Hepatopulmonary syndrome: prevalence and clinical profile

BACKGROUND

The hepatopulmonary syndrome (HPS) is defined as a triad of liver dysfunction, intrapulmonary vascular dilatations (IPVD) and arterial hypoxemia. There is paucity of Indian studies regarding the prevalence of IPVD and arterial hypoxemia particularly amongst patients with non-cirrhotic portal fibrosis (NCPF) and extrahepatic portal vein obstruction (EHPVO), where liver dysfunction is not a feature.

METHODS

All patients with portal hypertension and esophageal varices seen at a tertiary care hospital during 1995-98 were studied. Ultrasonography of abdomen, contrast-enhanced echocardiography (CEE), arterial blood gas analysis and assessment of alveolar-arterial oxygen gradient were done.

RESULTS

Of 138 patients with portal hypertension seen during the study period, 88 fulfilled the inclusion and exclusion criteria. These included 63 with cirrhosis, 15 with NCPF and 10 with EHPVO. CEE showed IPVD in 17 (27%) patients with cirrhosis, of which 11 (17.5%) fulfilled the criteria for HPS. IPVD were also noted in 4 (26.6%) cases of NCPF and 3 (30%) of EHPVO, though only 2 (13.3%) and 1 (10%) respectively had elevated alveolar-arterial gradient and liver dysfunction in addition. Age and sex distribution and duration of symptoms were not different in patients with HPS. Patients with HPS had higher incidence of dyspnea, platypnea, clubbing and spider nevi.

CONCLUSIONS

Hepatopulmonary syndrome is present in 17.5% of cirrhotics, 13.3% of patients with NCPF and 10% with EHPVO. Patients with HPS had significantly higher incidence of dyspnea, platypnea, clubbing and spider nevi.

The hepatopulmonary syndrome

The hepatopulmonary syndrome is a triad of liver disease, increased alveolar-arterial oxygen gradient and intrapulmonary vascular dilatations. Manifestations include orthodeoxia, platypnoea and hyperdynamic circulation. Intrapulmonary vascular abnormalities, perhaps mediated by nitric oxide, cause hypoxaemia by shunting, a perfusion-diffusion defect, and ventilation-perfusion mismatching. Contrast-enhanced echocardiography is the method of choice for demonstrating pulmonary vascular abnormalities, although perfusion lung scanning is a more specific and sensitive test. Angiography is best reserved for patients with poor response to 100% oxygen and defines whether vascular dilatations are of the diffuse 'spongy' type or, less commonly, discrete arteriovenous communications amenable to embolization. About 80% of patients with the hepatopulmonary syndrome eventually have improved oxygenation after liver transplantation, thereby making worsening hypoxaemia the primary indication for transplantation in many instances. Nevertheless, severe hypoxaemia carries a peri-operative mortality of 30% and reliable predictors of successful outcome after transplantation remain to be determined.

Rehabilitating patients with hepatopulmonary syndrome using living-related orthotopic liver transplant: a case report

The objective of this study was to rehabilitate a patient with hepatopulmonary syndrome (HPS) who underwent living-related orthotopic liver transplantation (LT). HPS is rare; it presents severe complication in patients with liver disease. A 17-year-old woman with HPS developed portal hypertension after undergoing Kasai's surgery for congenital biliary atresia and underwent a living-related orthotopic LT. After LT, her allograft functioned well, but she continued to have hypoxemia and orthodeoxia. She was referred for rehabilitation for disuse atrophy, contracture of hip and shoulder joints, left common peroneal nerve palsy, and rehabilitation for respiratory dysfunction. By day 106 after LT, her orthodeoxia and disuse atrophy had improved because of daily exercise training and active joint range of motion exercises. Patients with HPS have orthodeoxia and poor responsiveness to oxygen therapy, and correction of hypoxemia after LT may be delayed. Therefore, rehabilitation approaches for patients with HPS should be based on the pathophysiology and characteristics of HPS.

[Cyanosis and cirrhosis of liver: hepatopulmonary syndrome]

A 66-year-old man with Child-B alcoholic cirrhosis presented with melaena due to hemorrhagic gastritis. Clinical examination revealed cyanosis and clubbing accompanied by severe hypoxaemia without signs of obstructive or restrictive lung disease. Contrast-enhanced echocardiography showed right to left shunt due to intrapulmonary shunting leading to the diagnosis of hepatopulmonary syndrome. Hypoxaemia in patients suffering from chronic liver disease can have different causes but in the presence of cyanosis and clubbing without signs of lung disease the hepatopulmonary syndrome should be suspected. When presence of intrapulmonary shunts has been proven by contrast-enhanced echocardiography, a 100% oxygen test can determine the need for pulmonary angiography and thus determine the indication for interventional therapy or liver transplantation. The patient described was treated supportively with long-term oxygen therapy 6 l/min. Three months later his clinical condition was stable. An attempt to reduce the need for nasal oxygen failed.

