Relevance of New Definitions to Incidence and Prognosis of Acute Kidney Injury in Hospitalized Patients with Cirrhosis: A Retrospective Population-Based Cohort Study

Acute kidney injury stage 1a increases mortality of patients with cirrhosis: a prospective multicenter cohort study

BACKGROUND AND AIMS

Acute kidney injury is a severe complication of cirrhosis. However, the impact of mild decreases in renal function is controversial. This study aims to evaluate the prognosis of the different stages of acute kidney injury in cirrhosis.

METHODS

This is a multicenter prospective cohort study of patients hospitalized for acute decompensation of cirrhosis, with serum creatinine values measured at least twice. Primary outcome was mortality (in-hospital, 30 days, 90 days and 12 months).

RESULTS

Nine hundred twenty-eight patients were included in the study. Acute kidney injury was diagnosed in 505 patients (stages 1a-21.6%, 1b-27.5%, 2-28.1%, 3-22.8%). Mortality rates of patients with acute kidney injury stage 1a were significantly higher than those of individuals without acute kidney injury (in-hospital-19.3% vs 4.7%; 30-day-21.8% vs 6.7%; 90-day-35.2% vs 17.5%; 12-month-54.1% vs 37.1%; p < 0.05 for all comparisons). Mortality rates were even higher for acute kidney injury stages 1b, 2 and 3. Survival analysis demonstrated that patients without acute kidney injury performed significantly better than those with any stage of acute kidney injury (p < 0.01). Acute kidney injury stages 1a, 1b, 2 and 3 were independently associated with survival in the multivariate analysis (p < 0.01).

CONCLUSIONS

Patients hospitalized for acute decompensation of cirrhosis who develop acute kidney injury have significantly higher mortality rates than those who do not develop this complication. This is true even for the mildest stages of acute kidney injury (stage 1a) and remains so at different time-points, supporting recommendations for earlier treatments.

A novel risk-predicted nomogram for acute kidney injury progression in decompensated cirrhosis: a double-center study in Vietnam

OBJECTIVES

Acute kidney injury (AKI) is commonly encountered in patients hospitalized for decompensated cirrhosis and is associated with prolonged hospital stays, increased treatment burden, and even mortality. The present study aimed to determine the prevalence of and develop a predictive nomogram for AKI in patients with decompensated cirrhosis.

METHODS

This cross-sectional, double-center study involved 544 patients hospitalized with decompensated cirrhosis. Acute kidney injury was diagnosed using American Gastroenterological Association's guidelines with one more criterion: an increase in serum creatinine ≥ 0.3 mg/dL within 48 h or an increase in serum creatinine ≥ 50% compared to baseline serum creatinine or when the urine output is reduced below 0.5 mL/kg/h for > 6 h. We used the Bayesian model averaging method find the optimal model for predicting AKI. A predictive nomogram was also developed to enable risk prediction.

RESULTS

The overall AKI prevalence was 26.7% (95% Confidence interval [CI] 25.7-27.7). The optimal model for predicting AKI included diuretic therapy (odds ratio [OR]: 5.55; 95%CI 3.31-9.33), infection (OR: 2.06; 95%CI 1.31-3.22), ascites (OR: 3.20; 95%CT: 1.67-6.13), Child-Pugh group C (OR: 2.91; 95%CI 1.84-4.62), serum potassium (OR per 1 mmol/L increase: 1.62; 95%CI 1.25-2.1) and serum chloride (OR per 1 mmol/L decrease: 1.03; 95%CI 1.01-1.06). The area under the receiver operating characteristic curve was 0.8, with a 95%CI ranging from 0.75 to 0.84.

CONCLUSIONS

Acute kidney injury was relatively common among patients hospitalized for decompensated cirrhosis. A novel nomogram-including diuretic therapy, infection, ascites, Child-Pugh group C, serum potassium and, serum chloride, was helpful for the selective screening of AKI in patients with decompensated cirrhosis.

Mortality of Acute Kidney Injury in Cirrhosis: A Systematic Review and Meta-Analysis of Over 5 Million Patients Across Different Clinical Settings

BACKGROUND

Acute kidney injury (AKI) represents a commonly seen condition in the natural course of cirrhosis associated with unfavourable outcomes.

AIMS

To evaluate and compare the pooled mortality rates of patients with cirrhosis, with versus without AKI, across different clinical settings and diagnostic criteria.

METHODS

A systematic search of several databases was performed up to Oct 2023. Meta-analysis was performed using a generalised linear mixed model with a random effects model for all calculations.

RESULTS

A total of 59 studies comparing patients with cirrhosis, with and without AKI, were included in the meta-analysis, encompassing 1,153,193 individuals with AKI and 4,630,814 without AKI. AKI development predisposed to significantly higher short (in-hospital and 30-days)-, intermediate (90-days)- and long (1-year)-term mortality rates in both inpatients and outpatients. Remarkably, patients with AKI admitted to intensive care unit (ICU) or diagnosed with acute-on-chronic liver failure (ACLF) experienced the higher short-term mortality rates, reaching 76% [95% confidence interval (CI): 73%-79%] and 54% (95%CI: 33%-73%), respectively. AKI staging correlated with mortality risk, with higher stages indicating higher mortality rates, while the timing of AKI development, whether community-acquired or hospital-acquired, plays a crucial role in patient prognosis, with distinct mortality patterns observed in each group. The selection of diagnostic criteria for AKI may also impact its association with the short-term mortality risk.

CONCLUSIONS

AKI substantially affects the prognosis of patients with cirrhosis, especially those in ICU and/or with ACLF. Prognosis is also greatly influenced by the AKI stage, timing of onset and diagnostic criteria.

