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 (ΔSPO2). Children were divided into three groups: i) those with both SPO2›96% and ΔSPO2›4%; ii) children with either SPO2›96% or ΔSPO2› 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.