Pulmonary evaluation in pediatric liver transplant candidates

Pulmonary function testing in patients with liver cirrhosis (Review)

Liver cirrhosis is a common long-term outcome of chronic hepatic inflammation. Patients with liver cirrhosis may also have pulmonary complications. There are several reasons for pulmonary dysfunction in liver cirrhosis, including intrinsic cardiopulmonary dysfunction unrelated to liver disease and specific disorders related to the presence of liver cirrhosis and/or portal hypertension. The most prevalent and clinically significant pulmonary complications are hepatic hydrothorax, hepatopulmonary syndrome, spontaneous pulmonary empyema and portopulmonary hypertension. Pulmonary function tests (PFTs) have traditionally been used to assess the lung function of patients with liver cirrhosis. To the best of our knowledge, the present review is the first to detail all types of PFTs performed in patients with liver cirrhosis and discuss their clinical significance. Patients with liver cirrhosis have reduced values of spirometric parameters, diffusion capacity for carbon monoxide (DLCO), lung volumes, maximal inspiratory pressure and maximal expiratory pressure. Furthermore, they have a higher closing volume, a greater airway occlusion pressure 0.1 sec after the onset of inspiratory flow and greater exhaled nitric oxide values. In order to improve pulmonary function, patients with ascites may require therapeutic paracentesis. Such findings should be considered when evaluating individuals with liver disease, particularly those who may require surgery. Poor lung function, particularly restrictive lung disease, can have an impact on post-transplant outcomes, such as ventilator time, length of hospital duration and post-operative pulmonary complications; thus, the transplant care team needs to be aware of its prevalence and relevance.

Epidemiology of Digital Clubbing and Hypertrophic Osteoarthropathy: A Systematic Review and Meta-analysis

ABSTRACT

Digital clubbing and hypertrophic osteoarthropathy (HOA) are long-standing clinical entities, but their prevalence have not been synthesized. We aimed to estimate the prevalence of digital clubbing and HOA in people with existing medical conditions.We comprehensively searched PubMed, Embase, and Web of Science to select studies addressing HOA or digital clubbing and published through March 23, 2021. Summary estimates of the prevalence were derived through random-effects meta-analysis and narrative synthesis. The review protocol has been registered with PROSPERO, CRD42021243934.Of 3973 records, we included 142 studies. In adults, the pooled prevalence of digital clubbing was 33.4% (95% confidence interval [CI], 16.6-52.8), 31.3% (95% CI, 22.4-41.1), 27% (95% CI, 9.4-49.5), and 22.8% (95% CI, 10.8-37.6) in subjects with intestinal diseases, interstitial lung diseases, infective endocarditis, and hepatic diseases, respectively. In children and adolescents, the pooled prevalence of digital clubbing was 29.1% (95% CI, 19.4-39.9), 23% (95% CI, 9.0-41.1), 19.5% (95% CI, 4.1-42.4), and 17.1% (95% CI, 9.5-26.5) in subjects with human immunodeficiency virus infection, hemoglobinopathies, cystic fibrosis, and tuberculosis. The pooled prevalence of HOA was 10.1% (95% CI, 2.0-23.1) in adults with cancers, and 5% (95% CI, 2.5-8.2) in children and adolescents with cystic fibrosis.In conclusion, the prevalence of digital clubbing varied across disease groups in both adults and children. Full-spectrum HOA was mostly reported in adults with liver disease and cancers, and in children and adolescents with cystic fibrosis.

Natural history, risk factors, and outcome of hepatopulmonary syndrome in pediatric liver diseases

BACKGROUND

Limited pediatric literature is available regarding hepatopulmonary syndrome (HPS) especially in subjects with biliary atresia (BA) despite its proven prognostic significance. Thus, we aimed to study the natural history, risk factors, and outcome of HPS in BA and other chronic liver disease (CLD) subjects.

METHODS

All children (BA and other non-BA CLDs) older than 6 months of age were included in the study. HPS was diagnosed on the basis of standard international criteria. Also, fractional exhaled nitric oxide (FeNO) was measured at baseline.

RESULTS

During the study period from January 2017 to December 2018, there were 42 children in BA and 62 in the CLD group. The overall prevalence of HPS was 42.3%: 57.1% in the BA group and 32.2% in the CLD group. Median age at HPS diagnosis was 14.4 months and 90 months in the BA and non-BA CLD groups, respectively. By the end of study period, the prevalence of HPS in the BA group further increased to 73.8% at 0.7% per month. Lower serum albumin (p < 0.05) in BA and higher splenic Z scores (p 0.013) in other CLDs were found to be significant risk factors for HPS. FeNO measurement did not reach diagnostic significance.

CONCLUSION

Prevalence of HPS is higher and also develops at an earlier age in the BA group compared to other CLDs. Also, risk of HPS development increases with increasing disease duration in BA. Lower serum albumin in BA and higher splenic Z scores in other CLDs may predict risk for HPS development.