Association of Hepatorenal Syndrome-Acute Kidney Injury with Mortality in Patients with Cirrhosis Requiring Renal Replacement Therapy: Results from the HRS-HARMONY Consortium

Background:

While AKI requiring renal replacement therapy (AKI-RRT) is associated with increased mortality in heterogeneous inpatient populations, the epidemiology of AKI-RRT in hospitalized patients with cirrhosis is not fully known. Herein, we evaluated the association of etiology of AKI with mortality in hospitalized patients with cirrhosis and AKI-RRT in a multicentric contemporary cohort.

Methods:

This is a multicenter retrospective cohort study using data from the HRS-HARMONY consortium, which included 11 U.S. hospital network systems. Consecutive adult patients admitted in 2019 with cirrhosis and AKI-RRT were included. The primary outcome was 90-day mortality, and the main independent variable was AKI etiology, classified as hepatorenal syndrome (HRS-AKI) vs. other (non-HRS-AKI). AKI etiology was determined by at least two independent adjudicators. We performed Fine and Gray sub-distribution hazard analyses adjusting for relevant clinical variables.

Results:

Of 2,063 hospitalized patients with cirrhosis and AKI, 374 (18.1%) had AKI-RRT. Among these, 65 (17.4%) had HRS-AKI and 309 (82.6%) non-HRS-AKI, which included ATN in most cases (62.6%). Continuous RRT (CRRT) was used as the initial modality in 264 (71%) of patients, while intermittent hemodialysis (IHD) was utilized in 108 (29%). The HRS-AKI (vs. non-HRS-AKI) group received more vasoconstrictors for HRS management (81.5% vs. 67.9%), while the non-HRS-AKI group received more mechanical ventilation (64.3% vs. 50.8%) and more CRRT (vs. IHD) as the initial RRT modality (73.9% vs. 56.9%). In the adjusted model, HRS-AKI (vs. non-HRS-AKI) was not independently associated with increased 90-day mortality (sHR=1.36, 95% CI: 0.95-1.94).

Conclusions:

In this multicenter contemporary cohort of hospitalized adult patients with cirrhosis and AKI-RRT, HRS-AKI was not independently associated with an increased risk of 90-day mortality when compared to other AKI etiologies. The etiology of AKI appears less relevant than previously considered when evaluating the prognosis of hospitalized adult patients with cirrhosis and AKI requiring RRT.

The use of urinary kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin for diagnosis of hepato-renal syndrome in advanced cirrhotic patients

BACKGROUND

Chronic liver disease is a common and important clinical problem.Hepatorenal syndrome (HRS) is a life threatening complication. Serum creatinine (Cr) remains the only conventional indicator of renal function. However, the interpretation of serum Cr level can be confounded by malnutrition and reduced muscle mass often observed in patients with severe liver disease. Here, we present a cross-sectional study to explore the sensitivity and specificity of other markers as urinary KIM-1 and NGAL for cases of HRS.

METHODS

Cross-sectional study was conducted on 88 patients who were admitted to Alexandria main university hospital. Enrolled patients were divided in two groups; group 1: patients with advanced liver cirrhosis (child B and C) who have normal kidney functions while group 2: patients who developed HRS. Stata© version 14.2 software package was used for analysis.

RESULTS

Group 1 included 18 males and 26 females compared to 25 males and 19 females in group 2 (p = 0.135). Only the urinary KIM-1 showed a statistically significant difference between both groups in the multivariate logistic regression analysis adjusted for gender, serum bilirubin, serum albumin, INR, serum K, AST and ALT levels.

CONCLUSION

In conclusion, our study aligns with prior research, as seen in the consistent findings regarding Urinary NGAL elevation in cirrhotic patients with AKI. Urinary KIM-1, independent of Urinary NGAL, may have a role in precisely distinguishing between advanced liver cirrhosis and HRS and merits further exploration.

Association between serum magnesium concentrations and the risk of developing acute kidney injury in patients with cirrhosis: a retrospective cohort study based on the MIMIC-IV database

BACKGROUND

In various disease contexts, magnesium abnormalities are associated with acute kidney injury (AKI) incidence. However, this association remains unclear and has not been systematically investigated in patients with cirrhosis. Hence, we aimed to elucidate the association between admission serum magnesium levels and AKI incidence in intensive care unit (ICU)-admitted cirrhotic patients.

METHODS

A retrospective cohort study was conducted using MIMIC-IV2.2 data, focusing on critically ill patients with cirrhosis. We employed univariable and multivariable logistic regression and restricted cubic spline analyses to robustly address our research objectives. To further substantiate the findings, subgroup and sensitivity analyses were also conducted.

RESULTS

Among the 3,228 enrolled ICU-admitted cirrhotic patients, 34.4% were female, and the overall AKI incidence was 68.6% (2,213/3,228). Multivariable logistic regression analysis revealed an independent relationship between elevated serum magnesium levels and increased AKI risk (OR = 1.55 [95% CI = 1.15-2.09], p = 0.004). Compared with individuals with serum magnesium levels < 1.6 mg/dL, individuals with serum magnesium levels in Q2 (1.6-2.6 mg/dL) and Q3 (≥2.6 mg/dL) had adjusted ORs for AKI of 1.89 (95% CI = 1.34-2.65, p < 0.001) and 2.19 (95% CI = 1.27-3.75, p = 0.005), respectively. The restricted cubic spline analysis revealed that AKI risk increased linearly with increasing serum magnesium levels. Subgroup analysis revealed that the association between serum magnesium levels and AKI incidence was remarkably stable in subgroup analysis (all Pinteraction >0.05).

CONCLUSIONS

High serum magnesium concentrations were significantly associated with an increased AKI risk in ICU-admitted patients with cirrhosis. Further randomized trials are needed to confirm this association.

