The hepatorenal syndrome

Hepatorenal syndrome in children: a review

Hepatorenal syndrome (HRS) occurs in patients with cirrhosis or fulminant hepatic failure and is a kind of pre-renal failure due to intense reduction of kidney perfusion induced by severe hepatic injury. While other causes of pre-renal acute kidney injury (AKI) respond to fluid infusion, HRS does not. HRS incidence is 5% in children with chronic liver conditions before liver transplantation. Type 1 HRS is an acute and rapidly progressive form that often develops after a precipitating factor, including gastrointestinal bleeding or spontaneous bacterial peritonitis, while type 2 is considered a slowly progressive form of kidney failure that often occurs spontaneously in chronic ascites settings. HRS pathogenesis is multifactorial. Cirrhosis causes portal hypertension; therefore, stasis and release of vasodilator substances occur in the hepatic vascular bed, leading to vasodilatation of splanchnic arteries and systemic hypotension. Many mechanisms seem to work together to cause this imbalance: splanchnic vasodilatation; vasoactive mediators; hyperdynamic circulation states and subsequent cardiac dysfunction; neuro-hormonal mechanisms; changes in sympathetic nervous system, renin-angiotensin system, and vasopressin. In patients with AKI and cirrhosis, fluid expansion therapy needs to be initiated as soon as possible and nephrotoxic drugs discontinued. Once HRS is diagnosed, pharmacological treatment with vasoconstrictors, mainly terlipressin plus albumin, should be initiated. If there is no response, other options can include surgical venous shunts and kidney replacement therapy. In this regard, extracorporeal liver support can be a bridge for liver transplantation, which remains as the ideal treatment. Further studies are necessary to investigate early biomarkers and alternative treatments for HRS.

Amphora algae with low-level ionizing radiation exposure ameliorate D-galactosamine-induced inflammatory impairment in rat kidney

d-Galactosamine (d-GalN) is a well-known toxin that causes many metabolic and morphological abnormalities resulting in advanced renal failure and liver damage. Occupational exposure to low-level ionizing radiation (<1 Gy) was shown to enhance cell protection via attenuating an established inflammatory process. The present study was therefore aimed to investigate the protective impact of Amphora coffaeiformis extract and low dose gamma radiation against d-GalN induced renal damage in rats. Forty-eight adult male Swiss albino rats were distributed equally into eight groups. The measurements included antioxidants activities (superoxide dismutase, catalase and glutathione peroxidase) as well as lipid peroxidation level in kidney tissue. Also, kidney function tests and inflammatory markers (tumor necrosis factor alpha and nuclear factor kappa-light-chain-enhancer of activated B cells) were measured. Additionally, relative quantification of kidney nuclear factor erythroid 2-related factor 2 (Nrf-2) gene was estimated. Histopathological examination was also performed in kidney tissue. The results revealed decreases in antioxidant activities and downregulation of Nrf-2 expression accompanied by increases in lipid peroxidation level, kidney function tests and inflammatory markers in d-GaIN group. The treatment with Amphora algal extract and low dose gamma radiation ameliorated the previous measurements which were harmony with histopathological findings. In conclusion, A coffaeiformis extract and low dose gamma radiation provided marked functional and histological effects in the treating acute renal damage induced by d-GalN in rats.

Renal Dysfunction in Cirrhosis: Critical Care Management

Cirrhotic patients with manifestations of the end-stage liver disease have a high risk for developing renal dysfunction even with minor insults. The development of renal dysfunction increases the morbidity and mortality of these patients. Causes of renal dysfunction in cirrhotics can be due to hepatorenal syndrome (HRS) or acute kidney injury (AKI) resulting from prerenal, renal, and postrenal causes. Development of pretransplant renal dysfunction has been shown to affect post-liver transplantation outcomes. Early detection and aggressive strategies for the prevention of further progression of renal dysfunction seem to decrease the morbidity and improve survival in this group of patients. This article aims to outline the pathogenesis of renal dysfunction in cirrhosis, etiological factors, and evaluation of renal dysfunction, strategies for aggressive therapy for renal dysfunction, the indications of renal replacement therapy (RRT) in this group of patients, and the various modalities of RRT with their merits and demerits. A thorough understanding of the pathogenesis, early detection, and aggressive corrective measures for AKI can prevent further progression. In conclusion, a good knowledge of treatment modalities available for renal dysfunction in cirrhosis and institution of timely interventions can significantly improve survival in this group of patients.

