Pulmonary complications of cirrhosis

Point-of-Care Thoracic Ultrasonography in Patients With Cirrhosis and Liver Failure

Point-of-care ultrasonography (POCUS) helps determine liver-related pathologies like an abscess, portal vein or hepatic vein thromboses, presence of ascites, site for pleural or ascitic paracentesis, and guiding biopsies. POCUS is revolutionizing the management of critically ill patients presenting with pneumonia, acute respiratory distress syndrome, acute-on-chronic liver failure, and in the emergency. The objectives of thoracic ultrasonography (TUS) are to aid the clinician in differentiating between pneumonia, effusions, interstitial edema and collections, and in estimating the volume status of patients with liver disease using inferior vena cava dynamic indices. The use of POCUS in patients with cirrhosis has since evolved. It is now widely used to help diagnose volume status, left ventricular diastolic dysfunction, myocardial infarction, and right ventricular dilation due to pulmonary embolism and to determine the causes for weaning failures such as effusions, lung collapse, and pneumothorax. During the Coronavirus Disease 2019 (COVID-19) pandemic, moving patients for computed tomography can be difficult. Therefore, TUS is now essential in liver transplantation and intensive care practice to assess ventilatory pressures, cardiac function, and fluid management. This review indicates the current and optimized use of TUS, offers a practical guide on TUS in the liver intensive care unit (ICU), and presents a diagnostic pathway for determining lung and pleural pathology, resolution of respiratory failure, and aid weaning from mechanical ventilation.

Relative incidence and predictors of pulmonary arterial hypertension complicating type 2 diabetes: The Fremantle Diabetes Study Phase I

AIMS

To determine the relative incidence and predictors of pulmonary arterial hypertension (PAH) in type 2 diabetes.

METHODS

Hospitalizations for/with and death from/with PAH, and all-cause mortality, were ascertained from validated databases for participants from the longitudinal, community-based Fremantle Diabetes Study Phase I (FDS1; n = 1287) and age-, sex- and zip code-matched people without diabetes (n = 5153) between entry (1993-1996) and end-2017. Incidence rates (IRs) and IR ratios (IRRs) were calculated. Cox proportional hazards and competing risk models generated cause-specific (cs) and subdistribution (sd) hazard ratios (HRs) for incident PAH.

RESULTS

In the pooled cohort (mean age 64.0 years, 49% males), 49 (3.8%) of the type 2 diabetes participants and 133 (2.6%) of those without diabetes developed PAH during 106,556 person-years of follow-up (IRs (95% CI) 262 (194-346) and 151 (127-179) /100,000 person-years, respectively; IRR 1.73 (1.22-2.42), P = 0.001). Type 2 diabetes was associated with an unadjusted csHR of 1.97 (1.42-2.74) and sdHR of 1.44 (1.04-2.00) (P ≤ 0.03); after adjustment for age, sex, and co-morbidities, these were 1.43 (0.83-2.47) and 1.36 (0.97-1.91), respectively (P ≥ 0.07).

CONCLUSIONS

Type 2 diabetes is associated with an increased risk of PAH but this is no longer significant after adjustment for other explanatory variables and the competing risk of death.

Point-of-Care Echocardiography and Hemodynamic Monitoring in Cirrhosis and Acute-on-Chronic Liver Failure in the COVID-19 Era

Point-of-Care (POC) transthoracic echocardiography (TTE) is transforming the management of patients with cirrhosis presenting with septic shock, acute kidney injury, hepatorenal syndrome and acute-on-chronic liver failure (ACLF) by correctly assessing the hemodynamic and volume status at the bedside using combined echocardiography and POC ultrasound (POCUS). When POC TTE is performed by the hepatologist or intensivist in the intensive care unit (ICU), and interpreted remotely by a cardiologist, it can rule out cardiovascular conditions that may be contributing to undifferentiated shock, such as diastolic dysfunction, myocardial infarction, myocarditis, regional wall motion abnormalities and pulmonary embolism. The COVID-19 pandemic has led to a delay in seeking medical treatment, reduced invasive interventions and deferment in referrals leading to "collateral damage" in critically ill patients with liver disease. Thus, the use of telemedicine in the ICU (Tele-ICU) has integrated cardiology, intensive care, and hepatology practices across the spectrum of ICU, operating room, and transplant healthcare. Telecardiology tools have improved bedside diagnosis when introduced as part of COVID-19 care by remote supervision and interpretation of POCUS and echocardiographic data. In this review, we present the contemporary approach of using POC echocardiography and offer a practical guide for primary care hepatologists and gastroenterologists for cardiac assessment in critically ill patients with cirrhosis and ACLF. Evidenced based use of Tele-ICU can prevent delay in cardiac diagnosis, optimize safe use of expert resources and ensure timely care in the setting of critically ill cirrhosis, ACLF and liver transplantation in the COVID-19 era.

