An Integrated Review of the Hepatorenal Syndrome

Physiological network approach to prognosis in cirrhosis: A shifting paradigm

Decompensated liver disease is complicated by multi-organ failure and poor prognosis. The prognosis of patients with liver failure often dictates clinical management. Current prognostic models have focused on biomarkers considered as individual isolated units. Network physiology assesses the interactions among multiple physiological systems in health and disease irrespective of anatomical connectivity and defines the influence or dependence of one organ system on another. Indeed, recent applications of network mapping methods to patient data have shown improved prediction of response to therapy or prognosis in cirrhosis. Initially, different physical markers have been used to assess physiological coupling in cirrhosis including heart rate variability, heart rate turbulence, and skin temperature variability measures. Further, the parenclitic network analysis was recently applied showing that organ systems connectivity is impaired in patients with decompensated cirrhosis and can predict mortality in cirrhosis independent of current prognostic models while also providing valuable insights into the associated pathological pathways. Moreover, network mapping also predicts response to intravenous albumin in patients hospitalized with decompensated cirrhosis. Thus, this review highlights the importance of evaluating decompensated cirrhosis through the network physiologic prism. It emphasizes the limitations of current prognostic models and the values of network physiologic techniques in cirrhosis.

Pharmacology of Tyrosine Kinase Inhibitors: Implications for Patients with Kidney Diseases

Tyrosine kinase inhibitors (TKI) have introduced a significant advancement in cancer management. These compounds are administered orally, and their absorption holds a pivotal role in determining their variable efficacy. They exhibit extensive distribution within the body, binding strongly to both plasma and tissue proteins. Often reliant on efflux and influx transporters, TKI undergo primary metabolism by intestinal and hepatic cytochrome P450 enzymes, with nonkidney clearance being predominant. Owing to their limited therapeutic window, many TKI display considerable intraindividual and interindividual variability. This review offers a comprehensive analysis of the clinical pharmacokinetics of TKI, detailing their interactions with drug transporters and metabolic enzymes, while discussing potential clinical implications. The prevalence of kidney conditions, such as AKI and CKD, among patients with cancer is explored in their effect on TKI pharmacokinetics. Finally, the potential nephrotoxicity associated with TKI is also examined.

Safety of Nonselective Beta-Blockers in Decompensated Liver Cirrhosis and Their Role in Inducing Hepatorenal Syndrome

Background Nonselective beta-blockers (NSBBs) have been used in the management of portal hypertension and the prevention of initial and recurrent variceal bleeding in patients with liver cirrhosis. However, there is controversy regarding the use of NSBBs in patients with decompensated cirrhosis (DC) due to concerns over potential adverse effects, such as worsening of hepatic function and risk of hepatorenal syndrome (HRS). HRS is a serious complication of DC characterized by acute kidney injury (AKI) and progressive renal failure, and its development can lead to significant morbidity and mortality in this setting. Therefore, using NSBBs in patients with DC remains an area of ongoing research and debate. Our study aims to investigate the potential effect of NSBBs on HRS development. Methodology A retrospective chart review of 404 patients with cirrhosis was performed across all Northwell Health institutions between January 01, 2019, and December 31, 2020. An analysis was done on 516 patient encounters. Inclusion criteria included patients with an established International Classification of Diseases 10th Revision code of cirrhosis and AKI. After adjusting for clinical predictors, the Student's t-test or Mann-Whitney U-test was used to compare variables between the two outcome groups (HRS vs. no HRS) for the continuous variables. Pearson's chi-square test or Fisher's exact test was used for the categorical variables to test if an association existed between the use of NSBBs at home and HRS. A two-sided p-value <0.05 was considered statistically significant. SAS 9.4 (SAS Institute Inc., Cary, NC, USA) was used for statistical analysis. Results The primary outcome was the development of HRS during the hospital stay. With a total of 109 visits with HRS, we had 21 (23.60%) reported HRS in the 89 visits where NSBBs were used at home before the hospitalization, while 88 (20.61%) HRS were observed in the 427 visits with no NSBB use at home. The use of NSBBs at home was not significantly associated with the development of HRS (odds ratio = 1.1, 95% confidence interval = 0.6-1.9, p = 0.7321). We also found that higher serum albumin on admission is associated with lower odds of HRS. In contrast, increased serum creatinine, bilirubin, presence of ascites, and use of pressors were associated with a higher risk of HRS. Conclusions Our study highlights the relevant safety of NSBB use in end-stage liver disease. Their use did not appear to increase the risk of developing HRS during hospitalization with DC. Further randomized controlled trials are warranted to shed more light on the efficacy, dose tolerance limits, and safety of NSBBs in decompensated end-stage liver disease.

