Pulmonary manifestations of liver diseases

Pulmonary Complications in Candidates for Liver Transplantation

The liver plays a pivotal role in maintaining the homeostasis of various organ systems. Also, end-stage liver disease and its complications are major causes of morbidity and mortality among adults. Individuals who develop a chronic liver disease are at increased risk of progression to multi-organ dysfunction, including the pulmonary system. The clinical complications of pulmonary problems related to the presence of liver disease range from mild (such as hypoxemia) to life-threatening diseases (such as portopulmonary hypertension and hepatopulmonary syndrome). Herein, the major pulmonary complications related to liver cirrhosis and considerations for performing liver transplantation are reviewed.

The Relationship Between Airway Occlusion Pressure and Severity of liver Cirrhosis in Candidates for Liver Transplantation

BACKGROUND End-stage cirrhosis is an irreversible condition, and liver transplantation is the only treatment option in for the affected patients. Respiratory problems and abnormal breathing are common findings among these patients. In this study, for the first time, we examined the relationship between the severity of liver cirrhosis and respiratory drive measured by mouth occlusion pressure (P_0.1). METHODS This was a cross-sectional study conducted on 50 candidates for liver transplantation who were referred to the pulmonary clinic of Imam Khomeini Hospital for pre-operative pulmonary evaluations. Arterial blood gas analysis (ABG), pulmonary function tests, and measurement of P0.1 were performed for all patients. The severity of liver disease was assessed using the Model for End-Stage Liver Disease (MELD) score. RESULTS The median P_0.1 was 5 cm H₂ O. P_0.1 was negatively associated with PaCO₂ (r = -0.466, p = 0.001) and HCO3 - (r = -0.384, p = 0.007), and was positively correlated with forced expiratory volume at 1s (FEV1 )/ forced vital capacity (FVC) (r = 0.282, p = 0.047). There was a strong correlation between P_0.1 and MELD score (r = 0.750, p < 0.001). Backward multivariate linear regression revealed that a higher MELD score and lower PaCO₂ were associated with increased P_0.1. CONCLUSION High levels of P_0.1 and strong direct correlation between P_0.1 and MELD score observed in the present study are suggestive of the presence of abnormal increased respiratory drive in candidates for liver transplantation, which is closely related to their disease severity.

Evaluation of Lung Function in Liver Transplant Candidates

INTRODUCTION

A wide variety of pulmonary conditions are found in cirrhotic patients and may compromise the pleura, diaphragm, parenchyma, and pulmonary vasculature, influencing the results of liver transplantation.

OBJECTIVE

To evaluate the pulmonary function (lung capacities, volumes, and gasometric study) of patients with liver cirrhosis awaiting liver transplantation.

PATIENTS AND METHODS

Cirrhotic patients, subdivided into 3 groups stratified by liver disease severity using the Child-Pugh-Turcotte score, were compared with a control group of healthy volunteers. In spirometry, the parameters evaluated were total lung capacity, forced volume in the first second, and the relationship between forced volume in the first minute and forced vital capacity. Blood gas analysis was performed. In the control group, arterial oxygenation was evaluated by peripheral oxygen saturation by pulse oximetry.

RESULTS

Of the 55 patients (75% men, 51 ± 12.77 years), 11 were Child A (73% men, 52 ± 14.01 years), 23 were Child B (75% men, 51 ± 12.77 years), and 21 were Child C (95% men, 50 ± 12.09 years). The control group had 20 individuals (50% men, 47 ± 8.15 years). Pulmonary capacities and volumes by the parameters evaluated were within the normal range. Arterial blood gas analysis detected no hypoxemia, but a tendency to low partial gas pressure was noted.

CONCLUSION

In this population of cirrhotic patients the parameters of spirometry were normal in relation to the lung capacities and volumes in the different groups. No hypoxemia was detected, but a tendency to hypocapnia in the blood gas was noted.