Prevalence and short-term outcome of hepatorenal syndrome: A 9-year experience in a high-complexity hospital in Colombia

BACKGROUND & AIMS

Hepatorenal syndrome is a rare entity that is part of the complications of liver cirrhosis in its more severe stages. Without treatment, its mortality rate increases significantly. Terlipressin is considered to be the therapy of choice until the need of a liver transplant. The aim is to determine its prevalence, define patients' characteristics, triggers and 90-day survival, according to the type of managements established.

METHOD

This was a retrospective cohort study conducted in Colombia. It included patients with cirrhosis and acute kidney injury who met hepatorenal syndrome criteria, reaching 28 patients from 2007 to 2015. Groups were categorized according the type of hepatorenal syndrome and treatment. Demographic and trigger factors were evaluated to characterize the population. Treatment outcomes with terlipressin vs norepinephrine were analyzed up to a 90-day survival, using log Rank test. Continuous variables needed Student's T and Mann Whitney's U tests and categorical variables, Chi2 test. A value of p <0.05 and a power of 85% was considered. The data was analyzed in the SPSS version 23 software.

RESULTS

117 patients with cirrhosis developed renal injury; of these 23.9% were diagnosed with Hepatorenal Syndrome (67.8% type1; 32.1% type2). The presence of ascites was 100% in HRS2 and 84% in HRS1 (p = 0.296). The main trigger in both types was paracentesis greater than 5 liters in the last 4 weeks (39.3%). In total, 35% of the patients received renal replacement therapy and 14% underwent a hepatic transplant. Type 1 was more frequent (63% received terlipressin; 21% norepinephrine). The total complete response was 36% (Type2 66.6% vs. Type1 18.7%) (p = 0.026). In contrast, the overall mortality was of 67.8% at 90-day of follow-up (89.4% Type1 vs. 22% Type2) (p = <0.001). We found a lower mortality rate in patients treated with terlipressin than treated with norepinephrine (p = 0.006).

CONCLUSION

There is scarce clinical and epidemiological information about this condition in Colombia. A significant difference between the two drugs cannot be stipulated due to the limitation in the sample size of our study. The general mortality at a 90-day follow-up was high, being higher in patients with HRS1. While the results of this study are suggestive of clinical information for HRS patients in the Colombian population, they should also be interpreted with caution, therefore further multicenter studies should be performed.

Noradrenaline for reverting hepatorenal syndrome: a prospective, observational, single-center study

Objective

To evaluate the effectiveness of noradrenaline for the treatment of hepatorenal syndrome (HRS).

Background

HRS represents the development of renal failure in cirrhotic patients. The standard treatment for HRS is terlipressin, which, as opposed to noradrenaline, is more expensive and less accessible in most tertiary care centers.

Patients and methods

Thirty consecutive patients with HRS type 1 received noradrenaline (1–4.0 mg/hour) and albumin for 14 days. The parameters recorded were: serum creatinine levels, creatinine clearance, mean arterial pressure (MAP), urine output, and serum sodium levels evaluated at baseline and on treatment days 1, 3, 7, and 14.

Results

Most patients achieved serum creatinine levels <1.5 mg/dL and were considered responders (22/30, 73%), whereas eight patients (27%) were nonresponders. At baseline, responders and nonresponders differed only regarding initial bilirubin levels and international normalized ratio values. Treatment duration was 7.5±3.2 days. Responders experienced a significant (p<0.05) decrease in serum creatinine levels (from 3.26±0.48 to 1.28±0.14 mg/dL), as well as a significant increase (p<0.05) in creatinine clearance (from 21±4.1 to 67.7±12.1 mL/min), urine output (from 583±41.1 to 1163±105 mL/day), MAP (from 79.2±2.94 to 93.9±2.34 mmHg), and serum sodium levels (from 125±2.01 to 132.3±1.39 mEq/L). In nonresponders, the MAP increased, but serum creatinine levels also increased, reflecting a decrease in creatinine clearance and urine output, with no significant change in serum sodium levels over the duration of the treatment.

