was 77%, positive predictive value was 38% and negative predictive value was 70%. conclusion: there is a significant prevalence of hps in cirrhotic patients which effects prognosis. based on our study results, we have determined that pulse oximetry could not be a reliable screening procedure in mild to moderate hps. it is recommended to use gold standard tests (echocardiography and arterial blood gasometry) for the screening and diagnosis of hps in children.