Optimal management of hepatorenal syndrome in patients with cirrhosis

Extracorporeal liver support techniques: a comparison

ExtraCorporeal Liver Support (ECLS) systems were developed with the aim of supporting the liver in its detoxification function by clearing the blood from hepatic toxic molecules. We conducted a retrospective comparative analysis on patients presenting with liver failure who were treated with different extracorporeal techniques in our intensive care unit to evaluate and compare their detoxification abilities. To verify the effectiveness of the techniques, mass balance (MB) and adsorption per hour were calculated for total bilirubin (TB), direct bilirubin (DB), and bile acids (BA) from the concentrations measured. MB represents the total amount (mg or mcMol) of a molecule removed from a solution and is the only representative parameter to verify the purification effectiveness of one system as it is not affected by the continuous production of the molecules, released in the circulation from the tissues, as it is the case for the reduction rate (RR). The total adsorption per hour is calculated by the ratio between MB and the time duration and shows the adsorption ability in an hour. Our comparative study shows the superior adsorption capability of CytoSorb system regarding TB, DB, and BA, evaluated through the MB and adsorption per hour, in comparison with CPFA, MARS, Prometheus, and PAP. In conclusion, as extracorporeal purification in liver failure could be considered useful for therapeutic purposes, Cytosorb, being more performing than other systems considered, could represent the device of first choice.

[Hepatorenal Syndrome]

Hepatorenal syndrome (HRS) is a critical and potentially life-threatening complication of advanced liver disease, including cirrhosis. It is characterized by the development of renal dysfunction in the absence of underlying structural kidney pathology. The pathophysiology of HRS involves complex interactions between systemic and renal hemodynamics, neurohormonal imbalances, and the intricate role of vasoconstrictor substances. Understanding these mechanisms is crucial for the timely identification and management of HRS. The diagnosis of HRS is primarily clinical and relies on specific criteria that consider the exclusion of other causes of renal dysfunction. The management of HRS comprises two main approaches: vasoconstrictor therapy and albumin infusion, which aim to improve renal perfusion and mitigate the hyperdynamic circulation often seen in advanced liver disease. Additionally, strategies such as liver transplantation and renal replacement therapy are essential considerations based on individual patient characteristics and disease severity. This review article provides a comprehensive overview of hepatorenal syndrome, focusing on its pathophysiology, diagnostic criteria, and current management strategies.

Does Anemia Have a Potential Effect on Type 2 Hepatorenal Syndrome?

Background/Aims. Hepatorenal syndrome (HRS) is a form of functional renal failure arising in advanced cirrhosis and is characterized by a poor survival rate. Anemia is frequently observed during the clinical course of cirrhosis. Our study aimed to investigate the hematologic findings in patients with cirrhosis to determine the effects of anemia on renal functions in type 2 HRS and if it was a potential aggravating factor. Materials and Methods. This prospective study, in which all consecutive patients with cirrhosis were enrolled, was performed at a tertiary-level hospital (Military Hospital of Tunis) from January 2019 to June 2019. A total of 9 patients with HRS fulfilled the type 2 HRS diagnostic criteria, and 41 patients with cirrhosis without HRS were included. All data regarding patients were obtained from the medical record. Demographic data, routine hemograms, biochemical, and urinary test results were collected. Models of end-stage liver disease (MELD) and Child-Turcotte-Pugh (CTP) scores were calculated. Results. The most common etiology of cirrhosis was viral hepatitis (66%). According to the CTP score, 23 patients were in the CTP-A stage, 13 in the CTP-B stage, and 14 patients were in the CTP-C stage. Patients with type 2 HRS had significantly lower hemoglobin levels compared with non-HRS stable cirrhosis patients. As hemoglobin levels decreased, renal function worsened on patients with type 2 HRS. Patients with lower hemoglobin levels had poor prognosis and survival compared with patients with higher hemoglobin levels. Logistic regression analysis showed that lower hemoglobin levels and higher MELD and CTP scores were statistically significant for an onset of type 2 HRS. Conclusion. Renal dysfunction is a frequent complication in patients with end-stage chronic liver disease. The role of anemia in aggravating HRS in patients with cirrhosis is explained by hypoxia that can lead to microcirculatory renal ischemia. Other studies are required to determine if anemia is a precipitant factor for HRS or not.