Pulmonary manifestations of chronic liver disease: a comprehensive review

Hepatopulmonary syndrome (HPS) and porto-pulmonary hypertension (PoPH) represent relatively common pulmonary vascular complications of advanced liver disease. Despite distinct differences in their pathogenetic background, both clinical states are characterized by impaired arterial oxygenation and limited functional status, and are associated with increased pre-transplantation mortality. Accumulation of ascitic fluid in the pleural cavity, known as hepatic hydrothorax (HH), is another frequent manifestation of decompensated cirrhosis, which may cause severe respiratory dysfunction, depending on the volume of the effusion, the rapidity of its development and its resistance to therapeutic measures. Orthotopic liver transplantation constitutes the only effective treatment able to resolve the pulmonary complications of liver disease. A prioritization policy for liver transplantation has evolved over the past years regarding advanced stages of HPS, yielding favorable outcomes regarding post-transplantation survival and HPS resolution. In contrast, severe PoPH is associated with poor post-transplantation survival. Hence, liver transplantation is recommended only for patients with PoPH and an acceptable reduction in pulmonary pressure values, after receiving PoPH-targeted vasodilating therapy. This review focuses on basic pathogenetic and diagnostic principles and discusses the current therapeutic approaches regarding HPS, PoPH, and HH.

Hepatic Hydrothorax

Hepatic hydrothorax (HH) is a pleural effusion that develops in a patient with cirrhosis and portal hypertension in the absence of cardiopulmonary disease. Although the development of HH remains incompletely understood, the most acceptable explanation is that the pleural effusion is a result of a direct passage of ascitic fluid into the pleural cavity through a defect in the diaphragm due to the raised abdominal pressure and the negative pressure within the pleural space. Patients with HH can be asymptomatic or present with pulmonary symptoms such as shortness of breath, cough, hypoxemia, or respiratory failure associated with large pleural effusions. The diagnosis is established clinically by finding a serous transudate after exclusion of cardiopulmonary disease and is confirmed by radionuclide imaging demonstrating communication between the peritoneal and pleural spaces when necessary. Spontaneous bacterial empyema is serious complication of HH, which manifest by increased pleural fluid neutrophils or a positive bacterial culture and will require antibiotic therapy. The mainstay of therapy of HH is sodium restriction and administration of diuretics. When medical therapy fails, the only definitive treatment is liver transplantation. Therapeutic thoracentesis, indwelling tunneled pleural catheters, transjugular intrahepatic portosystemic shunt and thoracoscopic repair of diaphragmatic defects with pleural sclerosis can provide symptomatic relief, but the morbidity and mortality is high in these extremely ill patients.

Review article: Update on current and emergent data on hepatopulmonary syndrome

Hepatopulmonary syndrome (HPS) is a frequent pulmonary complication of end-stage liver disease, characterized by impaired arterial oxygenation induced by intrapulmonary vascular dilatation. Its prevalence ranges from 4% to 47% in patients with cirrhosis due to the different diagnostic criteria applied among different studies. Nitric oxide overproduction and angiogenesis seem to be the hallmarks of a complicated pathogenetic mechanism, leading to intrapulmonary shunting and ventilation-perfusion mismatch. A classification of HPS according to the severity of hypoxemia has been suggested. Contrast-enhanced echocardiography represents the gold standard method for the detection of intrapulmonary vascular dilatations which is required, in combination with an elevated alveolar arterial gradient to set the diagnosis. The only effective treatment which can modify the syndrome’s natural history is liver transplantation. Although it is usually asymptomatic, HPS imparts a high risk of pretransplantation mortality, independently of the severity of liver disease, while there is variable data concerning survival rates after liver transplantation. The potential of myocardial involvement in the setting of HPS has also gained increasing interest in recent research. The aim of this review is to critically approach the existing literature of HPS and emphasize unclear points that remain to be unraveled by future research.