Conclusion

In most patients, noradrenaline treatment induced systemic vasoconstriction resulting in HRS reversal, with acceptable safety, in agreement with previously reported outcomes of terlipressin treatment.

Recovery of Native Renal Function in Patients with Hepatorenal Syndrome Following Combined Liver and Kidney Transplant with Mercaptoacetyltriglycine-3 Renogram: Developing a Methodology

Many patients with hepatorenal syndrome (HRS) end up receiving a combined liver and kidney transplant (CKLT) with preservation of native kidneys, specially type 1 HRS since is characterizes by a very rapid deterioration of renal function. Eventually, most of the patients regain renal function, but it is unknown if this is due to the transplanted kidney, the recovery of native renal function, or both. The aim of this study is to evaluate if there is recovery of native renal function in patients with HRS following CKLT. 22 patients (16 men; 6 women) with history of HRS and status post CKLT were studied. Mercapto-acetyltriglycine-3 renograms in the anterior and posterior views with the three kidneys in the field of view were simultaneously acquired. The renograms were analyzed by creating regions of interest around the transplanted and native kidneys. Relative contribution to the renal function, clearance, and effective renal plasma flow for the transplanted and native kidneys were obtained. 1/22 (4.5%) patients presented with a very poor functioning transplanted kidney, in 15/22 (68%) cases the combined native renal function was markedly poorer than the transplanted renal function and in 6/22 (27%) native kidneys showed a contribution to the renal function similar to the transplanted kidney. In conclusion, our series show that around 32% of the HRS patients recovered their native renal function after CKLT. Identification of common factors that affect recovery of native renal function may help to avoid unnecessary renal transplants, significantly reducing morbidity and cost, while facilitating a reallocation of scarce donor resources.

Evaluation of acute kidney injury and its response to terlipressin in patients with acute-on-chronic liver failure

BACKGROUND & AIMS

Patients with acute-on-chronic liver failure (ACLF) have high mortality. Cirrhotics with acute kidney injury (AKI) have poor outcome but relevance of AKI and response to terlipressin in ACLF is not known.

METHODS

Consecutive ACLF patients with AKI at admission were compared with those without AKI (controls) for mortality at day 7, month 1 and 3, presence of hepatic encephalopathy (HE), spontaneous bacterial peritonitis (SBP) and acute variceal bleed (AVB). Patients were also compared based on severity of AKI (mild; S.cr 1.5-3 mg/dl and marked; S.cr >3 mg/dl). Response to terlipressin was also evaluated.

RESULTS

Of 241 ACLF patients, 55 (22.8%) had AKI at admission. Patients with AKI had higher mortality at day 7, 1 and 3 month and more often developed HE [54.1% vs. 30.6%; P = 0.001] and SBP [9.1% vs. 5.9%; P = 0.02]. Patients with marked AKI neither had higher mortality or complications in comparison to mild AKI. Presence of AKI [Odds ratio; OR, 2.4], S.bilirubin >20 mg/dl [OR, 3.1] and INR [OR, 2.9] were independent baseline predictors of mortality. Terlipressin was used in 28 of 55 patients with AKI who were volume non-responsive (hepatorenal syndrome, AKI-HRS). Ten (35.7%) of these showed response (S.Cr < 1.5 mg/dl) [median 4 days] and had lower mortality compared to terlipressin non-responders (10% vs. 50%, P = 0.05). There was no difference in terlipressin response in mild vs. marked AKI.

CONCLUSIONS

Almost one-fourth of the ACLF patients have AKI at admission and presence of AKI, but not its severity predicts complications and high mortality. Terlipressin effectively reverses AKI-HRS within a week in ~35% of ACLF patients resulting in improved survival.