Role of endotoxemia in causing renal dysfunction in cirrhosis

Renal failure is a challenging problem in patients with cirrhosis since mortality increases with worsening renal function, hence the inclusion of serum creatinine in calculating the Model for End-Stage Liver Disease score for liver transplant evaluation. Among the various causes, infection is the leading etiology of mortality associated with cirrhosis. Bacterial infection frequently precipitates renal failure in patients with cirrhosis with the reported prevalence around 34%. Patients with cirrhosis are at increased risk of infections due to impaired immunity and increased gut permeability leading to bacterial translocation in the setting of portal hypertension. One of the most feared complications of severely decompensated liver and renal failure is hepatorenal syndrome, of which liver transplant may be the only available treatment. Furthermore, in those with spontaneous bacterial peritonitis and urinary tract infection, progressive renal failure occurs despite resolution of infection. Thus, the effects of endotoxemia on renal function in cirrhosis have become a major focus of research. The mechanisms of the damaging effects of endotoxin on renal function are complex but, in essence, involve dysregulated inflammation, circulatory dysfunction, poor clearance of endotoxin burden, as well as vasomotor nephropathy. In this article, we will review the mechanisms of endotoxemia-induced renal dysfunction in the setting of cirrhosis through the effects on renal blood flow, renal vascular endothelium, glomerular filtration rate, and tubular function.

Hepatorenal syndrome: the clinical impact of vasoactive therapy

Hepatorenal syndrome (HRS) is a unique form of acute kidney injury seen in cirrhotic patients and associated with significant mortality and morbidity. Despite its impact, diagnosis and treatment of HRS remains challenging and this review aims to assess and compare the available vasoconstrictors used as first-line treatment for HRS. Areas covered: A literature review was undertaken on the use of vasoconstrictors in HRS, using PubMed/Medline database searches of: 'hepatorenal syndrome', 'HRS' and 'vasoconstrictor'. Expert commentary: Current diagnosis criteria are based on an exclusion-based approach using serum creatinine as a biomarker. However, this method relies on the measurement over a sustained period of time resulting in delayed treatment. Using urine biomarkers, the revised acute kidney injury guidelines and novel plasma expanders may improve diagnosis and the implementation of time-sensitive management of HRS. Vasoconstrictors are the first-line treatment for HRS, in which terlipressin is the vasoconstrictor of choice supported by current guidelines and a substantial clinical evidence base over other vasoconstrictors, such as noradrenaline or midodrine plus octreotide. Future developments in dosage and administrative techniques for terlipressin may have an important role to play in maintaining clinical efficacy whilst improving tolerability in the management of HRS.

Albumin treatment regimen for type 1 hepatorenal syndrome: a dose-response meta-analysis

BACKGROUND

Recommended treatment for type 1 hepatorenal syndrome consists of albumin and vasoconstrictor. The optimal albumin dose remains poorly characterized. This meta-analysis aimed to determine the impact of albumin dose on treatment outcomes.

METHODS

Clinical studies of type 1 hepatorenal syndrome treatment with albumin and vasoconstrictor were sought. Search terms included: hepatorenal syndrome; albumin; vasoconstrictor; terlipressin; midodrine; octreotide; noradrenaline; and norepinephrine. A meta-analysis was performed of hepatorenal syndrome reversal and survival in relation to albumin dose.