Vasopressin in Sepsis and Other Shock States: State of the Art

This review of the use of vasopressin aims to be comprehensive and highly practical, based on the available scientific evidence and our extensive clinical experience with the drug. It summarizes controversies about vasopressin use in septic shock and other vasodilatory states. Vasopressin is a natural hormone with powerful vasoconstrictive effects and is responsible for the regulation of plasma osmolality by maintaining fluid homeostasis. Septic shock is defined by the need for vasopressors to correct hypotension and lactic acidosis secondary to infection, with a high mortality rate. The Surviving Sepsis Campaign guidelines recommend vasopressin as a second-line vasopressor, added to norepinephrine. However, these guidelines do not address specific debates surrounding the use of vasopressin in real-world clinical practice.

A Comprehensive Systematic Review of the Latest Management Strategies for Hepatorenal Syndrome: A Complicated Syndrome to Tackle

Hepatorenal syndrome (HRS), defined by the extreme manifestation of renal impairment in patients with cirrhosis, is characterized by reduced renal blood flow and glomerular filtration rate. It is diagnosed with reduced kidney function confirming the absence of intrinsic kidney disease, such as hematuria or proteinuria. HRS is potentially reversible with liver transplantation or vasoconstrictor drugs. The condition carries a poor prognosis with high mortality rates, particularly in patients with advanced cirrhosis. The latest management for HRS involves a combination of pharmacological and non-pharmacological interventions, aiming to improve renal function and reduce the risk of mortality. Pharmacological treatments include vasoconstrictors, such as terlipressin and midodrine, and albumin infusion, which have been shown to improve renal function and reduce mortality in HRS patients. Non-pharmacological interventions, including invasive procedures such as transjugular intrahepatic portosystemic shunt (TIPS), plasma exchange, liver transplantation, and renal replacement therapy, may also be considered. Though TIPS has been shown to be effective in improving renal function in HRS patients, liver transplantation remains at the top of the consideration for the treatment of end-stage liver disease and HRS. Recent studies have placed importance on early recognition and prompt intervention in HRS patients, as delaying treatment can result in poorer outcomes. Although there are numerous reviews that summarize various aspects of HRS, the recent advancements in the management and pathophysiology of HRS are still insufficient. Therefore, in this review, we summarized a brief pathophysiology and highlighted recent advancements in the management of HRS with a quick review of the latest articles.

Long-term renal outcomes comparison between patients with chronic kidney disease and hepatorenal syndrome after living donor liver transplantation

Background and aims

Hepatorenal syndrome (HRS) is a disastrous renal complication of advanced liver disease with a poor prognosis. Restoring normal liver function through liver transplantation (LT) is a standardized treatment with favorable short-term survival. However, the long-term renal outcomes in patients with HRS receiving living donor LT (LDLT) are controversial. This study aimed to investigate the prognostic impact of LDLT in patients with HRS.

Methods

We reviewed adult patients who underwent LDLT between July 2008 and September 2017. Recipients were classified into 1) HRS type 1 (HRS1, N = 11), 2) HRS type 2 (HRS2, N = 19), 3) non-HRS recipients with pre-existing chronic kidney disease (CKD, N = 43), and 4) matched normal renal function (N = 67).