Study of prevalence, risk factors for acute kidney injury, and mortality in liver cirrhosis patients

INTRODUCTION

Acute kidney injury (AKI) occurs frequently in patients with end-stage liver disease and cirrhosis and is associated with increased short-term mortality. This study aims to study the prevalence and risk factors associated with AKI development and mortality in cirrhosis of liver patients.

METHODOLOGY

In the current prospective study, hospitalized patients with liver cirrhosis from October 2021 to March 2023 were recruited. Demographic, clinical, and laboratory data were collected, which included, the etiology of cirrhosis, comorbidities, severity of liver disease, and relevant biochemical parameters. The patient was followed up for 90 days to record the clinical outcome. The statistical software SPSS was utilized to conduct the analysis.

RESULTS

Of 364 liver cirrhosis patients, 25.2% (n, 92) had AKI and belonged to an average age of 51.54 ± 11.82 years. The majority of individuals in the study were males (90.4%), and alcohol (63.4%) was the most common etiology of liver cirrhosis. The present study showed that higher level of direct bilirubin (p = 0.011) and MELD score (p = 0.0001) were identified as significant risk factors for AKI development in patients with liver cirrhosis. Regarding mortality, the significant risk factors were the presence of AKI (p = 0.045) and MELD score (p = 0.025). Among AKI patients, 90-day mortality rates were higher in patients with acute tubular necrosis (p value = 0.010) and stage 3 AKI (p value = 0.001).

CONCLUSION

AKI is common in cirrhosis of liver patients. Elevated levels of direct bilirubin and MELD score emerged as significant factors associated with AKI development. Furthermore, AKI and MELD scores were identified as independent risk factors for mortality at both 30 and 90 days. Survival rates were influenced by both the type and stage of AKI; AKI stage 3 and ATN patients had significantly higher mortality rate. Early AKI detection and management are crucial for reducing mortality risk in liver cirrhosis patients.

Renal Complications in Portal Hypertension

Acute kidney injury (AKI) is a common complication among patients with decompensated cirrhosis and its development is associated with worse prognosis in terms of survival. Patients with decompensated cirrhosis may develop a unique type of AKI, known as hepatorenal syndrome (HRS-AKI), characterized by marked impairment of kidney function due to haemodynamic changes that occur in late stages of liver cirrhosis. Besides, patients with cirrhosis also may develop chronic alterations of kidney function (chronic kidney disease, CKD), the incidence of which is increasing markedly and may be associated with clinical complications. The aim of this review is to provide the reader with an update of the most relevant aspects of alterations of kidney function in patients with cirrhossi that may be useful for theri clinical practice.

Acute kidney injury in patients with cirrhosis: Acute Disease Quality Initiative (ADQI) and International Club of Ascites (ICA) joint multidisciplinary consensus meeting

Patients with cirrhosis are prone to developing acute kidney injury (AKI), a complication associated with a markedly increased in-hospital morbidity and mortality, along with a risk of progression to chronic kidney disease. Whereas patients with cirrhosis are at increased risk of developing any phenotype of AKI, hepatorenal syndrome (HRS), a specific form of AKI (HRS-AKI) in patients with advanced cirrhosis and ascites, carries an especially high mortality risk. Early recognition of HRS-AKI is crucial since administration of splanchnic vasoconstrictors may reverse the AKI and serve as a bridge to liver transplantation, the only curative option. In 2023, a joint meeting of the International Club of Ascites (ICA) and the Acute Disease Quality Initiative (ADQI) was convened to develop new diagnostic criteria for HRS-AKI, to provide graded recommendations for the work-up, management and post-discharge follow-up of patients with cirrhosis and AKI, and to highlight priorities for further research.

Incidence and risk factors of acute kidney injury in cirrhosis: a systematic review and meta-analysis of 5,202,232 outpatients, inpatients, and ICU-admitted patients

INTRODUCTION

Acute kidney injury (AKI) is a commonly seen condition in the natural course of cirrhosis. The aim of this study was to evaluate the pooled incidence and risk factors of AKI in different clinical stages and situations in patients with cirrhosis.

METHODS

Search was conducted on 13 December 2023 across MEDLINE (PubMed), Embase, and Cochrane databases. Meta-analysis was performed using a generalized linear mixed model.

RESULTS

In total, 73 studies with 5,202,232 patients were finally enrolled in the meta-analysis. AKI commonly occurs among hospitalized cirrhotics experiencing any decompensation event (29%) as well as among stable outpatients (28%) throughout a 1-year follow-up period. On admission, patients with infection or sepsis/septic shock had the highest AKI rate (47%), followed by those with hepatic encephalopathy (41%). Furthermore, the severity of liver disease proved to be a substantial driver for AKI development, while patients at intensive care unit had the greatest AKI incidence (61%).

CONCLUSIONS

Both hospitalized patients and stable outpatients with cirrhosis exhibited an elevated susceptibility to AKI. Patients at intensive care unit and those with severe liver disease, infection, sepsis/septic shock, hepatic encephalopathy, or acute on chronic liver failure upon admission are at higher risk for AKI.

TRIAL REGISTRATION

PROSPERO, registered 09/12/23, CRD42023487736.

Acute Kidney Injury in Chronic Liver Disease in Northwest India: Still a Battle to Conquer

Background

Patients with cirrhosis are susceptible to development of acute kidney injury (AKI), which leads to poor outcome. We conducted a study to evaluate the spectrum of AKI in patients with cirrhosis.

Materials and Methods

This study was conducted in consecutive cirrhotic patients with AKI admitted in a tertiary care center of India from April 2020 to December 2022. Details including history, examination findings, and results of laboratory investigations were recorded.