Hepatopulmonary syndrome: a prospective study of relationships between severity of liver disease, PaO(2) response to 100% oxygen, and brain uptake after (99m)Tc MAA lung scanning

BACKGROUND

Because of the spectrum of intrapulmonary vascular dilation that characterizes hepatopulmonary syndrome (HPS), PaO(2) while breathing 100% oxygen varies. Abnormal extrapulmonary uptake of (99m)Tc macroaggregated albumin (MAA) after lung perfusion is common.

GOAL

To describe relationships between (1) severity of liver disease measured by the Child-Pugh (CP) classification; (2) PaO(2) while breathing room air (RA) and 100% oxygen on 100% oxygen; and (3) extrapulmonary (brain) uptake of (99m)Tc MAA after lung scanning.

METHODS AND PATIENTS

We prospectively measured PaO(2) on RA, PaO(2) on 100% oxygen, and brain uptake after lung perfusion of (99m)Tc MAA in 25 consecutive HPS patients.

RESULTS

Mean PaO(2) on RA, PaO(2) on 100% oxygen, PaCO(2) on RA, and (99m)Tc MAA brain uptake were similar when categorized by CP classification. Brain uptake was abnormal (> or = 6%) in 24 patients (96%). Brain uptake was 29 +/- 20% (mean +/- SD) and correlated inversely with PaO(2) on RA (r = -0.57; p<0.05) and PaO(2) on 100% oxygen (r = -0.41; p<0.05). Seven patients (28%) had additional nonvascular pulmonary abnormalities and lower PaO(2) on 100% oxygen (215+/-133 mm Hg vs 391+/-137 mm Hg; p<0.007). Eight patients (32%) died. Mortality in patients without coexistent pulmonary abnormalities was associated with greater brain uptake of (99m)Tc MAA (48+/-18% vs 25+/-20%; p<0.04) and lower PaO(2) on RA (40+/-7 mm Hg vs 57+/-11 mm Hg; p<0.001).

CONCLUSION

The degree of hypoxemia associated with HPS was not related to the CP severity of liver disease. HPS patients with additional nonvascular pulmonary abnormalities exhibited lower PaO(2) on 100% oxygen. Mortality was associated with lower PaO(2) on RA, and with greater brain uptake of (99m)Tc MAA.

Pulmonary infarction after liver transplant and previous hepatopulmonary syndrome

We describe the case of a 36-year-old woman with previous hepatopulmonary syndrome in which a focal pulmonary lesion developed after liver transplantation. Thoracoscopic resection showed a pulmonary infarction of the superior segment of the right lower lobe. The patient recovered and had no further thrombotic events after 2 years of follow-up. The pulmonary vascular changes observed during hepatopulmonary syndrome may predispose patients to the development of pulmonary infarction.

Diseases of the hepatopulmonary axis

Hepatopulmonary syndrome is the most widely recognized of the processes associated with end-stage liver disease. Chronic liver dysfunction is associated with pulmonary manifestations due to alterations in the production or clearance of circulating cytokines and other mediators. Hepatopulmonary syndrome results in hypoxemia due to pulmonary vasodilatation with significant arteriovenous shunting and ventilation-perfusion mismatch. Hepatic hydrothorax may develop in patients with cirrhosis and ascites. Rarely, pulmonary hypertension occurs in the setting of portal hypertension. A second group of disorders may primarily affect the lungs and liver (the hepatopulmonary axis). Among these are the congenital conditions alpha(1)-antitrypsin deficiency and cystic fibrosis. Autoimmune liver disease may be associated with lymphocytic interstitial pneumonitis, fibrosing alveolitis, intrapulmonary granulomas, and bronchiolitis obliterans with organizing pneumonia. Sarcoidosis affects the lung and liver in up to 70% of patients. Medications such as amiodarone can result in a characteristic radiologic appearance of pulmonary and hepatic toxic effects. Knowledge of these associations will assist the radiologist in forming a meaningful differential diagnosis and may influence treatment decisions.