D-Galactosamine Intoxication in Experimental Animals: Is it Only an Experimental Model of Acute Liver Failure?

BACKGROUND

Short-term administration of Galactosamine to experimental animals causes liver damage and acute liver failure (ALF), as well as acute renal failure in some cases. The aim of our study was to describe kidney disorders that developed in the course of galactosamine-induced liver failure.

MATERIAL AND METHODS

Sprague-Dawley rats were randomly divided into 2 groups: a study group administered galactosamine intraperitoneally and a control group administered saline.

RESULTS

All the animals in the study group developed liver damage and failure within 48 h, with significant increase of alanine (p<0.001), aspartate aminotransferases (p<0.0001), bilirubin (p<0.004), and ammonia (p<0.005) and decrease of albumin (p<0.001) concentrations. Acute renal failure was observed in all test animals, with a significant increase in creatinine (p<0.001) and urea (p<0.001) concentrations and a decrease in creatinine clearance (p<0.0012). Moreover, osmotic clearance (p<0.001), daily natriuresis (p<0.003), and fractional sodium excretion (p<0.016) decreased significantly in this group of animals. The ratio of urine osmolality to serum osmolality did not change. Histopathology of the liver revealed massive necrosis of hepatocytes, whereas renal histopathology showed no changes.

CONCLUSIONS

Acute renal failure that developed in the course of galactosamine-induced ALF was of a functional nature, with the kidneys retaining the ability to concentrate urine and retain sodium, and there were no renal changes in the histopathological examination. It seems that the experimental model of ALF induced by galactosamine can be viewed as a model of hepatorenal syndrome that occurs in the course of acute damage and liver failure.

Hepatorenal syndrome: aetiology, diagnosis, and treatment

Acute renal impairment is common in patients with chronic liver disease, occurring in approximately 19% of hospitalised patients with cirrhosis. A variety of types of renal impairment are recognised. The most important of these is the hepatorenal syndrome, a functional renal impairment due to circulatory and neurohormonal abnormalities that underpin cirrhosis. It is one of the most severe complications of cirrhosis with survival often measured in weeks to months. A variety of treatment options exist with early diagnosis and appropriate treatment providing the best hope for cure. This paper provides a comprehensive and up-to-date review of hepatorenal syndrome and lays out the topic according to the following sections: pathophysiology, historical developments, diagnostic criteria and limitations, epidemiology, precipitating factors, predictors, clinical and laboratory findings, prognosis, treatment options, prophylaxis, and conclusion.

Advances in sepsis-associated liver dysfunction

Recent studies have revealed liver dysfunction as an early event in sepsis. Sepsis-associated liver dysfunction is mainly resulted from systemic or microcirculatory disturbances, spillovers of bacteria and endotoxin (lipopolysaccharide, LPS), and subsequent activation of inflammatory cytokines as well as mediators. Three main cell types of the liver which contribute to the hepatic response in sepsis are Kupffer cells (KCs), hepatocytes and liver sinusoidal endothelial cells (LSECs). In addition, activated neutrophils, which are also recruited to the liver and produce potentially destructive enzymes and oxygen-free radicals, may further enhance acute liver injury. The clinical manifestations of sepsis-associated liver dysfunction can roughly be divided into two categories: Hypoxic hepatitis and jaundice. The latter is much more frequent in the context of sepsis. Hepatic failure is traditionally considered as a late manifestation of sepsis-induced multiple organ dysfunction syndrome. To date, no specific therapeutics for sepsis-associated liver dysfunction are available. Treatment measure is mainly focused on eradication of the underlying infection and management for severe sepsis. A better understanding of the pathophysiology of liver response in sepsis may lead to further increase in survival rates.