Results

A total of 243 patients were enrolled in this study. The majority (91.3%) of the patients were males. The most common etiology of cirrhosis was alcohol in 58.4% (n = 142) followed by hepatitis B in 10.3% (n = 25) of patients. Pre-renal form of AKI was present in 54.4% (n = 132) of patients and hepatorenal syndrome (HRS) in 21.8% (n = 53) of patients. IgA nephropathy was the commonest (n = 6) glomerular pathology in nonresponders with intrinsic renal disease. Majority of the patients belonged to stage II (46.9%) and stage I AKI (37%), while only 16.1% had stage III AKI. Various stages of AKI showed a significant correlation (P < 0.05) with Child-Turcotte-Pugh (CTP) score and Model for End-stage Liver Disease (MELD)-Na score. The overall in-hospital mortality rate was found to be 18.5% (n = 45).

Conclusion

Renal dysfunction is a frequent complication among cirrhotic patients. Pre-renal factors were the most common cause of AKI in cirrhotics. Stages of AKI showed significant correlation with liver prognostic scores. Renal biopsy should be considered in patients not responding to treatment, to guide further management.

Seeing and Sensing the Hepatorenal Syndrome (HRS): The Growing Role of Ultrasound-Based Techniques as Non-Invasive Tools for the Diagnosis of HRS

More than half of patients hospitalized with liver cirrhosis are dealing with an episode of acute kidney injury; the most severe pattern is hepatorenal syndrome due to its negative prognosis. The main physiopathology mechanisms involve renal vasoconstriction and systemic inflammation. During the last decade, the definition of hepatorenal syndrome changed, but the validated criteria of diagnosis are still based on the serum creatinine level, which is a biomarker with multiple limitations. This is the reason why novel serum and urinary biomarkers have been intensively studied in recent years. Meanwhile, the imaging studies that use shear wave elastography are using renal stiffness as a surrogate for an early diagnosis. In this article, we focus on the physiopathology definition and highlight the novel tools used in the diagnosis of hepatorenal syndrome.

Predictors of Acute Kidney Injury in Patients Hospitalized With Liver Cirrhosis: A Systematic Review and Meta-Analysis

Acute kidney injury (AKI) frequently occurs in hospitalized individuals with liver cirrhosis and represents a significant risk factor for early in-hospital mortality, holding crucial clinical and prognostic importance. The objective of this meta-analysis was to assess the risk factors associated with AKI in hospitalized individuals with cirrhosis. This systematic review and meta-analysis was conducted in concordance with guidelines provided by the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement. Two independent researchers systematically searched major databases, including MEDLINE/PubMed, Web of Science, and EMBASE, from January 2015 until December 2023. A total of 14 studies were included in this meta-analysis, of which six were prospective, and the remaining were retrospective. Of the 9,659 cirrhosis patients in the 14 included studies, 3,968 had developed AKI with a pooled incidence of 41% (95% confidence interval = 34-47%). Our findings showed that a high Model for End-Stage Liver Disease (MELD) score, infection, high Child-Pugh-Turcotte stage score, high serum creatinine, high serum bilirubin, and low serum albumin were significantly associated with high incidence of AKI in liver cirrhosis patients. The results emphasize the importance of vigilant monitoring in cirrhosis patients to detect any indications of AKI, followed by meticulous and attentive management.

Essentials of Liver Transplantation in the Setting of Acute Kidney Injury and Chronic Kidney Disease

Kidney dysfunction is common among liver transplant candidates with decompensated cirrhosis and has a major impact on pre- and post-liver transplant survival. Updated definitions of acute kidney injury and criteria for the diagnosis of hepatorenal syndrome allow for early recognition and intervention, including early initiation of vasoconstrictor therapy for hepatorenal syndrome. The rise of the metabolic syndrome and nonalcoholic fatty liver disease as a cause of cirrhosis has coincided with an increase in intrinsic chronic kidney disease recognized in transplant candidates and recipients. Ultimately, the ability to accurately assess kidney function and associated risk is essential to decision-making in the context of transplantation, including selection of candidates for simultaneous liver and kidney transplantation.

Acute kidney injury in patients with acute-on-chronic liver failure: clinical significance and management

Acute-on-chronic-liver failure (ACLF) refers to a phenomenon in which patients with chronic liver disease develop multiple organ failure due to acute exacerbation of underlying liver disease. More than 10 definitions of ACLF are extant around the world, and there is lack of consensus on whether extrahepatic organ failure is a main component or a consequence of ACLF. Asian and European consortiums have their own definitions of ACLF. The Asian Pacific Association for the Study of the Liver ACLF Research Consortium does not consider kidney failure as a diagnostic criterion for ACLF. Meanwhile, the European Association for the Study of the Liver Chronic Liver Failure and the North American Consortium for the Study of End-stage Liver Disease do consider kidney failure as an important factor in diagnosing and assessing the severity of ACLF. When kidney failure occurs in ACLF patients, treatment varies depending on the presence and stage of acute kidney injury (AKI). In general, the diagnosis of AKI in cirrhotic patients is based on the International Club of Ascites criteria: an increase of 0.3 mg/dL or more within 48 hours or a serum creatinine increase of 50% or more within one week. This study underscores the importance of kidney failure or AKI in patients with ACLF by reviewing its pathophysiology, prevention methods, and treatment approaches.

Novel biomarkers of acute kidney injury in chronic liver disease: Where do we stand after a decade of research?

