Etiology and incidence of hypoxemia which is a diagnostic criteria for hepatopulmonary syndrome in liver cirrhosis

SUMMARYThe clinical presentation characterized by hypoxemia in patients with cirrhosisand acute hepatic failure in the absence of primary cardiac and pulmonary disease iscalled as Hepatopulmonary Syndrome (HPS). While breathing room air increase inalveolary-arterial oxygen gradient and intrapulmonary vascular dilatation accompanieshepatic disease in HPS.In chronic hepatic disease hypoxia development due to venous shunts iscommon. We aimed to determine the incidence of hypoxemia; a diagnostic criteria forHPS, preliminary symptoms of this entity and the facts augmenting hypoxemia.Thirty- nine cirrhotic patients (24 men, 15 women) were enrolled into the study.Age ranged from 12 to 70 years and the average age was 47.5±17.2 years. Completeblood count, routine biochemical analysis, protrombin time, international normalizationratio (INR), chest radiogram, arterial blood gases and pH measurements, uppergastrointestinal endoscopy and ultrasonography, breathing function tests and carbonmonoxide diffusion capacity measurements were obtained in all patients.Dyspnea (12), platypnea (6), hypoxia (13), clubbing (3), cyanosis (6),esophageal varices (12), portal gastropathy (2), both esophageal varices and portalgastropathy (19), and ascites (21) were most common symptoms and clinical findings.Seven, 21 and 11 patients were classified as having Child class A, B and C diseaserespectively. There was no influence of hypoxemia on liver function tests. PaO2 and sO2were found lower in patients with ascites compared to patients without ascites and thedifference between two groups were statistically significant (p:0.035 and 0.049respectively). Although the difference was not statistically significant, patients in ChildA class had reduced PaO2 levels with respect to Child B and C classes (p:0.921).DLCO found reduced in 46.2% of patients and this result was compatible withthe literature. When results of breathing function tests were evaluated FEV1, FVC,FEV1/FVC and FEF%25-75 were found lower in patients with ascites with respect topatients without ascites. However, the difference showed statistical significance onlyfor FEV1/FVC and FEF%25-75 (p:0.021 and 0.030 respectively). The results of diffusiontests were similar in two groups.44Consequently, in order to document HPS in cirrhotic patients and especially inpatients who will undergo liver transplantation obtaining chest radiograms, breathingfunction tests and analysis of arterial blood gases and diffusion capacity (in room andat the sitting position) is essential. In patients who had PaO2 level equal or lower than70 mmHg further investigations for the presence of shunts must be employed. Mostuseful techniques for shunt investigation are contrast echocardiography, 99 m Tc MAApulmonary perfusion sintigraphy and pulmonary angiography.45