Respiratory Complication in Liver Disease

Cirrhosis, the twelfth leading cause of death, accounts for 1.1% of all deaths in the United States. Although there are multiple pulmonary complications associated with liver disease, the most important complications that cause significant morbidity and mortality are hepatopulmonary syndrome, hepatic hydrothorax, and portopulmonary hypertension. Patients with cirrhosis who complain of dyspnea should be evaluated for these complications. This article reviews these complications.

Hepatopulmonary syndrome is associated with the presence of hepatocellular carcinoma in patients with decompensated cirrhosis

Background

Hepatopulmonary syndrome (HPS) is a relatively common complication in patients with decompensated cirrhosis. Our aim was to evaluate the prevalence of HPS, its clinical impact, and the possible association between HPS and characteristics of patients with decompensated cirrhosis.

Methods

Patients with stable decompensated cirrhosis admitted to our department and assessed for HPS were included. For each patient, several clinical, laboratory and echocardiographic parameters as well as renal function were recorded. The severity of liver disease was evaluated according to the Model for End-stage Liver Disease and Child-Pugh scores, and renal function was assessed using ⁵¹chromium complexed with ethylene diamine tetracetic acid. In addition, the short synacthen test was performed in each patient to evaluate the adrenal function.

Results

Sixty-three patients were enrolled, 26 (41.3%) of whom diagnosed with HPS. In multivariate analysis, the presence of hepatocellular carcinoma [odds ratio (OR) 8.1, 95% confidence interval (CI) 5.3-27.9, P=0.045] and salivary cortisol at T60 (60 min after the intravenous injection of 250 μg corticotropin) (OR 0.88, 95%CI 0.71-0.98, P=0.045) were the factors independently associated with HPS. T60 salivary cortisol had relatively good discriminative ability for the presence of HPS (area under the curve=0.73). The presence of HPS was not associated with the outcome (P=0.22).

Conclusion

In our cohort of patients with decompensated cirrhosis, the presence of hepatocellular carcinoma and T60 salivary cortisol were the only factors independently associated with HPS.

Hepatic hydrothorax: clinical review and update on consensus guidelines

Hepatic Hydrothorax (HH) is defined as a pleural effusion greater than 500 ml in association with cirrhosis and portal hypertension. It is an uncommon complication of cirrhosis, most frequently seen in association with decompensated liver disease. The development of HH remains incompletely understood and involves a complex pathophysiological process with the most acceptable explanation being the passage of the ascetic fluid through small diaphragmatic defects. Given the limited capacity of the pleural space, even the modest pleural effusion can result in significant respiratory symptoms. The diagnosis of HH should be suspected in any patient with established cirrhosis and portal hypertension presenting with unilateral pleural effusion especially on the right side. Diagnostic thoracentesis should be performed in all patients with suspected HH to confirm the diagnosis and rule out infection and alternative diagnoses. Spontaneous bacterial empyema and spontaneous bacterial pleuritis can complicate HH and increase morbidity and mortality. HH can be difficult to treat and in our review below we will list the therapeutic modalities awaiting the evaluation for the only definitive therapy, which is liver transplantation.

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.

Hepatopulmonary Syndrome and Liver Transplantation: A Recent Review of the Literature

A severe and common pulmonary vascular complication of liver disease is hepatopulmonary syndrome (HPS). It is a triad of liver dysfunction and/or portal hypertension, intrapulmonary vascular dilatations, and increased alveolar-arterial oxygen gradient. Prevalence varies according to various study groups from 4%-47%. While the most common presenting symptom of HPS is dyspnea, it is usually asymptomatic, and thus all liver transplant candidates should be screened for its presence. Pulse oximetry is a useful screening method, but arterial blood gas examination is the gold standard. If there is an abnormal P (A-a)O2 gradient, microbubble transthoracic echocardiography should be done for diagnosis. Outcome is unpredictable, and there is currently no effective medical therapy. The only effective therapy is considered to be liver transplantation. Complete resolution of HPS after liver transplantation is seen within a year in most HPS patients.

Mechanical characteristics of the pulmonary artery in beagle dogs with hepatopulmonary syndrome and portopulmonary hypertension

The continuous changes in pulmonary hemodynamic properties in hepatopulmonary syndrome (HPS) and portopulmonary hypertension (PoPH) have not been fully characterized in large animal models of HPS and PoPH. Beagle dog models of HPS and PoPH were induced by chronic common bile duct ligation and Sephadex microspheres, respectively. The model was validated by catheter examination and pathological analyses, and the hemodynamic characteristics of the models were observed. The results revealed that the cross-sectional area of the blood vessel was significantly increased in HPS models, but it was significantly decreased in the PoPH models. Furthermore, the resistance of pulmonary circulation was elevated in models of HPS, but it was decreased in models of PoPH. The present findings renew the traditional view that pulmonary hypertension is due to the enhanced peripheral resistance.