Hepatopulmonary syndrome

Hepatopulmonary syndrome is caused by intrapulmonary vasodilation that leads to abnormal arterial gas exchange in the setting of liver disease or portal hypertension. It is seen in up to 15% of cirrhotics and is an increasingly common indication for liver transplantation. Testing for the presence of oxygenation abnormalities and intrapulmonary vasodilation is needed to make the diagnosis. Excess production of nitric oxide in the lung contributes to pulmonary vasodilation and may be triggered by the release of mediators from the damaged liver. No medical therapies are established as effective, and liver transplantation is the only documented curative treatment.

[Hepatopulmonary syndrome: physiopathology of impaired gas exchange]

The hepatopulmonary syndrome (HPS) consists of a triad of liver dysfunction, increased alveolar-arterial oxygen gradient and intrapulmonary vascular dilations. The mechanisms of impaired arterial oxygenation are still debated but the multiple inert gases elimination technique and more recently contrast echocardiography, greatly facilitated the investigation of such mechanisms. Subsequently the cause of hypoxemia can be attributed to several mechanisms such as ventilation-perfusion mismatch, right-to-left intrapulmonary shunts and alveolar-to-capillary diffusion defect, variously implicated in the severity of the disease. SHP may result from intrapulmonary vascular dilations and angiogenesis but the pathogenesis of such abnormalities is not completely explained. The hypothesis of an imbalance in vasoactive mediators and angiogenic factors has been put forward. Increasing data support the theory that the increase in synthesis and release of nitric oxide (NO) is the key factor modulating vascular tone. If this hypothesis is true, the use of compettive inhibitors of NO synthesis should restore pulmonary vascular tone, reversing the hemodynamic changes and gas exchange impairment of HPS.

[Hepatopulmonary syndrome]

ANAMNESIS

We report about a 60-year-old woman with hepatopulmonary syndrome. The patient suffered from progressive dyspnea and liver cirrhosis following viral hepatitis C, acquired through blood transfusion 30 years ago.

EXAMINATION RESULTS

Remarkable were clinical signs of chronic liver disease (cutaneous spider naevi, palmar erythema) and signs of chronic respiratory failure (clubbing) with platypnea. Arterial pO2 was 33 mm Hg under 41 O2/min nasal oxygen supplement and improved to 74 mm Hg under 81 O2/min. Arterial pO2 deteriorated in upright position (orthodeoxia). Contrast enhanced two-dimensional transthoracic echocardiography showed a delayed microbubble opacification in the left heart chambers (without atrial or ventricular septal defect), suggesting pulmonary vascular dilatations. Perfusion scan with macroaggregated albumin labelled with technetium-99m showed uptake over thyroid, kidneys, liver, and spleen suggesting an abnormal passage through the pulmonary vascular bed. The radiological examination with chest radiography and high resolution computer tomography revealed no signs of interstitial lung disease. The pulmonary artery angiography showed neither anatomical shunts nor malformations.

DIAGNOSIS

The final diagnosis was hepatopulmonary syndrome Type 1. TREATMENT/FOLLOW-UP: The patient underwent liver transplantation with following good function of the liver graft. After 6 months the patient presented in a much better general condition, but with persisting severe hypoxemia whereas the spider naevi disappeared completely. One year after the liver transplantation in the perfusion scan the uptake over thyroid, kidneys, liver, and spleen was absent. The orthodeoxia and hypoxemia improved evidently. From that we conclude that the pulmonary vascular dilatations diminished after liver transplantation.

Hepatopulmonary syndrome

The hepatopulmonary syndrome (HPS) is a rare complication of liver cirrhosis and is characterised by the typical triad of liver cirrhosis, arterial hypoxemia, and intrapulmonary vascular dilatation. Except for pleural effusions associated with liver cirrhosis no other disease of the lungs or the heart is detectable. The structural hallmark of HPS is dilatation of pulmonary precapillary vessels which impairs diffusion-perfusion and causes unequal ventilation-perfusion. The diagnosis of HPS is based on PaO2 measurements when breathing room air and 100% oxygen. The increased intrapulmonary vascular diameter allows microbubbles to traverse the lung capillaries when agitated saline is administered intravenously. Only on rare occasions is a patient limited by his pulmonary impairment, the leading morbidity is that of liver disease and its classical complications. Drug therapy is of no proven benefit, oxygen supplementation might improve dyspnea. Vascular embolisation of discrete arteriovenous shunts, if present, or liver transplantation may dramatically improve pulmonary function in selected patients.

