Pulmonary manifestations of chronic liver disease: a comprehensive review

Hemodynamic and Clinical Response to Liver Transplantation in Children and Young Adults POPH Patients

Portopulmonary hypertension is an intractable form of pulmonary hypertension. Although liver transplantation is recommended for patients who respond poorly to treatments, the mechanisms by which liver transplantation improves pulmonary hypertension remain unclear. The present study investigated these mechanisms by retrospectively evaluating patients' data. This study retrospectively evaluated echocardiography and catheterization data before and after liver transplantation in 12 patients who underwent liver transplantation from 2001 to 2019. The 12 patients included one male and 11 females, of median age at liver transplantation of 10 years, 2 months. Nine patients underwent liver transplantation for congenital biliary atresia and three for portal vein aplasia or hypoplasia. Mean pulmonary arterial pressure was 44.1 ± 8.1 mmHg at the first cardiac catheter examination, 35.3 ± 7.8 mmHg before liver transplantation, and 29.5 ± 9.3 mmHg 6 months after liver transplantation. Pulmonary artery pressure was reduced by treatments of pulmonary hypertension and by liver transplantation. Pulmonary vascular resistance did not differ before and after liver transplantation, whereas the cardiac index decreased significantly, indicating that the significant reduction in mean pulmonary artery pressure was due to a decrease in cardiac index. Decreased cardiac index was thought to result from improvements in hyperdynamic conditions due to increased (normalized) systemic vascular resistance. Liver transplantation likely suppresses shear stress on pulmonary arteries, preventing further damage by hyper-circulation. A longer-term evaluation is required to determine the effect of improving pulmonary artery remodeling.

Portopulmonary hypertension: peculiarities of diagnosis and treatment

Portopulmonary hypertension is defined as the development of pulmonary hypertension secondary to portal one. Its exact prevalence is difficult to determine due to the lack of routine screening in patients with portal hypertension. Hemodynamic changes associated with portal hypertension, including the hyperdynamic state, portosystemic shunts, and splanchnic vasodilation, cause significant disturbances in the pulmonary vasculature and play a key role in the pathogenesis of the disease. Without treatment, portopulmonary hypertension leads to progressive right ventricular failure with a poor prognosis. Although Doppler echocardiography is the best initial screening tool for symptomatic patients and candidates for liver transplant, right heart catheterization remains the gold standard for disease diagnosis. Treatment of patients with portopulmonary hypertension is aimed at improving cardiac function, reducing pulmonary vascular resistance, and optimizing functional capacity. Pulmonary hypertension-specific therapy, which includes prostacyclin and its receptor agonists, endothelin receptor antagonists, phosphodiesterase inhibitors, and guanylate cyclase stimulators, plays a key role in the treatment of patients with portopulmonary hypertension. Small uncontrolled and recent single randomized controlled trials have reported promising results of vasodilator therapy in terms of clinical and hemodynamic improvement in patients, allowing certain patients to undergo liver transplantation. This review discusses the epidemiology, approach to diagnosis and treatment of patients with portopulmonary hypertension. We used MEDLINE database on the PubMed platform and the Cochrane library to search for literature sources using the keywords: portopulmonary hypertension, portal hypertension, pulmonary hypertension, liver cirrhosis, pulmonary complications.

The regional disparities in liver disease comorbidity among elderly Chinese based on a health ecological model: the China Health and Retirement Longitudinal Study

PURPOSE

This study aimed to investigate the risk factors for liver disease comorbidity among older adults in eastern, central, and western China, and explored binary, ternary and quaternary co-morbid co-causal patterns of liver disease within a health ecological model.

METHOD

Basic information from 9,763 older adults was analyzed using data from the China Health and Retirement Longitudinal Study (CHARLS). LASSO regression was employed to identify significant predictors in eastern, central, and western China. Patterns of liver disease comorbidity were studied using association rules, and spatial distribution was analyzed using a geographic information system. Furthermore, binary, ternary, and quaternary network diagrams were constructed to illustrate the relationships between liver disease comorbidity and co-causes.