Prevalence and characteristics of hepatopulmonary syndrome in children with cirrhosis in southern Brazil

BACKGROUND

Hepatopulmonary syndrome (HPS) is defined as a triad characterized by arterial deoxygenation, intrapulmonary vascular dilatations (IPVDs), and liver disorder. The aims of this study were to assess the prevalence of HPS in children with cirrhosis, the clinical characteristics of patients with HPS, and the tests used for the diagnosis of IPVD.

PATIENTS AND METHODS

This was a prospective, cross-sectional study of 40 children with cirrhosis (median age: 44 months). Investigations of HPS included arterial blood gas analysis, contrast-enhanced transthoracic echocardiography (CE-TTE), and perfusion lung scanning using technetium-99m-labeled macroaggregated albumin (Tc-MMA). Patients' clinical characteristics (age, etiology of cirrhosis, and severity of hepatopathy) were assessed. HPS was defined as liver disease; alveolar-arterial oxygen gradient of at least 15 mmHg and/or partial pressure of arterial oxygen less than 80 mmHg; and detection of IPVD by CE-TTE or Tc-MMA scanning. Statistical significance was indicated by a P value less than 0.05.

RESULTS

The prevalence of HPS was 42.5% (17/40). Eight patients had moderate HPS (47%) and two patients had severe HPS (12%). In bivariate analysis, biliary atresia (P=0.033) and median age (10 months; P=0.005) were associated with HPS. In multivariate analysis, only age remained statistically significant (prevalence ratio=0.99; 95% confidence interval=0.98-0.99; P=0.010). Sixteen patients with HPS had IPVD detected by CE-TTE (94.1%) and six patients had IPVD detected by Tc-MMA scanning (35.3%), with no significant agreement between these methods (κ=-0.12; P=0.163).

CONCLUSION

HPS is a common complication of cirrhosis in children. A combination of clinical and imaging criteria should be used to diagnose HPS.

Pulse oximetry is insufficient for timely diagnosis of hepatopulmonary syndrome in children with liver cirrhosis

OBJECTIVE

To prospectively investigate the prevalence of hepatopulmonary syndrome (HPS), the importance of pulse oximetry in diagnosing HPS, and the longitudinal course after liver transplantation in children with cirrhosis referred for liver transplantation.

STUDY DESIGN

Fifty-six patients aged 1-17 years (mean age, 4.6 ± 5.0 years) with liver cirrhosis were screened for HPS by hyperemic capillary blood gas (CBG) analysis and contrast-enhanced transthoracic echocardiography. Eleven patients were excluded owing to conditions that can produce cardiopulmonary dysfunction, including 5 with cystic fibrosis, 1 with pulmonary arterial hypertension, and 5 with an intracardial shunt. HPS was classified in accordance with the European Respiratory Society Task Force criteria on pulmonary-hepatic disorders. Patient groups were compared for biochemical and clinical characteristics.

RESULTS

Eighteen children (40%) with cirrhosis were intrapulmonary vasodilatation (IPVD)-positive and had a pulse oximetry oxygen saturation level >98%. Two of these patients (11%) exhibited moderate HPS with an elevated alveolar arterial oxygen gradient >15 mm Hg and PaO2 <70 mm Hg; they died before undergoing liver transplantation. The sensitivity and specificity of CBG analysis for detecting elevated alveolar arterial oxygen gradient in children with IPVD was 94% and 53%, respectively. HPS was associated with late hepatoportoenterostomy (P < .04). Liver transplantation led to resolution of HPS in all patients.

CONCLUSION

IPVD is frequent in children with liver cirrhosis (40%). Pulse oximetry is insufficient for timely HPS diagnosis. Pathological CBG analysis data indicate IPVD in the majority of cases, but are imprecise in children aged <2 years. Contrast-enhanced transthoracic echocardiography and CBG analysis are recommended for evaluation of HPS in children with cirrhosis, regardless of liver synthesis capacity and clinical chemistry data.

Pharmacological treatment for hepatopulmonary syndrome

AIM

Hepatopulmonary syndrome is a pulmonary dysfunction in the context of liver cirrhosis characterized by arterial deoxygenation. Affected patients have increased morbidity and mortality, and many of them expire before undergoing liver transplantation. Therefore, finding medical therapy as a bridge to transplantation or as a final treatment is necessary. In this study, we aimed to review the current literature about pharmacological options available for treatment of hepatopulmonary syndrome.

METHODS

A PubMED and Scopus search was conducted in January 2013 on the English literature published in any time period to find human and animal studies reporting pharmacological therapy of hepatopulmonary syndrome.

RESULTS

Out of 451 studies, 29 relevant articles were included. The number of patients, type, dose, duration, and mechanism of drugs in these studies was extracted and summarized separately. Most of pharmacologic agents act through inhibition of nitric oxide synthase and reduction in nitric oxide production, inactivation of endothelin-1, and treatment of bacterial translocation and pulmonary angiogenesis.

CONCLUSION

Several drugs have been applied for the treatment of HPS with conflicting results. However, no large randomized trial has been conducted probably due to low number of patients. Multicentered clinical trials are necessary to investigate these drugs.