Pulmonary complications of hepatic diseases

Severe chronic liver disease (CLD) may result from portal hypertension, hepatocellular failure or the combination of both. Some of these patients may develop pulmonary complications independent from any pulmonary pathology that they may have. Among them the hepatopulmonary syndrome (HPS), portopulmonary hypertension (PPH) and hepatic hydrothorax (HH) are described in detail in this literature review. HPS is encountered in approximately 15% to 30% of the patients and its presence is associated with increase in mortality and also requires liver transplantation in many cases. PPH has been reported among 4%-8% of the patient with CLD who have undergone liver transplantation. The HH is another entity, which has the prevalence rate of 5% to 6% and is associated in the absence of cardiopulmonary disease. These clinical syndromes occur in similar pathophysiologic environments. Most treatment modalities work as temporizing measures. The ultimate treatment of choice is liver transplant. This clinical review provides basic concepts; pathophysiology and clinical presentation that will allow the clinician to better understand these potentially life-threatening complications. This article will review up-to-date information on the pathophysiology, clinical features and the treatment of the pulmonary complications among liver disease patients.

Portopulmonary hypertension

Portopulmonary hypertension (PoPH) refers to the condition that pulmonary arterial hypertension (PAH) occur in the stetting of portal hypertension. The development of PoPH is thought to be independent of the severity of portal hypertension or the etiology or severity of liver disease. PoPH results from excessive vasoconstriction, vascular remodeling, and proliferative and thrombotic events within the pulmonary circulation that lead to progressive right ventricular failure and ultimately to death. Untreated PoPH is associated with a poor prognosis. As PoPH is frequently asymptomatic or symptoms are generally non-specific, patients should be actively screened for the presence of PoPH. Two-dimensional transthoracic echocardiography is a useful non-invasive screening tool, but a definitive diagnosis requires invasive hemodynamic confirmation by right heart catheterization. Despite a dearth of randomized, prospective data, an ever-expanding clinical experience shows that patients with PoPH benefit from therapy with PAH-specific medications including with endothelin receptor antagonists, phosphodiesterase-5 inhibitors, and/or prostanoids. Due to high perioperative mortality, transplantation should be avoided in those patients who have severe PoPH that is refractory to medical therapy.

Hepatopulmonary syndrome among cirrhotic candidates for liver transplantation

This study assess of hepatopulmonary syndrome (HPS) prevalence and the influence of etiology among cirrhotic patients due to an alcoholic or viral etiology. We examined the records of patients were distributed as Group 1, alcoholic (n = 40) and Group 2, hepatic cirrhosis of viral etiology (n = 35). Hepatic cirrhosis status was estimated by CHILD and MELD scores. Presence of clinical ascites spell out was noted as well as size and diastolic functions of the cardiac chambers using two-dimensional transthoracic echocardiography in M mode and by Doppler. HPS was studied with agitated saline serum and intravenous contrast administration. HPS was considered to be present when serum or contrast passed to the left chamber before the 5th cardiac cycle. There was no significant differences among related to sex, age, cirrhosis status or ascites. HPS frequency was 35% in Group 1 versus 64.7% among Group 2-Patients (P = .01). Taking into account the results, we concluded that HPS frequency was related to cirrhotic etiology. Upon multivariate analysis a patients with cirrhosis from viral etiology showed significantly increased HPS frequency compared with those displaying cirrhosis of an alcoholic etiology.

Liver transplantation: Advances and perioperative care

Liver transplantation is one of the treatments for many-life threatening liver diseases. Numerous advances in liver transplant surgery, anaesthesia and perioperative care have allowed for an increasing number of these procedures. The purpose of this review is to consider some of the important advances in perioperative care of liver transplant patients such as pre-operative evaluation, intraoperative monitoring and management and early extubation. A PubMed and EMBASE search of terms “Anaesthesia” and “Liver Transplantation” were performed with filters of articles in “English”, “Adult” and relevant recent publications of randomised control trial, editorial, systemic review and non-systemic review were selected and synthesized according to the author's personal and professional perspective in the field of liver transplantation and anaesthesia. The article outlines strategies in organ preservation, training and transplant database for further research.