Acute kidney injury (AKI) is a frequently encountered complication in decompensated chronic liver disease (CLD) with an estimated prevalence of 20%-50% among hospitalized patients. AKI often heralds the onset of a downhill course in the natural history of CLD. Serum creatinine has several limitations as a stand-alone marker of AKI in patients with decompensated CLD. The concept of hepatorenal syndrome, the prototype of AKI in decompensated CLD, has evolved tremendously over recent years. There is emerging evidence of an additional "structural" component in the pathophysiology of hepatorenal syndrome-AKI, which was previously identified as a purely "functional" form of renal impairment. Lacunae in the existent biochemical arsenal for diagnosis and prognosis of AKI have fueled enthusiastic research in the field of novel biomarkers of kidney injury in patients with cirrhosis. The advent of these biomarkers provides a crucial window of opportunity to improve the diagnosis and clinical outcomes of this vulnerable cohort of patients. This review summarizes the dynamic concept of renal dysfunction in CLD and the available literature on the role of novel biomarkers of AKI in assessing renal function, identifying AKI subtypes, and predicting prognosis. There is special emphasis on the renal tubular injury marker, neutrophil gelatinase-associated lipocalin, the most exhaustively studied biomarker of AKI in the CLD population.

Impact of acute kidney injury on the risk of mortality in patients with cirrhosis: a systematic review and meta-analysis

Objective

To compare the risk of mortality in patients with cirrhosis with and without the associated acute kidney injury (AKI).

Methods

We performed a systematic search in the PubMed, Embase, and Scopus databases for observational studies that were done on patients with cirrhosis. Eligible studies reported AKI in patients with cirrhosis and compared mortality among patients with and without AKI. We used a random-effects model, using STATA version 16.0, for deriving pooled effect sizes that were reported as odds ratio (OR) with 95% confidence intervals (CIs).

Results

Thirty-two studies were included. In patients with cirrhosis, AKI was significantly associated with higher in-hospital mortality (OR 5.92), and mortality at 30 days (OR 4.78), 90 days (OR 4.34), and at 1 year follow-up (OR 4.82) compared to patients without AKI.

Conclusions

AKI is associated with an increased risk of mortality in patients with cirrhosis. Careful monitoring to identify the development of AKI and early prompt management is necessary.

Toll-like receptor 4 signaling pathway mediates both liver and kidney injuries in mice with hepatorenal syndrome

Hepatorenal syndrome (HRS) is a complication of cirrhosis with high morbidity and mortality. Nevertheless, the underlying mechanism involving how kidney injury aggravates the progression of cirrhosis remains unclear. This study aims to explore the role of the Toll-like receptor 4 (TLR4) signaling pathway in mediating liver and kidney injuries in HRS mice induced by unilateral ureteral obstruction (UUO) and/or bile duct ligation (BDL). Two weeks after UUO, there were no obvious pathological changes in mouse liver and the unligated side of kidney. Nevertheless, impaired liver and kidney functions, inflammatory response, and fibrosis were examined in mice after 2 wk of BDL. Compared with those of other groups, mice in the BDL + UUO group presented severer liver and kidney injuries, higher levels of inflammatory factors, and faster deposition of collagens, suggesting that kidney injuries accelerated the aggravation of HRS. Correlation analysis identified a positive correlation between expression levels of inflammatory factors and fibrotic levels. Meanwhile, TLR4 and its ligand MyD88 were upregulated during the process of liver and kidney injuries in HRS mice. Further animal experiments in transgenic TLR4^-/- mice or in those treated with TAK242, a small molecule inhibitor of TLR4, showed that blocking the TLR4 signaling pathway significantly improved survival quality and survival rate in HRS mice by alleviating liver fibrosis and kidney injury. It is concluded that kidney dysfunction plays an important role in the aggravation of cirrhosis, which may be attributed to the TLR4 signaling pathway. Targeting TLR4 could be a promising therapeutic strategy for protecting both liver and kidneys in patients with HRS.NEW & NOTEWORTHY Our study established BDL, UUO, and BDL + UUO models, providing a novel idea for analyzing liver and kidney diseases. It is highlighted that the kidney injury accelerated the aggravation of HRS via inflammatory response, which could be protected by inhibiting the TLR4 signaling pathway. We believed that targeting TLR4 was a promising therapeutic strategy for protecting both liver and kidney functions in patients with HRS.

Mastering Core Recommendations during HEPAtology ROUNDS in Patients with Advanced Chronic Liver Disease

Efficient and thorough care of hospitalized patients with advanced chronic liver disease is of utter importance to improve outcomes and optimize quality of life. This requires understanding current evidence and best practices. To facilitate focus on up-to-date knowledge and a practical approach, we have created the HEPA-ROUNDS mnemonic while outlining a practical review of the literature with critical appraisal for the busy clinician. The HEPA-ROUNDS mnemonic provides a structured approach that incorporates critical concepts in terms of prevention, management, and prognostication of the most common complications frequently encountered in patients with advanced chronic liver disease. In addition, implementing the HEPA-ROUNDS mnemonic can facilitate education for trainees and staff caring for patients with advanced chronic liver disease.

Patterns of kidney dysfunction in acute-on-chronic liver failure: Relationship with kidney and patients' outcome

Impairment of kidney function is common in acute-on-chronic liver failure (ACLF). Patterns of kidney dysfunction and their impact on kidney and patient outcomes are ill-defined. Aims of the current study were to investigate patterns of kidney dysfunction and their impact on kidney and patient outcomes in patients with acute decompensation (AD) of cirrhosis, with or without ACLF. This prospective study includes 639 admissions for AD (232 with ACLF; 407 without) in 518 patients. Data were collected at admission and during hospitalization, and patients were followed up for 3 months. Urine samples were analyzed for kidney biomarkers. Most patients with ACLF (92%) had associated acute kidney injury (AKI), in most cases without previous chronic kidney disease (CKD), whereas some had AKI-on-CKD (70% and 22%, respectively). Prevalence of AKI in patients without ACLF was 35% (p < 0.001 vs. ACLF). Frequency of CKD alone was low and similar in both groups (4% and 3%, respectively); only a few patients with ACLF (4%) had no kidney dysfunction. AKI in ACLF was associated with poor kidney and patient outcomes compared with no ACLF (AKI resolution: 54% vs. 89%; 3-month survival: 51% vs. 86%, respectively; p < 0.001 for both). Independent predictive factors of 3-month survival were Model for End-Stage Liver Disease-Sodium score, ACLF status, and urine neutrophil gelatinase-associated lipocalin (NGAL). AKI is almost universal in patients with ACLF, sometimes associated with CKD, whereas CKD alone is uncommon. Prognosis of AKI depends on ACLF status. AKI without ACLF has good prognosis. Best predictors of 3-month survival are MELD-Na, ACLF status, and urine NGAL.