Results

Postoperative complications and 30-day surgical mortality were comparable among the HRS1, HRS2, CKD, and normal renal function groups. The 5-year survival rate was &gt;90% and estimated glomerular filtration rate (eGFR) transiently improved and peaked at 4 weeks post-transplantation in patients with HRS. However, renal function deteriorated and resulted in CKD stage ≥ III in 72.7% of HRS1 and 78.9% of HRS2 patients (eGFR &lt;60 ml/min/1.73 m2). The incidence of developing CKD and end-stage renal disease (ESRD) was similar between the HRS1, HRS2, and CKD groups, but significantly higher than that in the normal renal function group (both P &lt; 0.001). In multivariate logistic regression, pre-LDLT eGFR &lt;46.4 ml/min/1.73 m2 predicted the development of post-LDLT CKD stage ≥ III in patients with HRS (AUC = 0.807, 95% CI = 0.617–0.997, P = 0.011).

Conclusions

LDLT provides a significant survival benefit for patients with HRS. However, the risk of CKD stage ≥ III and ESRD among patients with HRS was similar to that in pre-transplant CKD recipients. An early preventative renal-sparing strategy in patients with HRS is recommended.

Development and Validation of a Machine Learning Predictive Model for Cardiac Surgery-Associated Acute Kidney Injury

OBJECTIVE

We aimed to develop and validate a predictive machine learning (ML) model for cardiac surgery associated with acute kidney injury (CSA-AKI) based on a multicenter randomized control trial (RCT) and a Medical Information Mart for Intensive Care-IV (MIMIC-IV) dataset.

METHODS

This was a subanalysis from a completed RCT approved by the Ethics Committee of Fuwai Hospital in Beijing, China (NCT03782350). Data from Fuwai Hospital were randomly assigned, with 80% for the training dataset and 20% for the testing dataset. The data from three other centers were used for the external validation dataset. Furthermore, the MIMIC-IV dataset was also utilized to validate the performance of the predictive model. The area under the receiver operating characteristic curve (ROC-AUC), the precision-recall curve (PR-AUC), and the calibration brier score were applied to evaluate the performance of the traditional logistic regression (LR) and eleven ML algorithms. Additionally, the Shapley Additive Explanations (SHAP) interpreter was used to explain the potential risk factors for CSA-AKI.

RESULT

A total of 6495 eligible patients undergoing cardiopulmonary bypass (CPB) were eventually included in this study, 2416 of whom were from Fuwai Hospital (Beijing), for model development, 562 from three other cardiac centers in China, and 3517 from the MIMICIV dataset, were used, respectively, for external validation. The CatBoostClassifier algorithms outperformed other models, with excellent discrimination and calibration performance for the development, as well as the MIMIC-IV, datasets. In addition, the CatBoostClassifier achieved ROC-AUCs of 0.85, 0.67, and 0.77 and brier scores of 0.14, 0.19, and 0.16 in the testing, external, and MIMIC-IV datasets, respectively. Moreover, the utmost important risk factor, the N-terminal brain sodium peptide (NT-proBNP), was confirmed by the LASSO method in the feature section process. Notably, the SHAP explainer identified that the preoperative blood urea nitrogen level, prothrombin time, serum creatinine level, total bilirubin level, and age were positively correlated with CSA-AKI; preoperative platelets level, systolic and diastolic blood pressure, albumin level, and body weight were negatively associated with CSA-AKI.

CONCLUSIONS

The CatBoostClassifier algorithms outperformed other ML models in the discrimination and calibration of CSA-AKI prediction cardiac surgery with CPB, based on a multicenter RCT and MIMIC-IV dataset. Moreover, the preoperative NT-proBNP level was confirmed to be strongly related to CSA-AKI.

