Research in Medicine

 Introduction : which is manifested by reduction in arterial blood oxygen. The present study was conducted to evaluate the frequency, clinical and para clinical features of HPS, and to determine their predictive values in diagnosis in a group of Iranian patients .

 Materials and methods : consecutively to the gastroenterology department of Taleghani Hospital between 2003 and 2004. Patients underwent pulmonary echo-contrast to detect intra-pulmonary and intra-cardiac shunts. Arterial blood oxygen, 0 2 gradient (A-a) and orthodoxy were measured in these patients by ABG . All patients underwent endoscopy for possible esophageal varices. Patients who met the following three diagnostic criteria including hepatic cirrhosis , arterial blood deoxygenation (P0 2 <80 mmHg) and intrapulmonary arterial dilation were classified as clinical HPS while those manifested solely with intrapulmonary arterial dilation were defined as subclinical HPS .

 Results : aged 71-80 years were more commonly affected. Hepatitis B was the most common etiologic factor .

 Dyspnea (100%)and cyanosis (90%) were the most prevalent clinical features. Dyspnea and clubbing were the most sensitive and specific clinical features, respectively . Pao 2 <70 mmHg and arterial-alveolar gradient had the highest sensitivity for HPS diagnosis .

 Conclusion : negative predictive value (100%) were the best clinical features to diagnose HPS. PaO 2 <70 mmHg and P(A-a)0 2 >30 and their sum, have the highest positive and negative predictive values in HPS diagnosis .