Frailty as Tested by the Clinical Frailty Scale Is a Risk Factor for Hepatorenal Syndrome in Patients With Liver Cirrhosis

INTRODUCTION

Frailty is common in patients with cirrhosis and increases the vulnerability to internal and external stressors. This study aimed to investigate the impact of frailty, as defined by the Clinical Frailty Scale (CFS), on the risk of acute kidney injury (AKI) and hepatorenal syndrome (HRS-AKI) in hospitalized patients with liver cirrhosis.

METHODS

We analyzed data of 201 nonelectively hospitalized patients with cirrhosis and without higher-grade chronic kidney disease. Patient characteristics were captured within the first 24 hours of hospital admission, and frailty was assessed using the CFS. Patients were followed for the development of AKI and/or HRS-AKI during the hospital stay.

RESULTS

In the total cohort, median CFS was 3 (interquartile range 3-4), and 34 (16.9%) patients were frail (CFS >4). During the hospital stay, 110 (54.7%) and 49 (24.3%) patients developed AKI or HRS-AKI, respectively. Patients with AKI or HRS-AKI had a significantly higher CFS than patients without kidney injury (P < 0.001 each). In multivariable analyses, a higher CFS was independently associated with the development of AKI (odds ratio [OR] 1.467, 95% confidence interval (CI) 1.065-2.021) in the total cohort and HRS-AKI (OR 1.809, 95% CI 1.263-2.591) in the subcohort of patients with a history of ascites. In addition, there was a strong association between frailty (OR 3.717, 95% CI 1.456-9.491) and HRS-AKI.

DISCUSSION

Frailty in patients with cirrhosis is associated with AKI and HRS-AKI. In this context, CFS appears to be a reliable tool to identify patients at high risk for developing AKI or HRS-AKI on hospital admission.

Duodenal Necrosis and Nonvariceal Digestive Bleeding After Terlipressin Administration for Treatment of Hepatorenal Syndrome: a Case Report of a Novel Side Effect of a Commonly Used Drug

BACKGROUND

Terlipressin is widely used for treatment of hepatorenal syndrome and variceal bleeding in cirrhotic patients. However, it may be associated with side effects, especially those related to vasoconstriction, such as myocardial infarction or intestinal ischemia. This is a case report of a cirrhotic patient with nonvariceal upper gastrointestinal bleeding after duodenal necrosis due to the use of terlipressin, a novel side effect not yet described in literature to the best of our knowledge.

CASE REPORT

A 51-year-old male patient, with alcoholic liver cirrhosis and hepatitis C virus infection, was admitted presenting oliguria associated with severe ascites and lower limb edema. His Model for End Stage Liver Disease-Sodium score was 19 and his serum creatine level was 2.12 mg/dL. Albumin infusion was performed for 48 hours, but his serum creatinine level reached 3.46 mg/dL. Terlipressin infusion was started in continuous infusion and serum creatinine levels progressively decreased. However, the patient presented hemorrhagic shock secondary to hematemesis after 7 days. Upper digestive endoscopy showed an extensive ulcerated lesion in the duodenal bulb, reaching 70% of its lumen, with hematic residues and necrotic foci. Terlipressin was suspended and proton pump inhibitors were started. Despite intensive care, the patient developed severe encephalopathy and reentrant seizures. He eventually died 10 days after the bleeding event.

CONCLUSIONS

We described a case of nonvariceal upper gastrointestinal bleeding secondary to duodenal necrosis, which was caused by visceral ischemia induced by terlipressin. Given its fatality potential, this novel side effect should be remembered when using this medication in cirrhotic patients.

Race Adjustment in eGFR Equations Does Not Improve Estimation of Acute Kidney Injury Events in Patients with Cirrhosis

BACKGROUND

Accuracy of glomerular filtration rate estimating (eGFR) equations has significant implications in cirrhosis, potentially guiding simultaneous liver kidney allocation and drug dosing. Most equations adjust for Black race, partially accounted for by reported differences in muscle mass by race. Patients with cirrhosis, however, are prone to sarcopenia which may mitigate such differences. We evaluated the association between baseline eGFR and incident acute kidney injury (AKI) in patients with cirrhosis with and without race adjustment.

METHODS

We conducted a retrospective national cohort study of veterans with cirrhosis. Baseline eGFR was calculated using multiple eGFR equations including Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), both with and without race adjustment. Poisson regression was used to investigate the association between baseline eGFR and incident AKI events per International Club of Ascites criteria.

RESULTS

We identified 72,267 patients with cirrhosis, who were 97.3% male, 57.8% white, and 19.7% Black. Over median follow-up 2.78 years (interquartile range 1.22-5.16), lower baseline eGFR by CKD-EPI was significantly associated with higher rates of AKI in adjusted models. For all equations this association was minimally impacted when race adjustment was removed. For example, removal of race adjustment from CKD-EPI resulted in a 0.1% increase in the association between lower eGFR and higher rate of AKI events per 15 mL/min/1.73 m² change (p < 0.001).