Severe intrapulmonary shunting associated with metastatic carcinoid

A 37-year-old woman with a 10-year history of metastatic carcinoid presented to her oncologist with increased dyspnea. Further evaluation revealed hypoxemia and intrapulmonary vasodilatation. We describe a case of hepatopulmonary-like physiology associated with metastatic carcinoid in a patient with intact liver function. To our knowledge, this is the first documented case of intrapulmonary shunting and hepatopulmonary-like physiology associated with metastatic carcinoid.

The hepatopulmonary syndrome

The hepatopulmonary syndrome is a disease entity seen in association with liver failure and other disease entities. It is a devastating consequence of liver failure that results in a significant morbidity for affected patients. Currently, there are no identified medications that ameliorate the symptoms of hypoxemia in this disease state. Recent research, however, has begun to unravel the pathobiology of the vascular dilations that arise in the lungs of patients with liver failure. In this article, a compendium of current knowledge is presented, as well as the contemporary methods for identifying and treating patients.

Evaluation of contrast echocardiography and lung perfusion scan in detecting intrapulmonary vascular dilatation in normoxemic patients with early liver cirrhosis

BACKGROUND/AIMS

Intrapulmonary vascular dilatations (IPVD) are extrahepatic complications occurring in liver transplant candidates, that can result in severe hypoxemia. The aim of this study was to compare the use of two diagnostic modalities, contrast echocardiography and lung perfusion scan, in detecting IPVD in normoxemic patients with early liver cirrhosis.

METHODOLOGY

Fifty-six consecutive outpatients with biopsy-proven cirrhosis had contrast-echocardiography, a lung perfusion scan, pulmonary function tests, and arterial blood gas estimations. All patients were grade A or B according to the Child-Pugh classification. Patients with chronic intrinsic lung disease, heart failure or malignancy were excluded from the study.

RESULTS

All patients had normal arterial blood-gas analyses. Eight out of 56 patients (14.3%) had a positive contrast echocardiogram, all with a decreased diffusion capacity (DLCO < 75% of the predicted value). An isolated DLCO impairment was observed in 40% of the patients with normal spirometry. None of the patients with echocardiography-proven IPVD had a positive lung perfusion scan (p<0.005).

CONCLUSIONS

In normoxemic cirrhotic patients, subclinical pulmonary vasodilatation and gas-exchange abnormalities can occur. Contrast-enhanced echocardiography is the most valuable screening test in detecting IPVD in the early stages of hepatic insufficiency.

Treatment of hepatopulmonary syndrome with Allium sativum L. (garlic): a pilot trial

No medical therapy exists for subjects with hepatopulmonary syndrome (HPS). A patient with HPS was reported to have improvement in arterial oxygenation while self-administering garlic. Our goal was to determine whether a standardized garlic powder improves arterial oxygenation and dyspnea in subjects with HPS. A prospective, open label uncontrolled pilot study in 15 subjects with HPS were administered garlic powder capsules daily for a minimum of 6 months. Arterial blood gases were determined every 4-8 weeks, in the same position on room air, and a subjective dyspnea transition index was reported. Six of 15 subjects (40%, confidence interval: 0.15-65) had at least a 10 mmHg increase in the P(O2) or decrease in the alveolar-arterial gradient. The mean pre- and postarterial difference in these patients were: P(O2) (14+/-4 mmHg) and alveolar-arterial gradient (18+/-5 mmHg). All 6 subjects who responded to garlic had less dyspnea on exertion. Garlic improved arterial oxygenation in younger subjects (mean 40 versus 56 years old; p = 0.021) or those with lower macroaggregated albumin shunt fractions (mean 21 versus 44%, p = 0.058). Garlic may improve arterial oxygenation and symptoms in patients with hepatopulmonary syndrome and warrants further investigation.

Diagnosis of hepatopulmonary syndrome with contrast transthoracic echocardiography and histological confirmation

We report a patient with cirrhosis and hepatopulmonary syndrome. This syndrome is an entity characterized by anomalies in the arterial oxygenation in patients with chronic hepatic disease and/or portal hypertension and demonstration of pulmonary vasodilatation (PV) in absence of primary cardiac or pulmonary disease. We show that the finding of PV with transthoracic contrast enhanced echocardiography (TCEE) in the diagnosis of PV is real and corresponds to direct measurement of capillary diameter by morphometry.