RESULTS

Nineteen clinical studies with 574 total patients were included, comprising 8 randomized controlled trials, 8 prospective studies and 3 retrospective studies. The pooled percentage of patients achieving hepatorenal syndrome reversal was 49.5% (95% confidence interval, 40.0-59.1%). Increments of 100 g in cumulative albumin dose were accompanied by significantly increased survival (hazard ratio, 1.15; 95% confidence interval, 1.02-1.31; p = 0.023). A non-significant increase of similar magnitude in hepatorenal syndrome reversal was also observed (odds ratio, 1.15; 95% confidence interval, 0.97-1.37; p = 0.10). Expected survival rates at 30 days among patients receiving cumulative albumin doses of 200, 400 and 600 g were 43.2% (95% confidence interval, 36.4-51.3%), 51.4% (95% confidence interval, 46.3-57.1%) and 59.0% (95% confidence interval, 51.9-67.2), respectively. Neither survival nor hepatorenal syndrome reversal was significantly affected by vasoconstrictor dose or type, treatment duration, age, baseline serum creatinine, bilirubin or albumin, baseline mean arterial pressure, or study design, size or time period.

CONCLUSIONS

This meta-analysis suggests a dose-response relationship between infused albumin and survival in patients with type 1 hepatorenal syndrome. The meta-analysis provides the best current evidence on the potential role of albumin dose selection in improving outcomes of treatment for type 1 HRS and furnishes guidance for the design of future dose-ranging studies.

Pathogenesis of solute-free water retention in experimental ascitic cirrhosis: is vasopressin the only culprit?

Catecholamines trigger proximal tubular fluid retention and reduce renal excretion of solute-free water. In advanced cirrhosis, non-osmotic hypersecretion of vasopressin (antidiuretic hormone or ADH) is considered the cause of dilutional hyponatraemia, but ADH V2 receptor antagonists are not beneficial in long-term treatment of ascites. To test the hypothesis that water retention in experimental ascitic cirrhosis might depend primarily on adrenergic hyper-function, hormonal status, renal function and tubular free-water reabsorption (TFWR) were assessed in six groups of rats with ascitic cirrhosis: rats with cirrhosis due to 13-week CCl4 (carbon tetrachloride) administration (group G1); cirrhotic rats receiving daily diuretics (0.5 mg/kg furosemide plus 2 mg/kg K(+)-canrenoate) from the 11th to the 13th week of CCl4 (G2), diuretics associated with guanfacine oral prodrug (α2A-adrenergic receptor agonist and sympatholytic agent) at 2 (G3), 7 (G4) or 10 (G5) mg/kg, or with SSP-004240F1 (V2 receptor antagonist) at 1 mg/kg (G6). Natriuresis was lower in G1 than in G2, G4 and G6 (all P<0.05). Guanfacine, added to diuretics (i.e. G3 compared with G2), reduced serum noradrenaline from 423±22 to 211±41 ng/l (P<0.05), plasma renin activity (PRA) from 35±8 to 9±2 ng/ml/h (P<0.05) and TFWR from 45±8 to 20±6 μl/min (P<0.01). TFWR correlated with plasma aldosterone (r=0.51, P<0.01) and urinary potassium excretion (r=0.90, P<0.001). In ascitic cirrhosis, reduced volaemia, use of diuretics (especially furosemide) and adrenergic hyper-function cause tubular retention of water. Suitable doses of sympatholytic agents are effective aquaretics.

Development of a rat model of D-galactosamine/lipopolysaccharide induced hepatorenal syndrome

AIM: To develop a practical and reproducible rat model of hepatorenal syndrome for further study of the pathophysiology of human hepatorenal syndrome.

METHODS: Sprague-Dawley rats were intravenously injected with D-galactosamine and lipopolysaccharide (LPS) via the tail vein to induce fulminant hepatic failure to develop a model of hepatorenal syndrome. Liver and kidney function tests and plasma cytokine levels were measured after D-galactosamine/LPS administration, and hepatic and renal pathology was studied. Glomerular filtration rate was detected in conscious rats using micro-osmotic pump technology with fluorescein isothiocyanate-labelled inulin as a surrogate marker.