CONCLUSIONS

Race adjustment in eGFR equations did not enhance AKI risk estimation in patients with cirrhosis. Further study is warranted to assess the impacts of removing race from eGFR equations on clinical outcomes and policy.

Acute kidney injury in patients with cirrhosis: Prospective longitudinal study in 405 patients

BACKGROUND

Acute kidney injury (AKI) is common in patients with cirrhosis. In 2015, the International Club of Ascites (ICA) proposed new definitions of AKI in order to improve the prediction of outcomes. Our aim was to assess the prevalence and prognostic value of ICA 2015 - AKI criteria in hospitalised patients with cirrhosis.

METHODS

We prospectively collected data from 405 consecutive cirrhotic patients admitted to the hospital between November 2016 and November 2017. AKI was diagnosed at inclusion according to ICA 2015 criteria, and was assessed to predict 30-day and 90-day in-hospital mortality.

RESULTS

AKI was diagnosed in 78 (19.3%) patients. AKI was independently associated with 90-day death (HR 7.61; 95% CI 4.75-12.19; p < 0.001). In hospital, 30-day and 90-day survival was lower in the group of patients with AKI compared to the group with no AKI (72% vs. 98%, p < 0.001; 64% vs. 96%, p < 0.001; and 49% vs. 81%, p < 0.001, respectively). Patients with stage 1a AKI had a lower 30-day and 90-day survival compared to the group of patients who did not develop AKI (71% vs. 96%, p < 0.001, and 71% vs. 91%, p < 0.01, respectively) and better survival than patients with more severe AKI (71% vs. 40%, p < 0.01).

CONCLUSIONS

AKI was independently associated with mortality in patients with cirrhosis, even at the very early 1a stage. Response to treatment improved survival, and was inversely proportional to the stage of AKI, which suggests that treatment should be started at the earliest stage of AKI.

Do old urinary biomarkers have a place in the new definition of hepatorenal syndrome in the Egyptian cirrhotic patients? A single-center experience

Background

Hepatorenal syndrome is still a diagnosis of exclusion despite new classification.

Aims

To validate the accuracy of urinary neutrophil gelatinase-associated lipocalin, interleukin-18, and kidney injury molecule-1 in the new diagnostic criteria of hepatorenal syndrome in Egyptian patients with hepatitis C virus-related liver cirrhosis using serum creatinine as a gold standard test for acute kidney injury.

Methods

One-hundred twenty cirrhotic patients with ascites were recruited and divided into two groups depending on the presence or absence of renal impairment, and 40 age- and sex-matched cirrhotic patients without ascites used as controls participated in the study. Urinary biomarkers were measured and compared with conventional biomarkers used to assess kidney function (serum creatinine, estimated glomerular filtration rate).

Results

The mean urinary neutrophil gelatinase-associated lipocalin, interleukin-18, and kidney injury molecule-1 were statistically significantly higher in patients with hepatorenal syndrome and were found to be helpful in the early detection with cutoff values of 125 ng/ml, 34.8 pg/ml, and 3.1 pg/ml, respectively.

Conclusions

Urinary neutrophil gelatinase-associated lipocalin, interleukin-18, and kidney injury molecule-1 levels are higher in patients with cirrhotic ascites complicated by HRS-AKI using the new definition of HRS, but IL-18 has lower sensitivity and specificity for the prediction of HRS-AKI as compared to NGAL and KIM-1.

Acute Kidney Injury in Patients with Liver Cirrhosis: Prevalence, Predictors, and In-Hospital Mortality at a District Hospital in Ghana

Background

Acute kidney injury (AKI) is one of the most severe complications of cirrhosis and portends an ominous prognosis with an estimated mortality of about 50% in a month and 65% within a year. Infection and hypovolemia have been found to be the main precipitating factors of AKI in liver cirrhosis. Early detection and treatment of AKI may improve outcomes. AKI in patients with liver cirrhosis in Ghana and their impact on inpatient mortality are largely unknown. This study was aimed at determining the prevalence, precipitating factors, predictors, and in-hospital mortality of AKI in patients with liver cirrhosis admitted to a district hospital in Ghana.

Methods

Consecutive hospitalized patients with liver cirrhosis from 1 January 2018 to 30 April 2020 were recruited. Patient's demographic data and clinical features were collected using a standardized questionnaire. Biochemical and haematological tests as well as abdominal ultrasound scans were done for all patients. All patients were then followed up until discharge or death.

Results

There were 117 (65.4%) males out of the 179 patients with a mean age of 49.94 and 45.84 years for those with and without AKI, respectively. The prevalence of AKI was 27.9% (50/179). Out of 50 participants with AKI, 64.0% (32/50) died, contributing 41.0% of all in-patient mortality amongst participants. There was a significant association between AKI and death (p ≤ 0.001). The major precipitating factors of AKI were infections (60.0%), hypovolemia (20.0%) due to gastrointestinal bleeding and gastroenteritis, and refractory ascites (16.0%). Alkaline phosphatase, INR, model for end-stage liver disease sodium, sodium, and blood urea nitrogen were independent predictors of AKI.

Conclusion

AKI was common among patients with liver cirrhosis with high in-patient mortality. Identification of these precipitants and independent predictors of AKI may lead to prompt and targeted treatment with reduction in patient mortality.

Recovery From Acute Kidney Injury Requiring Dialysis in Patients With Cirrhosis: A Population-Based Study

RATIONALE & OBJECTIVE

The decision to initiate kidney replacement therapy (KRT) for acute kidney injury (AKI) in cirrhosis remains controversial as it is unclear which patients will benefit. We sought to characterize factors associated with recovery from AKI requiring KRT in patients with cirrhosis to inform shared clinical decision-making.

STUDY DESIGN

Population-based retrospective cohort study.