Advances in the management of acute liver failure

Acute liver failure (ALF) is an uncommon but dramatic clinical syndrome characterized by hepatic encephalopathy and a bleeding tendency due to abrupt loss of liver function caused by massive or submassive liver necrosis in a patient with a previously healthy liver. The causes of ALF encompass a wide variety of toxic, viral, metabolic, vascular and autoimmune insults to the liver, and identifying the correct cause can be difficult or even impossible. Many patients with ALF develop a cascade of serious complications involving almost every organ system, and death is mostly due to multi-organ failure, hemorrhage, infection, and intracranial hypertension. Fortunately, the outcome of ALF has been improved in the last 3 decades through the specific treatment for the disease of certain etiology, and the advanced intensive care management. For most severely affected patients who fail to recover after treatment, rapid evaluation for transfer to a transplantation center and consideration for liver transplantation is mandatory so that transplantation can be applied before contraindications develop. This review focuses on the recent advances in the understanding of various contributing etiologies, the administration of etiology-specific treatment to alleviate the liver injury, and the management of complications (e.g., encephalopathy, coagulopathy, cardiovascular instability, respiratory failure, renal failure, sepsis and metabolic disturbance) in patients with ALF. Assessment of the need for liver transplantation is also presented.

Management of acute kidney injury in cirrhosis

Acute kidney injury (AKI) is a relatively frequent problem, occurring in approximately 20 % of hospitalized patients with cirrhosis. Although serum creatinine (S Cr) is the most commonly used method to determine AKI because of easy availability and low cost, practically it underestimates the extent of kidney injury in patients with chronic liver disease. AKI is defined as an abrupt rise in S Cr of 0.3 mg/dl or more (>26.4 mmol/l) or an increase of 150 % or more (1.5-fold) from baseline. The cause of AKI in cirrhosis is multifactorial and is unique in terms of pathogenesis. The most common causes of AKI in cirrhosis can be subdivided into either functional or structural. The functional group includes volume-responsive (prerenal azotemia) and volume-unresponsive states (hepatorenal syndrome). Volume responsive is the most common type of AKI due to frequent use of diuretics, large volume abdominal paracentesis and gastrointestinal bleeding in patients with liver disease. The structural causes include acute tubular necrosis, tubulointerstitial and glomerular diseases. Patients with decompensated cirrhosis are in a vasodilatory state leading to a decrease in effective arterial blood volume, predisposing to AKI. Therefore, management of AKI depends on the underlying cause, and therapy should be directed toward removal of the cause. The outcome in cirrhosis when patients are on dialysis is very dismal. Every effort should be made to prevent AKI.

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.

Advances in treatment of HBV-related liver failure with nucleoside analogues

Hepatitis B virus (HBV) infection is a common cause of liver failure in China. The mortality of fulminant hepatitis B is more than 70%. Adoption of antiviral therapy or not on the basis of comprehensive treatment has become a hot topic of recent research of treatment of fulminant hepatitis B, which causes liver failure in a way different from other reasons. HBV replication plays a critical role in initiating the development of fulminant hepatitis B. Reducing viral load to alleviate excessive immune response by antiviral therapy represents a new idea for the treatment of fulminant hepatitis B. The advent of nucleoside analogues makes it possible to conduct antiviral therapy against fulminant hepatitis B. This article summarizes recent advances in treatment of HBV-related liver failure with nucleoside analogues.

Hepatorenal syndrome: a comprehensive overview for the critical care nurse

Over the past 50 years, the pathophysiology and features of the hepatorenal syndrome have been illuminated. The syndrome can be divided into 2 distinct clinical patterns: a rapidly progressive renal failure with an extremely poor prognosis (type 1) and a slow progressive renal failure that correlates with the degree of cirrhosis (type 2). Although our understanding of hepatorenal syndrome continues to grow, our current methods of treating this condition remain limited in their effectiveness. The only definitive therapy is liver transplantation. This is a review of the definition, pathophysiology, and current recommendations for management of hepatorenal syndrome with the critical care nurse in mind.