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.

Role of angiogenic factors/cell adhesion markers in serum of cirrhotic patients with hepatopulmonary syndrome

BACKGROUND & AIMS

Hepatopulmonary syndrome is a complication of chronic liver disease resulting in increased morbidity and mortality. It is caused by intrapulmonary vascular dilations and arteriovenous connections with devastating influence on gas exchange. The pathogenesis is not completely understood but evidence mounts for angiogenesis. Aims of this study were to identify angiogenic factors in serum of patients with hepatopulmonary syndrome and to study the possibility to predict its presence by these factors.

METHODS

Multiplex assays were used to measure the concentration of angiogenic factors in patients with (n = 30) and without hepatopulmonary syndrome (n = 30). Diagnosis was based on the presence of gas exchange abnormality and intrapulmonary vasodilations according to published guidelines.

RESULTS

Patients with and without hepatopulmonary syndrome had similar MELD scores (median: 11.2 vs. 11.6; P = 0.7), Child-Pugh score (P = 0.7) and PaCO2 values (median: 35 vs. 37; P = 0.06). PaO2 and P(A-a) O2 gradient were significantly different (respectively median of 80 vs. 86, P = 0.02; and 24 vs. 16, P = 0.004). Based on area under the curve (AUC) data and P-values, the best predictors were vascular cell adhesion molecule 1 (VCAM1) (AUC = 0.932; P < 0.001) and intercellular adhesion molecule 3 (ICAM3) (AUC = 0.741; P = 0.003). Combining these factors results in an AUC of 0.99 (after cross-validation still 0.99).

CONCLUSIONS

VCAM1 and ICAM3 might be promising biomarkers for predicting hepatopulmonary syndrome. Combining these factors results in an AUC of 0.99 and a negative predictive value of 100%. Determining the concentration of these biomarkers might be a screening method to detect hepatopulmonary syndrome. The use of these biomarkers should be validated in larger groups of patients.

Living-donor liver transplantation for congenital biliary atresia with porto-pulmonary hypertension and moderate or severe pulmonary arterial hypertension: Kyoto University experience

Porto-pulmonary hypertension with moderate or severe pulmonary arterial hypertension (PAH) is viewed as a contraindication to liver transplantation (LT) because of associated poor outcomes; however, patients with biliary atresia (BA) are generally good candidates for LT. Ten patients with moderate/severe PAH underwent living-donor liver transplantation (LDLT) at our institution; eight of these patients had BA and were the focus of this study. Preoperative therapies, including prostaglandin (PG)I2 , were introduced. When mean pulmonary arterial pressure (mPAP) after treatment was <40 mmHg or initial mPAP without therapy was <35 mmHg, we performed an acute volume challenge test to evaluate right ventricular function. LDLT was performed when mPAP after anesthetic induction was confirmed at ≤35 mmHg. Six patients had favorable responses to preoperative treatment and catheter testing, but two patients showed poor responses. The two patients with poor responses had poor clinical courses with unstable mPAP after LDLT. The other six patients had successful courses with well-controlled mPAP, and PGI2 was withdrawn or weaned following LDLT. Survival did not significantly differ between the eight BA recipients with moderate/severe PAH and 77 age-matched BA recipients without PAH from the same time period. LDLT has major benefits for BA patients with well-controlled PAH.

Transition from hepatopulmonary syndrome to portopulmonary hypertension: a case series of 3 patients

Hepatopulmonary syndrome (HPS) and portopulmonary hypertension (PPHTN) are the two major pulmonary vascular complications of liver disease. While HPS is characterized by low pulmonary vascular resistance, PPHTN is defined by the presence of elevated pulmonary vascular resistance. Given these seemingly opposing pathophysiologic mechanisms, these conditions were traditionally felt to be mutually exclusive. In this series, we present three patients with severe hepatopulmonary syndrome who had spontaneous resolution of their HPS with the subsequent development of PPHTN. To our knowledge, this is the largest case series presented of this phenomenon in nontransplanted patients. One proposed mechanism for the occurrence of this phenomenon involves dysregulation of the same vascular signaling pathway, which may lead to both pulmonary vascular dilatations and pulmonary arterial remodeling in the same patient. Another theory involves the possible differential binding of endothelin-1, a vasoactive signaling peptide that induces vasoconstriction when bound to receptor A and vasodilation when bound to receptor B. Although the mechanisms for this phenomenon remain unclear, it is important to be vigilant of this phenomenon as it may change the patient's overall treatment plan, especially in regard to appropriateness and timing of liver transplant.