Current Medical Treatment for Alcohol-Associated Liver Disease

Alcohol-associated liver disease is one of the main causes of chronic liver disease. It comprises a clinical-histologic spectrum of presentations, from steatosis, steatohepatitis, to different degrees of fibrosis, including cirrhosis and severe necroinflammatory disease, called alcohol-associated hepatitis. In this focused update, we aim to present specific therapeutic interventions and strategies for the management of alcohol-associated liver disease. Current evidence for management in all spectra of manifestations is derived from general chronic liver disease recommendations, but with a higher emphasis on abstinence and nutritional support. Abstinence should comprise the treatment of alcohol use disorder as well as withdrawal syndrome. Nutritional assessment should also consider the presence of sarcopenia and its clinical manifestation, frailty. The degree of compensation of the disease should be evaluated, and complications, actively sought. The most severe acute form of this disease is alcohol-associated hepatitis, which has high mortality and morbidity. Current treatment is based on corticosteroids that act by reducing immune activation and blocking cytotoxicity and inflammation pathways. Other aspects of treatment include preventing and treating hepatorenal syndrome as well as preventing infections although there is no clear evidence as to the benefit of probiotics and antibiotics in prophylaxis. Novel therapies for alcohol-associated hepatitis include metadoxine, interleukin-22 analogs, and interleukin-1-beta antagonists. Finally, granulocyte colony-stimulating factor, microbiota transplantation, and gut-liver axis modulation have shown promising results. We also discuss palliative care in advanced alcohol-associated liver disease.

Update on hepatorenal Syndrome: Definition, Pathogenesis, and management

Hepatorenal syndrome (HRS) is acute kidney injury (AKI) that occurs without evidence of structural abnormalities in the kidneys in patients with liver disease. It is thought to be due to splanchnic vasculature dilatation that is associated with intense increase of renal arteries' tone, leading to renal cortex ischemia and AKI. Nitric oxide, endotoxins, neurohormonal changes, bacterial infection, high serum bilirubin and bile acids are examples for factors contributing to HRS development. Nevertheless, other unknown factors may have role in HRS pathophysiology. Hence, further discussion and research are needed to clearly understand HRS. Plasma volume restoration and vasoconstrictors are the cornerstone of HRS treatment. Others such as octreotide, noradrenaline, infection control, systemic inflammatory response prevention, shunting, and renal replacement therapy are currently used to manage HRS. Liver or combined liver and kidney transplantation is currently the ultimate cure for HRS. This review was written to help in better understanding the pathogenesis, diagnosis, and treatment options for HRS.

Reversal of hepatorenal syndrome and kidney recovery: When renal has more to offer

Hepatorenal syndrome (HRS) is one of the most severe complications in advanced cirrhosis. Type-1 HRS is relatively uncommon, yet carries considerably higher mortality rate. Effective treatment for HRS, especially therapy towards survival benefits, is still limited. However, the role for dialysis in HRS has been questioned over the years. The initiation of dialysis remains controversial for those who aren't transplant candidates. Meanwhile, there's a growing attention towards the successful use of peritoneal dialysis (PD) in cirrhotic patients. Herein, we report a case of HRS-1 in a 76-year-old male patient with decompensated cirrhosis. Through a series of adjustments of hemodialysis regimens and pharmacological prescriptions, patient stabilized and the opportunity for transjugular intrahepatic portosystemic shunt (TIPS) insertion was gained. PD was initiated after TIPS placement. With a gradual decrease of dialysis dose, patient successfully weaned off PD and achieved both reversal of HRS and kidney recovery. Markedly improved nutritional status and quality of life were reported. The potential role of dialysis and TIPS in HRS may be worth revisiting. Further studies regarding the optimal timing of dialysis initiation, choices of dialysis modality, and efficacy of dialysis therapy in combination with TIPS in HRS patients are warranted.

Vasopressin and Its Analogues: From Natural Hormones to Multitasking Peptides

Human neurohormone vasopressin (AVP) is synthesized in overlapping regions in the hypothalamus. It is mainly known for its vasoconstricting abilities, and it is responsible for the regulation of plasma osmolality by maintaining fluid homeostasis. Over years, many attempts have been made to modify this hormone and find AVP analogues with different pharmacological profiles that could overcome its limitations. Non-peptide AVP analogues with low molecular weight presented good affinity to AVP receptors. Natural peptide counterparts, found in animals, are successfully applied as therapeutics; for instance, lypressin used in treatment of diabetes insipidus. Synthetic peptide analogues compensate for the shortcomings of AVP. Desmopressin is more resistant to proteolysis and presents mainly antidiuretic effects, while terlipressin is a long-acting AVP analogue and a drug recommended in the treatment of varicose bleeding in patients with liver cirrhosis. Recently published results on diverse applications of AVP analogues in medicinal practice, including potential lypressin, terlipressin and ornipressin in the treatment of SARS-CoV-2, are discussed.

