Inhaled nitric oxide reduces pulmonary artery pressures in portopulmonary hypertension

Pulmonary Complications of Portal Hypertension

The most common pulmonary complications of chronic liver disease are hepatic hydrothorax, hepatopulmonary syndrome, and portopulmonary hypertension. Hepatic hydrothorax is a transudative pleural effusion in a patient with cirrhosis and no evidence of underlying cardiopulmonary disease. Hepatic hydrothorax develops owing to the movement of ascitic fluid into the pleural space. Hepatopulmonary syndrome and portopulmonary hypertension are pathologically linked by the presence of portal hypertension; however, their pathophysiologic mechanisms are significantly different. Hepatopulmonary syndrome is characterized by low pulmonary vascular resistance secondary to intrapulmonary vascular dilatations and hypoxemia; portopulmonary hypertension features elevated pulmonary vascular resistance and constriction/obstruction within the pulmonary vasculature.

Pulmonary Arterial Pressure Management Based on Oral Medicine for Pediatric Living Donor Liver Transplant With Portopulmonary Hypertension

Pediatric living donor liver transplantation (LDLT) in patients with advanced portopulmonary hypertension (PoPH) is associated with poor prognoses. Recently, novel oral medications, including endothelin receptor antagonists (ERAs), phosphodiesterase 5 (PDE5) inhibitors, and oral prostacyclin (PGI2) have been used to treat PoPH. Pediatric patients with PoPH who underwent LDLT from 2006 to 2016 were enrolled. Oral pulmonary hypertension (PH) medication was administered to control pulmonary arterial pressure (PAP). Four patients had PoPH. Their ages ranged from 6 to 16 years, and their original diseases were biliary atresia (n = 2), portal vein obstruction (n = 1), and intrahepatic portal systemic shunt (n = 1). For preoperative management, 2 patients received continuous intravenous PGI2 and 2 oral medications (an ERA alone or an ERA and a PDE5 inhibitor), and 2 received only oral drugs (an ERA and a PDE5 inhibitor). One patient managed only with intravenous PGI2 died. In the remaining 3 cases, intravenous PGI2 or NO was discontinued before the end of the first postoperative week. Postoperative medications were oral PGI2 alone (n = 1), an ERA alone (n = 1), or the combination of an ERA and a PDE5 inhibitor (n = 1). An ERA was the first-line therapy, and a PDE5 inhibitor was added if there was no effect. New oral PH medications were effective and safe for use in pediatric patients following LDLT. In particular, these new oral drugs prevent the need for central catheter access to infuse PGI2.

Perioperative Care of the Liver Transplant Patient

With the evolution of surgical and anesthetic techniques, liver transplantation has become "routine," allowing for modifications of practice to decrease perioperative complications and costs. There is debate over the necessity for intensive care unit admission for patients with satisfactory preoperative status and a smooth intraoperative course. Postoperative care is made easier when the liver graft performs optimally. Assessment of graft function, vigilance for complications after the major surgical insult, and optimization of multiple systems affected by liver disease are essential aspects of postoperative care. The intensivist plays a vital role in an integrated multidisciplinary transplant team.

Hemodynamic profile of portopulmonary hypertension

Portopulmonary hypertension (PPHTN) refers to the development of pulmonary arterial hypertension in the setting of portal hypertension with or without chronic hepatic failure. This syndrome is characterized by marked alternations of pulmonary vascular tone and obstruction of pulmonary arterial blood flow. An increased pulmonary blood flow, which is a hallmark of the hyperdynamic circulation of cirrhotic patients, seems to be present in almost all patients who develop PPHTN. The elevations of pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR) along with the transpulmonary gradient (TPG) have been considered in diagnosing PPHTN. Only a high TPG reflects the severity of obstruction to pulmonary blood flow and differentiates an elevated PAP with concomitant elevated PVR from the situation where the increase in PAP is due only to the hyperdynamic flow and elevated volume. A considerable risk for cardiovascular death arises when PAP increases significantly; this may occur in rapidly evolving syndromes, in very advanced disease, or during a complicated liver transplantation. The distinction between PPHTN and elevated PAP in the context of a hyperdynamic state is of great importance; a PAP increase of hyperkinetic origin, as opposed to PPHTN, is apparently not associated with a high risk for adverse effects during and following liver transplantation.