Evaluation of liver transplant candidates: A pulmonary perspective

Chronic liver disease is one of the leading causes of mortality and morbidity in the worldwide adult population. Liver transplant is the gold standard therapy for end-stage liver disease and many patients are on the waiting list for a transplant. A variety of pulmonary disorders are encountered in cirrhotic patients. Pleura, lung parenchyma, and pulmonary vasculature may be affected in these patients. Hypoxemia is relatively common and can be asymptomatic. Hepatopulmonary syndrome should be investigated in hypoxic cirrhotic patients. Gas exchange abnormalities are common and are generally correlated with the severity of liver disease. Both obstructive and restrictive types of airway disease can be present. Abnormal diffusion capacity is the most frequently observed pulmonary function disorder in patients with cirrhosis. Hepatic hydrothorax is another finding which is usually seen in conjunction with, but occasionally without ascites. Portopulmonary hypertension is a complication of long standing liver dysfunction and when severe, is accepted as a containdication to liver transplant. Since respiratory disorders are common and have significant impact on postoperative outcome in patients undergoing liver transplant, a careful preoperative pulmonary assessment is important.

Clinical study on pulmonary diffusion function in patients with chronic liver disease

OBJECTIVE

To investigate the influence of chronic liver disease (CLD) on pulmonary diffusion function.

METHODS

Arterial blood gas analysis, pulmonary function test, contrast-enhanced transthoracic echocardiography and technetium macro-aggregated albumin scanning were performed in 50 cirrhotic patients who underwent surgery on portal hypertension and liver transplantation. The severity of chronic liver disease (CLD) was evaluated by Child-Pugh-Turcotte (CPT) categorization and model for end stage liver disease (MELD) score from October 2008 to July 2009 in our surgical department and organ transplantation center.

RESULTS

A-aDO(2) was increased with the aggravation of liver dysfunction. The pulmonary diffusion capacity for carbon monoxide (DLCO) differed significantly among the three groups, which was (90.8 ± 7.3)% in CPT A group, (82.8 ± 10.8)% in CPT B group, and (73.5 ± 8.3)% in CPT C group. A-aDO(2) correlated positively with CPT (r= 0.581, P= 0.000) as well as the MELD score (r= 0.696, P= 0.000), whereas DLCO was negatively correlated with CPT (r=-0.630, P= 0.000) and the MELD score (r=-0.708, P= 0.000).

CONCLUSION

DLCO can be useful in the detection of pulmonary vascular abnormality of CLD. The MELD score may be a better criterion than the CPT score in assessing intrapulmonary vascular damage of CLD patients.

Portopulmonary hypertension and right heart failure in patients with cirrhosis

PURPOSE OF REVIEW

In 5-6% of patients with portal hypertension a pathological state exists in which changes in the pulmonary vasculature cause an increase in pulmonary vascular resistance. The resultant increased work of the right ventricle may cause right heart failure and liver congestion. Patients with cirrhosis are at increased risk of mortality and transplant graft failure. The present review examines the latest advances in diagnosis, treatment and management of portopulmonary hypertension.

RECENT FINDINGS

Portopulmonary hypertension may be screened with transthoracic echocardiography and following up with a right heart catheterization in patients in whom the right ventricular systolic pressure is calculated to be 50 mmHg or greater. Therapy with prostanoids, endothelin-1 inhibitors and phosphodiesterase-5 inhibitors, or a combination of therapies, may be very effective in moderating pulmonary artery hypertension and, in selected patients, allowing liver transplantation to proceed safely. The model for end-stage liver disease (MELD) score is being weighted to accelerate responders on the waiting list for a transplant.

SUMMARY

Advances in diagnosis and therapy of portopulmonary hypertension allow patients with cirrhosis who respond to vasodilators to undergo liver transplantation safely. Unfortunately liver transplantation does not always result in reversal of pulmonary hypertension. There are now reports of de-novo pulmonary hypertension after liver transplantation.

Paradoxical emboli secondary to hepatic pathology: common or coincidental?

Paradoxical cerebral emboli from cardiac and pulmonary sources are well described in the peer-reviewed literature. We outline a case with a hepatic etiology and describe diagnostic and management options. Though this paper represents the first documentation of such, we believe that transpulmonary shunting with concurrent paradoxical cerebral microemboli is more prevalent than recognized. We introduce this case report to compel practitioners to consider paradoxical emboli in selected cirrhotic patients since it can often be difficult to elicit subtle neurologic changes on clinical examination of patients with end stage liver disease.