Hepatopulmonary syndrome is the clinical relationship between hepatic dysfunction and the existence of pulmonary vascular dilatations which can ensue in a range of arterial oxygenation abnormalities.

Hepatopulmonary syndrome is the clinical relationship between hepatic dysfunction and the existence of pulmonary vascular dilatations which can ensue in a range of arterial oxygenation abnormalities.[1,2] The first published description of an interaction between the liver and the lung dates back to a clinical observation in 1884 through Fluckiger,[3] who described the coexistence of cyanosis, digital clubbing, and cirrhosis presumably caused on syphilis in a 37-year-old woman. A later report from Snell in 1935[4] described three patients who had liver disease with hemoglobin desaturation, yet it was not until 1956 that Rydell and Hoffbauer[5] described the detailed clinical course and autopsy deduction in a 17-year-old boy who readyed with juvenile cirrhosis. During the nearest 3 years, his course was complicated from progressive dyspnea with documented pulmonary vascular shunting (40 percent of the cardiac output) and hemoglobin desaturation (73 percent) The patient died 8 years later from progressive hepatic and cardiac failure, and at autopsy, dilated pulmonary ducts and direct arteriovenous communications were identified. The bourn "hepatopulmonary syndrome" was subsequently put in mind ofed by Kennedy and Knudson,[6] who described a patient in whom exertional dyspnea lay opened 4 years after portacaval shunting for complications of alcoholic cirrhosis.

Indeed, arterial oxygenation abnormalities are public in patients with hepatic diseases; new series have reported that 45 to 69 percent of liver transplant candidates have abnormal arterial oxygenation.[7,8] Hypoxemia caused according to hepatopulmonary syndrome, however, is distinctly extraordinary It is of substantial clinical importance because the measure of hypoxemia may be far-reaching (arterial partial pressure of oxygen [PaO.sub.2] les than 55 mm Hg) notwithstanding responsive to therapeutic interventions. one time considered to be an absolute contraindication to liver transplantation,[9] bitter hypoxemia due to this syndrome is now a relative contraindication[10] and may well be an indication for transplantation in pickeded patients.[11,12]

In this review, we describe the definition and clinical features of this syndrome and passing from hand to hand thoughts about its pathophysiology, the use of diagnostic imaging, and therapeutic approaches, including fresh results of liver transplantation.

DEFINITION OF THE SYNDROME

The syndrome can be defined as a clinical triad of (1) liver disease, (2) increased alveolar-arterial gradient breathing field air, and (3) evidence of intrapulmonary vascular dilatations. This definition is consistent with the diagnostic criteria lately suggested by Rodriguez-Roisin et al,[2] with single difference. The existence of other pulmonary abnormalities is habitual in patients with liver disorders (for example, pleural effusions or expiratory airflow obstruction as a issue of smoking). These kinds of abnormalities may coexist with hepatopulmonary syndrome; hence, the clinician should not be dissuaded from entertaining a diagnosis of hepatopulmonary syndrome

CLINICAL PRESENTATION

The signs and symptoms of liver disease are the most numerous common presentation in patients subsequently diagnosed with hepatopulmonary syndrome In a novel study of 22 patietns with this syndrome at the Mayo Clinic,[12] 82 percent of patients was initially evaluated for ascites, gastrointestinal bleeding, abnormal arises of liver function testing, hepatosplenomegaly, or jaundice. The mean duration of respiratory symptoms (primarily dyspnea) until the diagnosis of hepatopulmonary syndrome was 48 [+ or -] 25 years. In 18 percent of patients, dyspnea was the presenting symptom and liver disease was diagnosed in following evaluations.

Both acute and chronic liver diseases have been associated with pulmonary vascular dilatations and rigid hypoxemia.[12] Most commonly, hepatopulmonary syndrome currents in patients with chronic liver diseases resulting in cirrhosis, especially cryptogenic cirrhosis, alcoholic cirrhosis, chronic active hepatitis, and primary biliary cirrhosis. However, the finding of hepatopulmonary syndrome in patients with noncirrhotic portal hypertension[12,13] hints that portal hypertension may be the predominant factor related to this syndrome There appears to be no relationship between hepatopulmonary syndrome and biochemical measures of hepatic function (prothrombin time, albumin, bilirubin, and liver enzyme values), ascites, or gastrointestinal bleeding.[12] A modern report suggested an association with the class of esophageal varices;[14] cutaneous spider nevi have a stout association with the hepatopulmonary syndrome[15]

Hepatopulmonary syndrome has been documented 3 to 7 years after surgical portocaval shunting[6,16-18] and splenorenal shunting.[11,16,19] The syndrome has also been reported as a possible connection of hepatic rejection after auspicious liver transplantation for biliary atresia in a child.[20]

The most numerous striking physical findings are clubbing of the digits and cyanosis in patients with substantial hypoxemia. Findings forward examination of the chest are usually unremarkable. The in the greatest degree common pulmonary symptom in these patients is dyspnea, which may be worse with exercise or when the patient assumes the standing position (platypnea).[6,12,21]

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