Predictors of Development of Hepatorenal Syndrome in Hospitalized Cirrhotic Patients with Acute Kidney Injury

Hepatorenal syndrome (HRS) is a type of acute kidney injury (AKI), occurring in patients with decompensated liver cirrhosis and is associated with high mortality. We aim to describe the predictors associated with the development of HRS in cirrhotic patients with AKI. We retrospectively analyzed 529 cirrhotic patient encounters with AKI across all Northwell Health institutions between 1 January 2015 and 31 December 2018. We performed multivariate analyses to determine independent predictors of development of HRS. Alcoholic cirrhosis was the most common identified etiology of cirrhosis. The mean Model for End-Stage Liver Disease Scorewas18 (±7). Ascites was the most commonly identified clinical feature of portal hypertension. Infection was identified in 38.4% of patients with urinary tract infection/pyelonephritis being the most common. Spontaneous bacterial peritonitis occurred in 5.9% of patients. The most common cause of AKI was pre-renal. Hepatorenal syndrome was identified in 9.8% of patient encounters. Predictors of HRS were history of ascites, serum creatinine >2.5 mg/dL, albumin <3 g/dL, bilirubin >2 mg/dL and spontaneous bacterial peritonitis. We demonstrate strong predictors for the development of HRS which can aid clinicians to attain an early diagnosis of HRS, leading to prompt and targeted management and improving outcomes.

Liver kidney crosstalk: Hepatorenal syndrome

The dying liver causes the suffocation of the kidneys, which is a simplified way of describing the pathophysiology of hepatorenal syndrome (HRS). HRS is characterized by reversible functional renal impairment due to reduced blood supply and glomerular filtration rate, secondary to increased vasodilators. Over the years, HRS has gained much attention and focus among hepatologists and nephrologists. HRS is a diagnosis of exclusion, and in some cases, it carries a poor prognosis. Different classifications have emerged to better understand, diagnose, and promptly treat this condition. This targeted review aims to provide substantial insight into the epidemiology, pathophysiology, diagnosis, and management of HRS, shed light on the various milestones of this condition, and add to our current understanding.

End-stage liver disease: Management of hepatorenal syndrome

Hepatorenal syndrome (HRS) is a serious complication of cirrhosis with high morbidity and mortality rates. Recently, the definition of HRS type 1 has been updated and is now called HRS-AKI. This new definition reduces the risk of delaying HRS treatment and eliminates the need to establish a minimum creatinine cut-off for the diagnosis of HRS-AKI. From a pathophysiological point of view, newly identified mechanisms involved in the development of HRS are related to the inflammatory response, conditioning the development of extrahepatic organ dysfunction in patients with cirrhosis. One of the main challenges for the diagnosis of HRS is the validation of new biomarkers to obtain an early and differential diagnosis of kidney injury (eg HRS vs. ATN). Treatment of HRS is based on the use of vasoconstrictive agents in combination with albumin and terlipressin is the most widely used vasoconstrictor drug, with a high response rate. The effects of a continuous infusion of terlipressin at a dose of 2-12 mg/day was similar to bolus administration, but with lower rates of adverse events. Finally, MELD/MELD-Na which includes creatinine as one of its main determinants gives AKI-HRS patients priority on the waiting list (WL) for liver transplant (LT). However, the MELD and MELD-Na scores are reduced in responding patients, resulting a longer waiting time in these patients than in non-responders. Thus, the initial MELD/MELD-Na score (pre-treatment value) should be used to prioritize patients on the WL for LT in these cases.