RESULTS

Among the 9,763 elderly adults studied, 536 were found to have liver disease comorbidity, with binary or ternary comorbidity being the most prevalent. Provinces with a high prevalence of liver disease comorbidity were primarily concentrated in Inner Mongolia, Sichuan, and Henan. The most common comorbidity patterns identified were "liver-heart-metabolic", "liver-kidney", "liver-lung", and "liver-stomach-arthritic". In the eastern region, important combination patterns included "liver disease-metabolic disease", "liver disease-stomach disease", and "liver disease-arthritis", with the main influencing factors being sleep duration of less than 6 h, frequent drinking, female, and daily activity capability. In the central region, common combination patterns included "liver disease-heart disease", "liver disease-metabolic disease", and "liver disease-kidney disease", with the main influencing factors being an education level of primary school or below, marriage, having medical insurance, exercise, and no disabilities. In the western region, the main comorbidity patterns were "liver disease-chronic lung disease", "liver disease-stomach disease", "liver disease-heart disease", and "liver disease-arthritis", with the main influencing factors being general or poor health satisfaction, general or poor health condition, severe pain, and no disabilities.

CONCLUSION

The comorbidities associated with liver disease exhibit specific clustering patterns at both the overall and local levels. By analyzing the comorbidity patterns of liver diseases in different regions and establishing co-morbid co-causal patterns, this study offers a new perspective and scientific basis for the prevention and treatment of liver diseases.

Pulmonary Dysfunction in Patients with Cirrhosis of the Liver: A Study of Pulmonary Function Tests and Arterial Blood Gases

Background and Aim

Respiratory complications in liver cirrhosis can occur due to various mechanisms, such as ascites causing restricted lung expansion and opening of intrapulmonary vascular shunts due to high portal pressures. We aimed to study the effects of the liver dysfunction on the lungs by evaluating arterial blood gas (ABG) and pulmonary function test (PFT) of all study subjects.

Subjects and Methods

A cross-sectional study was done between August 2020 and September 2022. Diagnosed cases of the liver cirrhosis were enrolled in the study after informed consent and were subjected to the following investigations: chest X-ray, oximetry, spirometry, diffusing capacity of the lung for carbon monoxide (DLCO), two-dimensional echocardiography, and ABG analysis (ABGA). The cases were divided into three groups based on their Child-Pugh staging, and statistical analysis was done on the collected data.

Results

A total of 64 (53 males and 11 females) patients with an average age of 49.82 ± 9.89 years were studied. Alcoholism was the most common cause of cirrhosis in males. Breathlessness (65.6%) and pleural effusion (26.6%) were the most common respiratory symptoms and signs, respectively. Seventeen patients had hepatic hydrothorax, eight patients had hepatopulmonary syndrome (HPS), and six patients had portopulmonary hypertension. Low pH (17.2%) and oxygen partial pressure (PaO2) (20.3%) were the most common ABGA findings. The pH, PaO2, forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC), and DLCO were significantly low in Child Pugh Stage C (P < 0.05). The pH, pO2, HCO3, FEV1, FVC, FEV1/FVC, and DLCO were significantly lower in patients with HPS (P < 0.05).

Conclusion

Metabolic acidosis and low FEV1/FVC and DLCO were the common findings in study subjects. Pulmonary dysfunction was common in advanced liver cirrhosis. Patients with HPS had worse ABG and PFT parameters than those without HPS.

[Pulmonary Complications in Patients with Liver Cirrhosis]

Portal hypertension is a clinical syndrome defined by an increased portal venous pressure. The most frequent cause of portal hypertension is liver cirrhosis, and many of the complications of cirrhosis, such as ascites and gastroesophageal variceal bleeding, are related to portal hypertension. Portal hypertension is a pathological condition caused by the accumulation of blood flow in the portal system. This blood flow retention reduces the effective circulation volume. To compensate for these changes, neurotransmitter hormone changes and metabolic abnormalities occur, which cause complications in organs other than the liver. A hepatic hydrothorax is fluid accumulation in the pleural space resulting from increased portal pressure. Hepatopulmonary syndrome and portopulmonary hypertension are the pulmonary complications in cirrhosis by deforming the vascular structure. Symptoms, such as dyspnea and hypoxia, affect the survival and the quality of life of patients. These lung complications are usually underestimated in the management of cirrhosis. This review briefly introduces the type of lung complications of cirrhosis.