Hepatopulmonary syndrome and portopulmonary hypertension: recent knowledge in pathogenesis and overview of clinical assessment

Hepatopulmonary syndrome and portopulmonary hypertension are cardiopulmonary complications, which are not infrequently seen in patients with liver disease and/or portal hypertension. These entities are both clinically and pathophysiologically different: the hepatopulmonary syndrome is characterized by abnormal pulmonary vasodilation and right-to-left shunting resulting in gas exchange abnormalities, whereas portopulmonary hypertension is caused by pulmonary artery vasoconstriction leading to hemodynamic failure. As both hepatopulmonary syndrome and portopulmonary hypertension are associated with significantly increased morbidity and mortality, and as these patients are commonly asymptomatic, all liver transplantation candidates should be actively screened for the presence of these two complications. The aim of is this review is to provide an overview on the hepatopulmonary syndrome and portopulmonary hypertension with primary focus on diagnosis and recent knowledge regarding pathogenesis and therapeutic targets.

Oral vasodilator therapy in patients with moderate to severe portopulmonary hypertension as a bridge to liver transplantation

Portopulmonary hypertension (POPH) is a part of group 1 pulmonary hypertension (pulmonary hypertension associated with portal hypertension). Liver transplantation (LTx) may be curative, but is usually restricted to patients with mild-to-moderate POPH. The presence of severe POPH may be a contraindication to transplantation because of the elevated risk of peritransplantation and post-transplantation morbidity and mortality. This report describes a series of seven patients with onset of moderate (two patients) or severe (five patients) POPH before LTx, of whom six were treated with oral vasodilator therapy for POPH. Although previous studies recommend aggressive parenteral prostacyclin therapy (epoprostenol), we describe the opportunity to treat cases of severe POPH with an oral phosphodiesterase type 5 inhibitor (sildenafil) and/or an endothelin receptor antagonist (bosentan/ambrisentan) as a bridge to successful LTx in selected patients.

The heart in liver transplantation

The heart and liver are organs that are closely related in both health and disease. Patients who undergo liver transplantation may suffer from heart disease that is: (a) related to the original cause of the liver disease such as hemochromatosis, (b) related to the liver disease itself, or (c) related to other associated conditions. Furthermore, liver transplantation is one of the most cardiovascular stressful events that a patient with cirrhosis may undergo. After liver transplantation, the progression of pre-existing or the development of new-onset cardiac disease may occur. This article reviews the relationship between the heart and liver transplantation in the pre-transplant, intra-operative, and post-transplant periods.

Pulmonary manifestations of liver diseases

Respiratory problems are common in patients with chronic liver diseases. The most common causes are disorders that are not related to liver diseases such as asthma and COPD. In addition certain liver diseases that are associated with specific pulmonary abnormalities, and conditions associated with end stage liver disease like tense ascites and intercostal muscular wasting are considered. Finally two unique disorders characterizing by vascular abnormalities independent of cardiorespiratory disorder-the hepatopulmonary syndrome (HPS) and portopulmonary hypertension (POPH) are observed. These disorders have different pathogenesis, different clinical pictures, treatment and prognosis. This article reviews the epidemiology, pathophysiology, clinical features, evaluation and current therapy of these two disorders.

Initial experience using continuous intravenous treprostinil to manage pulmonary arterial hypertension in patients with end-stage liver disease

Treprostinil is a prostacyclin analog and has been used on idiopathic pulmonary arterial hypertension (PAH). There is only limited clinical experience using treprostinil to manage PAH in patients with end-stage liver disease (ESLD). We report three ESLD patients with PAH, who were treated with continuous intravenous treprostinil. A 59-year-old woman with ESLD secondary to alcoholic hepatitis had portopulmonary hypertension with mean pulmonary arterial pressure (mPAP) of 44 mmHg and transpulmonary gradient (TPG) of 23 mmHg. Treprostinil at 45 ng/kg/min for 6 months decreased mPAP to 23 (TPG to 8). A 53-year-old man had ESLD secondary to alcoholic hepatitis with PAH caused by multiple pulmonary embolisms (mPAP of 32 and TPG of 23). Treprostinil at 36 ng/kg/min for 3 months decreased mPAP to 23 and TPG to 14. Both patients underwent uneventful liver transplantation. A 48-year-old man had ESLD secondary to hepatitis C and portopulmonary hypertension with mPAP of 60 and TPG of 44. Two years after intravenous treprostinil at 106 ng/kg/min, his mPAP decreased to 44 and TPG to 30. These results demonstrate that for a selected group of ESLD patients with PAH, a continuous intravenous infusion of treprostinil appears to be safe and effective.