The effects of flavanoid on the treatment of hepatopulmonary syndrome

Purpose

Hepatopulmonary syndrome is an arterial oxygenation disorder brought about by advanced liver failure and pulmonary vascular dilatations. The reason why hypoxia develops in hepatopulmonary syndrome depends on the broadening of perialveolar capillary veins. Our study aims to investigate the effects of Flavanoid on hepatopulmonary syndrome through its inhibition of nitric oxide.

Methods

Three groups, each having 8 rats, were formed within the scope of our study. Group I (the control group) only received laparatomy, group II received choledoch ligation, and group III was administered Flavanoid (90% flavonoid diosmin, 10% flavonoid hesperidin) following choledoch ligation. The rats were administered Flavanoid at week two following choledoch ligation. The rats' livers and lungs were examined histopathologically following a five-week follow-up and the perialveolar vein diameters were measured. Arterial blood gases and biochemical parameters were evaluated.

Results

It was seen that fibrosis and oxidative damage in the liver with obstructive jaundice as well as hypoxia with pulmonary perialveolar vein sizes were significantly lower than the other group with cirrhosis formed through the administration of Flavanoid.

Conclusion

We have concluded that Flavanoid administration might be useful in the treatment of hypoxia in hepatopulmonary syndrome and the delay of cirrhosis contraction.

A 62-year-old female patient with left-sided pleural effusion

Hepatic hydrothorax is defined as a pleural effusion in patients with liver cirrhosis without primary cardiac, pulmonary or pleural disease. It is a rare but important cause of unilateral-pleural effusion. The prevalence of this complication is 5-10% of the total number of patients with advanced stages of cirrhosis. In most cases (85%), the effusion is right-sided; however, in 13% of cases it can be left-sided and bilateral in 2% of the cases. We present a case of left-sided hepatic hydrothorax in the absence of ascites in a patient with primary biliary cirrhosis. The diagnosis of cirrhosis was confirmed by the biopsy;the patient didn't have any history or any signs or symptoms of cirrhosis prior to her presentation. In the case described, the patient was treated with spirnolactone, furosemide and ursodeoxycholic acid. At follow-up after six months since the diagnosis, she was responding to treatment with no complications. This case emphasizes the importance of considering hepatic hydrothorax as an etiology of a transudative pleural effusion regardless of the presence or absence of ascites inpatients with occult cirrhosis.

Echocardiography for the detection of portopulmonary hypertension in liver transplant candidates: an analysis of cutoff values

Portopulmonary hypertension (POPH), a complication of chronic liver disease, may be a contraindication to liver transplantation (LT) because of the elevated risk of peritransplant and posttransplant morbidity and mortality. Because POPH is frequently asymptomatic, screening with echocardiography is recommended. The only reliable technique, however, for diagnosing POPH is right heart catheterization (RHC). The aims of this study were to evaluate the current estimated systolic pulmonary artery pressure (sPAP) cutoff value of 30 mm Hg and to determine a better cutoff value. One hundred fifty-two patients underwent pretransplant echocardiography between January 2005 and December 2010. These echocardiographic results were compared with pulmonary artery pressures measured during the pretransplant workup or at the beginning of the transplantation procedure (both by catheterization). With a cutoff value of 30 mm Hg, 74 of the 152 patients met the criteria for POPH on echocardiography, although the diagnosis was confirmed in only 7 patients during catheterization; this resulted in a specificity of 54%. It would have been more accurate to use a cutoff value of 38 mm Hg, which had a maximal specificity of 82% and, at the same time, guaranteed a sensitivity and negative predictive value of 100%. With the incorporation of the presence or absence of right ventricular dilatation, the specificity even increased to 93% for this new cutoff value. In conclusion, the prevalence of POPH was 4.6% among LT candidates in this study. We can recommend that LT candidates with an sPAP > 38 mm Hg should be referred for RHC. With the cutoff value increased from 30 to 38 mm Hg, the number of patients undergoing invasive RHC during their evaluation could be safely reduced.