Imaging in hepatopulmonary syndrome-case report. A multicenter approach during the coronavirus pandemic

A 60-year-old lady with alcoholic liver disease developed central cyanosis and orthodeoxia. A technetium-99m macro-aggregated albumin lung perfusion scan and contrast echocardiogram were performed. A 13% right to left shunt was calculated from the macro-aggregated albumin scan. There were more bubbles in the left heart than the right at the end of the contrast echocardiogram. Hepatopulmonary syndrome was therefore diagnosed. The patient had a liver transplant five days after these investigations. Further discussion about hepatopulmonary syndrome will be provided. Normally, macro-aggregated albumin scans are performed in few centers, however as this was at the height of the coronavirus pandemic, the scan needed to be performed locally to reduce the chance of the patient getting coronavirus. Local radiographers were remotely instructed on conducting the macro-aggregated albumin scan by a larger center to provide a timely and important investigation in a logistically difficult scenario.

Portopulmonary Hypertension

PoPH is a well-recognized complication of portal hypertension with or without cirrhosis and is classified as a subset of PAH. Identification of PoPH is crucial as it has a major impact on prognosis and liver transplant candidacy. Echocardiogram is the initial screening tool of choice and the patient should proceed to RHC for confirmation. PAH-directed therapy is the treatment of choice, allowing the patient to achieve a hemodynamic threshold to undergo a liver transplant safely.

Unmasking Hypoxia in Cirrhosis Patients: Six-Minute Walk Test as a Screening Tool for Hepatopulmonary Syndrome

Background

Hepatopulmonary syndrome (HPS) is one of the complications of advanced cirrhosis which has a serious impact on prognosis of patient. Finding arterial deoxygenation early and initiating higher-level treatment is one of the most critical strategies in the therapy of HPS. In this study, we aimed to assess the utility of six-minute walk test (6MWT) in the diagnosis of HPS.

Materials and Methods

We have enrolled 100 consecutive cirrhosis patients referred to the Liver Clinic of a tertiary care centre of India for >1 year. The Child-Pugh score and the MELD score were used to determine the severity of cirrhosis. All the patients underwent transthoracic contrast echocardiography, arterial blood gas measurements on room air, 6MWT, and chest imaging.

Results

A total of 100 patients were included in the study after fulfilling the inclusion criteria. HPS was present in 21 out of 100 patients (21%). Median (twenty fifth to seventy fifth percentile) MELD score in patients with HPS was 29 (26-33), which was significantly higher as compared to patients without HPS 22 (14.5-26); P <.0001. The 6MWT was positive in 20 (95.23%) HPS patients, while only 1 patient (4.77%) of HPS had negative 6MWT. If 6MWT is positive, then there was 76.92% probability of HPS and if 6MWT is negative, then 98.65% chances of no HPS.

Conclusion

The 6MWT is a simple and effective screening test for HPS, it helps in identifying the patients early who have a potential to deteriorate. This simple intervention would help in prioritizing patients for liver transplantation as liver transplant is the only effective treatment for HPS.

Cardiac autonomic modulation in children with severe liver disease, before and after liver transplantation

BACKGROUND

The cardiovascular system is directly influenced by the autonomic nervous system (ANS); its changes affect heart rate variability (HRV) and are sensitive indicators of physiological changes. Autonomic dysfunction (AD) is manifested in up to 60% of patients with cirrhosis. Therefore, we aim to analyze the indexes of HRV pre- and post-surgery of children submitted for liver transplantation (LT).

METHODS

HRV, in children of both genders from 6 months of age to 10 years, that attended at the pediatric surgery clinic in the queue for LT at the Children's Institute were analyzed. To access HRV we analyzed indexes such as standard deviation of the RR intervals (SDNN), root-mean-square of the successive normal sinus RR interval difference (RMSSD), low frequency (LF), high frequency (HF), and LF/HF.

RESULTS

The analysis of the behavior of cardiac autonomic modulation, in the period prior to LT and after surgery, showed an increase in HRV linear parameters SDNN, TINN (triangular interpolation of NN interval histogram), HFms². In the time domain, there was also an increase in the HFms² index.