Assessment of acute pulmonary vascular reactivity in portopulmonary hypertension

The role of acute pulmonary vasodilator testing in portopulmonary hypertension (PoPH), a current contraindication for orthotopic liver transplantation (OLT), has not been thoroughly elucidated. The purpose of this work was to analyze the results of acute vasodilator testing with inhaled nitric oxide (NO), to compare them with intravenous epoprostenol (PGI(2)), and to investigate the acute effects of the oral vasodilator isosorbide-5-mononitrate (Is-5-MN), in patients with PoPH. A total of 19 patients with PoPH (male/female = 9/10) were studied. Pulmonary hemodynamic measurements were performed at baseline and during NO inhalation (40 ppm); additionally, 15 patients were tested with PGI(2) (2-12 mug/kg/minute) and 8 were tested with Is-5-MN (20-40 mg). Inhaled NO reduced pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR) by 5.7% and 11.0%, respectively. PGI(2) elicited greater reductions in PAP (11.8%) and PVR (-24.0%), and produced a 28% drop in systemic vascular resistance (SVR) and a 17% increase in the cardiac index (CI). Is-5-MN reduced PAP by 25.6% and PVR by 21.5%, without systemic changes. There was good agreement between the response to PGI(2) and Is-5-MN: 6 patients of the whole series (32%) decreased PAP >20% from baseline, reaching a final value < or = 35 mmHg, the current limit for OLT. In conclusion, acute vasodilator testing has a relevant role in PoPH, as it identifies one-third of patients able to reach a more favorable hemodynamic situation, which can be determinant for their management. For vasodilator testing, PGI(2) is more suitable than NO in PoPH. Is-5-MN exerts a selective effect on pulmonary circulation in patients who had already responded to PGI(2).

Portopulmonary hypertension

As a result of the success of orthotopic liver transplantation, there has been increasing interest in the diagnosis and therapeutic options for the pulmonary vascular complications of hepatic disease. These pulmonary vascular complications range from the hepatopulmonary syndrome, which is characterized by intrapulmonary vascular dilatations, to portopulmonary hypertension (POPH), which is characterized by an elevated pulmonary vascular resistance as a consequence of obstruction to pulmonary arterial blood flow. This review concentrates on POPH.

Epidemiology of Pulmonary Arterial Hypertension

Progress in understanding the basic biology and the development of new therapies for pulmonary arterial hypertension have led to improvements in survival. This article reviews clinically important changes in the classification of the pulmonary hypertensive diseases, as well as the epidemiology of various forms of pulmonary hypertension. The risk factors for the development of pulmonary arterial hypertension, prognostic markers, and the effects of current therapies on survival are discussed.

Pulmonary hypertension and beta-thalassemia major: report of a case, its treatment, and a review of the literature

Pulmonary hypertension is a common complication of beta-thalassemia major. We report a case of successful treatment of pulmonary hypertension in a patient with beta-thalassemia major and review the literature on pulmonary hypertension and beta-thalassemia major. A 28-year-old man with beta-thalassemia major, splenectomy, hepatitis C, and hemosiderosis who presented with increasing dyspnea on exertion was diagnosed with pulmonary hypertension. After receiving continuous epoprostenol infusion and desferoxamine, his functional capacity and hemodynamic status improved. To our knowledge, this is the first case of pulmonary hypertension associated with beta-thalassemia treated with continuous epoprostenol infusion and desferoxamine. Epoprostenol, beneficial in the treatment of other types of pulmonary hypertension, may ameliorate the morbidity and mortality of pulmonary hypertension associated with thalassemia.

Hepatitis C virus and the lung: implications for therapy

Hepatitis C virus (HCV) infection is a chronic blood-borne disease that affects > 4,000,000 individuals in the United States. The majority of individuals with HVC infection acquire a chronic hepatitis that predisposes them to the complications of cirrhosis and hepatoma. Chronic HCV infection is, however, associated with multiple extrahepatic manifestations as well, including recently recognized effects on the lung. These include primary effects on lung function, as well as secondary effects in the settings of progressive liver disease and drug treatment for HCV. In this article, we discuss the emerging clinical data that support a role for HCV infection in lung disease, describe the multiple pulmonary manifestations of this viral infection, and outline the therapies available for specific pulmonary complications of chronic HCV infection.