RESULTS: Serum levels of biochemical indicators including liver and kidney function indexes and cytokines all significantly changed, especially at 12 h after D-galactosamine/LPS administration [alanine aminotransferase, 3389.5 ± 499.5 IU/L; blood urea nitrogen, 13.9 ± 1.3 mmol/L; Cr, 78.1 ± 2.9 μmol/L; K⁺, 6.1 ± 0.5 mmol/L; Na⁺, 130.9 ± 1.9 mmol/L; Cl^-, 90.2 ± 1.9 mmol/L; tumor necrosis factor-α, 1699.6 ± 599.1 pg/mL; endothelin-1, 95.9 ± 25.9 pg/mL; P < 0.05 compared with normal saline control group]. Hepatocyte necrosis was aggravated gradually, which was most significant at 12 h after treatment with D-galactosamine/LPS, and was characterized by massive hepatocyte necrosis, while the structures of glomeruli, proximal and distal tubules were normal. Glomerular filtration rate was significantly decreased to 30%-35% of the control group at 12 h after D-galactosamine/LPS administration [Glomerular filtration rate (GFR)₁, 0.79 ± 0.11 mL/min; GFR₂, 3.58 ± 0.49 mL/min·kgBW^-1; GFR₃, 0.39 ± 0.99 mL/min·gKW^-1]. The decreasing timing of GFR was consistent with that of the presence of hepatocyte necrosis and liver and kidney dysfunction.

CONCLUSION: The joint use of D-galactosamine and LPS can induce liver and kidney dysfunction and decline of glomerular filtration rate in rats which is a successful rat model of hepatorenal syndrome.

Treatment and management of ascites and hepatorenal syndrome: an update

Ascites and renal dysfunction are frequent complications experienced by patients with cirrhosis of the liver. Ascites is the pathologic accumulation of fluid in the peritoneal cavity, and is one of the cardinal signs of portal hypertension. The diagnostic evaluation of ascites involves assessment of its granulocyte count and protein concentration to exclude complications such as infection or malignoma and to allow risk stratification for the development of spontaneous peritonitis. Although sodium restriction and diuretics remain the cornerstone of the management of ascites, many patients require additional therapy when they become refractory to this treatment. In this situation, the treatment of choice is repeated large-volume paracentesis. Alteration in splanchnic hemodynamics is one of the most important changes underlying the development of ascites. Further splanchnic dilation leads to changes in systemic hemodynamics, activating vasopressor agents and leading to decreased renal perfusion. Small alterations in renal function influence the prognosis, which depends on the cause of renal failure. Prerenal failure is evident in about 70% of patients, whereas in about 30% of patients the cause is hepatorenal syndrome (HRS), which is associated with a worse prognosis. Therefore, effective therapy is of great clinical importance. Recent data indicate that use of the new definition of acute kidney injury facilitates the identification and treatment of patients with renal insufficiency more rapidly than use of the current criteria for HRS. In this review article, we evaluate approaches to the management of patients with ascites and HRS.

Hepatorenal syndrome

INTRODUCTION

Renal failure in cirrhosis is a common complication that is associated with poor survival. A rapid diagnosis of the cause of renal failure is mandatory because it is associated with prognosis.

AREAS COVERED

This review covers the differential diagnosis between hepatorenal syndrome (HRS) and other causes of renal failure, as well as the difficulty in making a correct diagnosis, caused by the differentiation between hepatorenal syndrome and acute tubular necrosis. This review also discusses the multifactorial mechanisms involved in the pathogenesis of HRS. The paper provides diagnostic algorithms to use in clinical practice, emphasized by the fact that some patients may have HRS superimposed on pre-existent renal failure.

EXPERT OPINION

The correct diagnosis of renal failure is essential to initiate the correct treatment of this complication. In patients with HRS type 1, treatment with vasopressin and albumin is the treatment of choice; however, 50% of patients do not respond to this treatment.