CONCLUSIONS

The analysis of the period preceding LT and two months after surgery showed an increase in the HRV linear parameters representing a global HRV improvement. In the time domain, there was also an increase in the HFms² index, parasympathetic tone of the HRV.

Cardiac and renal effects of liver cirrhosis in a growing animal model

PURPOSE

To assess the biochemical, histological, histomorphometric and molecular effects of biliary duct ligation (BDL) induced liver cirrhosis in the heart and kidneys.

METHODS

Thirty-two weaning rats (21 days old, 50-70 g) underwent BDL and were divided in four groups (euthanasia after two, four, six, and eight weeks, respectively) and compared to control groups.

RESULTS

The animals' hearts of group 3 were bigger than those of the control group (p=0.042), including thinner right ventricle wall, decreased internal diameter of ventricles, and increased perivascular collagen deposition in left ventricle, as well as increased interstitial collagen in right ventricle after six weeks. In the kidneys of groups 3 and 4, bilirubin impregnation in the tubules, hydropic degeneration, loss of nuclei and lack of plasmatic membrane limits were noted. Nitric oxide synthase (NOS) gene expressions were higher in group 1 (p=0.008), and endothelial nitric oxide synthase (eNOS) gene expressions were elevated in all experimental groups (p=0.008, p=0.001, p=0.022, and p=0.013, respectively). In the heart, a decreased expression of eNOS in group 1 (p=0.04) was observed.

CONCLUSIONS

Liver cirrhosis leads to histological and histomorphometric alterations in the heart and kidneys, with changes in the NOS and eNOS gene expressions, that may suggest a role in the associated myocardial and renal manifestations.

Assessment of biventricular function in patients with hepatopulmonary syndrome

Cardiac function impairment in the setting of hepatopulmonary syndrome (HPS) in patients with end stage liver disease remains an issue of debate. The current study evaluated possible correlations between HPS and biventricular systolic function in patients with decompensated cirrhosis. Consecutive liver transplantation candidates with stable decompensated cirrhosis were prospectively evaluated. HPS was defined as the presence of an elevated alveolar-arterial oxygen gradient and intrapulmonary vasodilatation, detected by contrast enhanced echocardiography. HPS severity was determined based on arterial blood oxygen pressure values, while shunt size was assessed with a semi-quantitative method. Demographic, clinical and laboratory parameters were also prospectively collected. In total, 130 patients (mean age 56.5, M/F: 94/36, MELD score 14.6 ± 5.6) were enrolled, of whom 45 (34.6%) fulfilled the criteria for HPS diagnosis (mild: 57.7%, moderate: 33.3%, severe 4.4% and very severe 4.4%). Significantly lower absolute left ventricular (LV) global longitudinal strain (GLS) values (- 21.6 ± 2.3 vs. - 22.6 ± 2.5%, p = 0.041) were measured in patients with HPS compared to cirrhotic patients without HPS, while there was no statistically significant difference regarding right ventricular GLS (- 22.1 ± 3.3 vs. - 23.2 ± 3.5%, p = 0.061) between the two groups. Lower LV ejection fraction values were also recorded in the HPS group (53.9 ± 3.5 vs. 56.3 ± 4.5%, p < 0.01). No other echocardiographic parameter was correlated to HPS. Intrapulmonary shunt grading was correlated to HPS classification (χ² = 19.8, p < 0.01), with lower arterial oxygen values being recorded in higher stages of intrapulmonary shunt. In patients with cirrhosis, the presence of HPS is associated with worse LV contractile performance.

Paddling Upstream With Point-of-Care Ultrasound to Diagnose Cardiac Ascites

Ascites has multiple etiologies, including cirrhosis and heart failure, which can be differentiated by point-of-care ultrasound (POCUS). One cause of cardiac ascites that can be difficult to identify is portopulmonary hypertension (PPH), a rare disorder caused by pulmonary artery vasoconstriction due to advanced liver disease. POCUS can readily identify right ventricular dysfunction which can accelerate a PPH diagnosis. This case report describes the use of POCUS to work-up new onset ascites and expedite diagnosis of cardiac ascites due to PPH.