Hepatorenal syndrome: beyond liver failure

Critical care nurses occasionally confront patient conditions that are not common. One such condition is hepatorenal syndrome (HRS). Three primary processes contribute to regional alterations in circulation in the renal and splanchnic beds. These processes include effective hypovolemia from the massive release of vasoactive mediators, thereby underfilling circulation, systemic and splanchnic vasodilation along with renal vasoconstriction, and hyperdynamic circulation. A "second-hit" hypothesis, whereby a triggering event causes intravascular volume depletion, likely initiates the development of HRS. The idea of a second hit focuses the attention of the health care team on surveillance strategies to prevent or limit HRS in patients with advanced cirrhosis and ascites. The treatment goal is to restore systemic and splanchnic vasoconstriction, while promoting renal vasodilation, balance sodium, and achieve euvolemia. The critical care nurse must maintain ongoing education to care for the patient with this complex syndrome in order to prevent complications and death.

Pig liver xenotransplantation as a bridge to allotransplantation: which patients might benefit?

Acute liver failure is a potentially devastating clinical syndrome that, without liver transplantation (Tx), is associated with high mortality. Rapid deterioration in clinical status and a shortage of deceased human organs prohibits liver Tx in many patients. Bridging to liver Tx has been attempted by various approaches, for example, bioartificial liver support, extracorporeal pig liver perfusion, and hepatocyte Tx, but none of these approaches has convincingly improved patient survival. The orthotopic Tx of a genetically engineered pig liver could theoretically provide successful bridging. Immediate availability, perfect metabolic condition, adequate size-match and hepatocyte mass, and freedom from potentially pathogenic microorganisms could be assured. The advantages and disadvantages of bridging by pig liver Tx compared with other approaches are discussed. The selection of patients for an initial clinical trial of pig liver Tx would be similar to that of various prior trials in patients experiencing rapid and severe deterioration in liver function. The ability to give truly informed consent for a pig bridging procedure at the time of listing for liver Tx renders the patient with acute-on-chronic liver failure or primary allograft failure is a preferable candidate for this procedure than a patient who is admitted urgently with acute (fulminant) liver failure in whom consent may not be possible. Although several barriers to successful pig organ xenoTx remain, for example, coagulation dysfunction between pig and primate, if these can be resolved by further genetic engineering of the organ-source pigs, a pig liver may prove life saving to patients dying rapidly of liver failure.

Renal failure in patients with cirrhosis

Renal failure in cirrhosis poses unique diagnostic and therapeutic challenges. Laboratory values and predictive equations grossly overestimate renal function in patients with cirrhosis. Development of renal failure connotes a worse prognosis; mortality is especially high with hepatorenal syndrome. Classification of the causes of renal failure in patients with cirrhosis is provided with more extensive discussion of selected causes. Finally, a suggested diagnostic approach to renal failure in cirrhosis is given.

Acute kidney injury in cirrhosis

Acute renal failure (ARF), recently renamed acute kidney injury (AKI), is a relatively frequent problem, occurring in approximately 20% of hospitalized patients with cirrhosis. Although serum creatinine may underestimate the degree of renal dysfunction in cirrhosis, measures to diagnose and treat AKI should be made in patients in whom serum creatinine rises abruptly by 0.3 mg/dL or more (>/=26.4 micromol/L) or increases by 150% or more (1.5-fold) from baseline. The most common causes of ARF (the term is used interchangeably with AKI) in cirrhosis are prerenal azotemia (volume-responsive prerenal AKI), acute tubular necrosis, and hepatorenal syndrome (HRS), a functional type of prerenal AKI exclusive of cirrhosis that does not respond to volume repletion. Because of the progressive vasodilatory state of cirrhosis that leads to relative hypovolemia and decreased renal blood flow, patients with decompensated cirrhosis are very susceptible to developing AKI with events associated with a decrease in effective arterial blood volume. HRS can occur spontaneously but is more frequently precipitated by events that worsen vasodilatation, such as spontaneous bacterial peritonitis.

CONCLUSION

Specific therapies of AKI depend on the most likely cause and mechanism. Vasoconstrictors are useful bridging therapies in HRS. Ultimately, liver transplantation is indicated in otherwise reasonable candidates in whom AKI does not resolve with specific therapy.