The transplant recipient for nontransplant surgery

The transplant recipient has traded a life-threatening illness for a chronically immunosuppressed state. Subsequent anesthetic management for non-transplant surgical procedures may be challenging. The anesthesia provider must be aware of the degree of post-transplant organ dysfunction and alter anesthesia techniques accordingly. This article reviews the anesthetic concerns for patients who have undergone a variety of organ transplants.

Effects of terlipressin on systolic pulmonary artery pressure of patients with liver cirrhosis: An echocardiographic assessment

AIM: Portopulmonary hypertension is a serious complication of chronic liver disease. Our aim was to search into the effect of terlipressin on systolic pulmonary artery pressure among cirrhotic patients.

METHODS: Twelve patients (6 males and 6 females) with liver cirrhosis were recruited in the study. Arterial blood gas samples were obtained in sitting position at rest. Contrast enhanced echocardiography and measurements of systolic pulmonary artery pressure were performed before and after the intravenous injection of 2 mg terlipressin.

RESULTS: Of 12 patients studied, the contrast enhanced echocardiography was positive in 5, and the positive findings in contrast enhanced echocardiography were reversed to normal in two after terlipressin injection. The mean systolic pulmonary artery pressure was 25.5 ± 3.6 mmHg before terlipressin injection, and was 22.5 ± 2.5 mmHg after terlipressin (P = 0.003). The systolic pulmonary artery pressure was above 25 mmHg in seven of these 12 patients. After the terlipressin injection, systolic pulmonary artery pressure was < 25 mmHg in four of these cases (58.3% vs 25%, P = 0.04).

CONCLUSION: Terlipressin can decrease the systolic pulmonary artery pressure in patients with liver cirrhosis.

Portopulmonary hypertension: a tale of two circulations

Pulmonary involvement is common in patients with portal hypertension and can manifest in diverse manners. Changes in pulmonary arterial resistance, manifesting either as the hepatopulmonary syndrome or portopulmonary hypertension (PPHTN), have been increasingly recognized in these patients in recent years. This review summarizes the clinicopathologic features, diagnostic criteria, as well as the latest concepts in the pathogenesis and management of PPHTN, which is defined as an elevated pulmonary artery pressure in the setting of an increased pulmonary vascular resistance and a normal wedge pressure in a patient with portal hypertension.

Hepatopulmonary Syndrome and Portopulmonary Hypertension

In patients with hepatopulmonary syndrome, supplemental oxygen and liver transplantation are the usual treatments of choice. Pharmacologic approaches have limited success in improving hypoxemia. Interventional radiology procedures may improve arterial hypoxemia in highly selected patients. In patients with portopulmonary hypertension, continuous infusion with intravenous epoprostenol (prostaglandin I(2)) can significantly improve pulmonary hemodynamics. Outcome following liver transplantation is variable; increased cardiopulmonary mortality occurs in patients with moderate to severe pulmonary hypertension.

Intra-operative use of inhaled vasodilators: are there indications?

The US Food and Drug Administration and European authorities have recently approved inhaled nitric oxide for the treatment of neonates with hypoxic respiratory failure associated with pulmonary hypertension. In addition to this highly specific condition, there is an increasing 'off-label' use of inhaled nitric oxide and other inhaled vasodilators in the perioperative setting. Potential indications include right heart failure as a result of acute pulmonary hypertension in cardiac and non-cardiac surgery, the prevention of reperfusion injury in lung transplantation, the treatment of hypoxaemia during single-lung ventilation, and more recently, the treatment of sickle cell crisis.

Hepatopulmonary Syndrome and Portopulmonary Hypertension

In patients with hepatopulmonary syndrome, supplemental oxygen and liver transplantation are the usual treatments of choice. Pharmacologic approaches have limited success in improving hypoxemia. Interventional radiology procedures may improve arterial hypoxemia in highly selected patients. In patients with portopulmonary hypertension, continuous infusion with intravenous epoprostenol (prostaglandin I(2)) can significantly improve pulmonary hemodynamics. Outcome following liver transplantation is variable; increased cardiopulmonary mortality occurs in patients with moderate to severe pulmonary hypertension.