Living-donor liver transplantation for moderate or severe porto-pulmonary hypertension accompanied by pulmonary arterial hypertension: a single-centre experience over 2 decades in Japan

BACKGROUND

Candidates for orthotopic liver transplantation (OLT) often have porto-pulmonary hypertension (PPHTN) with pulmonary arterial hypertension (PAH). Poor outcomes of PPHTN contraindicate OLT. There are no guidelines for living-donor liver transplantation (LDLT) in PPHTN patients.

METHODS

We present our experiences of LDLT in six patients with moderate or severe PPHTN, along with our institutional guidelines. Three had liver cirrhosis and three were non-cirrhotic. Catheterization studies were undertaken before, during and after LDLT, and the mean pulmonary arterial pressure (mPAP), cardiac output (CO), pulmonary vascular resistance and total peripheral resistance (TPR) were monitored.

RESULTS

The results showed significant differences in CO and TPR between cirrhotic and non-cirrhotic patients before, during and after LDLT. Cirrhotic patients showed systemic hyperdynamic state. Two cirrhotic patients showed poor responses to pre-transplant treatment, and continued to have increased PAH and poor clinical courses after LDLT. LDLT has an advantage of flexible timing of LT. Currently in our institution, PPHTN patients with mPAP <40 mmHg are registered for LDLT after treatment and catheterization. However, LDLT is performed when mPAP is ≤35 mmHg, leading to improved outcomes.

CONCLUSION

PPHTN patients with well-controlled PAH, or secondary PAH resulting from porto-systemic shunts, may be appropriate candidates for LDLT after careful considerations.

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.

TNF-α neutralization improves experimental hepatopulmonary syndrome in rats

BACKGROUND/AIM

TNF-α is increased in hepatopulmonary syndrome (HPS). Pentoxifylline (PTX) mitigated experimental HPS through the inhibition of TNF-α. However, PTX has pleiotropic effects besides the inhibition of TNF-α. This study is to neutralize TNF-α with specific monoclonal antibody to TNF-α (TNF-α McAb) to investigate the effect of TNF-α on HPS.

MATERIALS AND METHODS

Hepatopulmonary syndrome was induced by common bile duct ligation (CBDL); controls were sham operated. The endpoints were 1, 2, 3, 4 and 5 weeks after surgery. (99m) Technetium-macroaggregated albumin (Tc-MAA) was to evaluate intrapulmonary arteriovenous shunts; Portal venous pressure, cardiac output and mean blood pressure (MAP) were also measured. Serum was for Alanine transaminase (ALT), endotoxin, TNF-α and nitric oxide (NO) measurements, liver for histology, lung for histology and iNOS, PI3K/Akt expression assay.

RESULTS

Portal vein pressure was significantly elevated and MAP decreased in CBDL rats. Tc-MAA was mainly located in lung and very weak in brain in sham group and mainly in brain of CBDL rats. TNF-α McAb significantly decreased the radioactivity in the brain, reduced cardiac output, increased MAP and systemic vascular resistance (SVR) in CBDL animals. Serum ALT, endotoxin, TNF-α and NO were significantly increased. TNF-α McAb significantly decreased these serum indices in CBDL rats. TNF-α McAb significantly alleviated liver damage, decreased alveolar-arterial gradient and inhibited iNOS, PI3K/Akt and p-Akt expression in lung tissue. Furthermore, TNF-α McAb significantly attenuated the inflammatory response in lung.

CONCLUSION

TNF-α McAb improves HPS in cirrhotic rats; this effect is likely mediated through the inhibition of TNF-α PI3K/Akt-NO pathway.

Portal hypertension: pathophysiology, diagnosis, and treatment

Portal hypertension (PH) is the result of increased vascular resistance in the portal circulation, increased portal venous blood flow, or both. In veterinary medicine, where portal pressure is seldom measured directly, the diagnosis of PH often is inferred from identification of associated complications including multiple acquired portosystemic shunts, ascites, and hepatic encephalopathy. Likewise, treatment of PH primarily is aimed at controlling these complications. The goal of this review is to provide an update on the pathophysiology, diagnosis, and treatment of PH. The review draws from information in the veterinary hepatology literature, reviews, and consensus statements in human hepatology and the literature on experimental models of PH.

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.