SETTING & PARTICIPANTS

Adult patients from Ontario, Canada identified, using administrative data, to have cirrhosis at the time of admission to hospital with AKI (based on serum creatinine) requiring KRT (01/01/2009-12/31/2016) and followed until 12/31/2017.

EXPOSURES

Demographics and comorbidities prior to admission.

OUTCOMES

Kidney recovery defined as the absence of KRT for at least 30 days.

ANALYTICAL APPROACH

The cumulative incidences of kidney recovery, death, and liver transplantation were calculated at 1, 3, 6, and 12 months and independent predictors of kidney recovery were evaluated using Fine and Gray competing risk regression models that generated subdistribution hazards ratios (sHR).

RESULTS

Overall, 722 patients were included (median age 61 years [IQR 54-68]; MELD-Na 26 [IQR 22-34]; 66% male; 52% had viral hepatitis, 25% non-alcoholic fatty liver disease, 18% alcohol-associated liver disease). The cumulative incidences of kidney recovery at 1, 3, 6, and 12 months were 3%, 22%, 25%, and 26%, respectively. Higher MELD-Na score (sHR 0.72 per 5 units, 95%CI 0.65-0.80), acute-on-chronic liver failure (sHR 0.61, 95%CI 0.43-0.86), and sepsis (sHR 0.57, 95%CI 0.41-0.81) were associated with a lower hazard of kidney recovery while those on a liver transplant waitlist (sHR 3.10, 95% CI 1.96-4.88) and who were admitted to a teaching hospital (sHR 1.48, 95%CI 1.05-2.08) were more likely to experience kidney recovery.

LIMITATIONS

Observational design, AKI etiology not identified.

CONCLUSIONS

Kidney recovery from KRT occurred in only one-quarter of patients and was very unlikely after 3-months. These findings provide information regarding prognosis that may guide decisions regarding KRT initiation and continuation.

Post-Liver Transplant Acute Kidney Injury

Acute kidney injury (AKI) is a common condition following liver transplantation (LT). It negatively impacts patient outcomes by increasing the chances of developing chronic kidney disease and reducing graft and patient survival rates. Multiple definitions of AKI have been proposed and used throughout the years, with the International Club of Ascites definition being the most widely now used for patients with cirrhosis. Multiple factors are associated with the development of post-LT AKI and can be categorized into pre-LT comorbidities, donor and recipient characteristics, operative factors, and post-LT factors. Many of these factors can be optimized in an attempt to minimize the risk of AKI occurring and to improve renal function if AKI is already present. A special consideration during the post-LT phase is needed for immunosuppression as certain immunosuppressive medications can be nephrotoxic. The calcineurin inhibitor tacrolimus (TAC) is the mainstay of immunosuppression but can result in AKI. Several strategies including use of the monoclonoal antibody basilixamab to allow for delayed initiation of tacrolimus therapy and minimization through combination and minimization or elimination of TAC through combination with mycophenolate mofetil or mammalian target of rapamycin inhibitors have been implemented to reverse and avoid AKI in the post-LT setting. Renal replacement therapy may ultimately be required to support patients until recovery of AKI after LT. Overall, by improving renal function in post-LT patients with AKI, outcomes can be improved.

Hepatorenal syndrome: pathophysiology and evidence-based management update

Hepatorenal syndrome (HRS) is a functional renal failure that develops in patients with advanced hepatic cirrhosis with ascites and in those with fulminant hepatic failure. The prevalence of HRS varies among studies but in general it is the third most common cause of acute kidney injury (AKI) in cirrhotic patients after pre-renal azotemia and acute tubular necrosis. HRS carries a grim prognosis with a mortality rate approaching 90% three months after disease diagnosis. Fortunately, different strategies have been proven to be successful in preventing HRS. Although treatment options are available, they are not universally effective in restoring renal function but they might prolong survival long enough for liver transplantation, which is the ultimate treatment. Much has been learned in the last two decades regarding the pathophysiology and management of this disease which lead to notable evolution in the HRS definition and better understanding on how best to manage HRS patients. In the current review, we will summarize the recent advancement in epidemiology, pathophysiology, and management of HRS.

Clinical outcomes and prognostic factors of mortality in liver cirrhosis patients on continuous renal replacement therapy in two tertiary hospitals in Korea

Background

Data on liver cirrhosis (LC) patients undergoing continuous renal replacement therapy (CRRT) are lacking despite of the dismal prognosis. We therefore evaluated clinical characteristics and predictive factors related to mortality in LC patients undergoing CRRT.

Methods

We performed a retrospective observational study at two tertiary hospitals in Korea. A total of 229 LC patients who underwent CRRT were analyzed. Patients were classified into survivor and non-survivor groups. We used multivariable Cox regression analyses to identify predictive factors of in-hospital mortality.

Results

During a median follow-up of 5 days (interquartile range, 1-19 days), in-hospital mortality rate was 66.4%. In multivariable analysis, the Acute Physiology and Chronic Health Evaluation II (APACHE II) score (hazard ratio [HR], 1.03; 95% confidence interval [CI], 1.01-1.06; p = 0.02), Model for End-Stage Liver Disease (MELD) score (HR, 1.08; 95% CI, 1.04-1.11; p > 0.001), and delivered CRRT dose (HR, 0.95; 95% CI, 0.92-0.98; p = 0.002) were significant risk factors for in-hospital mortality. Patients with a CRRT delivered dose < 25 mL/kg/hr had a higher mortality rate than those with a delivered dose > 35 mL/kg/hr (HR, 3.13; 95% CI, 1.62-6.05; p = 0.001). Subgroup analysis revealed that a CRRT delivered dose > 25 mL/kg/hr was a significant risk factor for in-hospital mortality among LC patients with a MELD score ≥ 30.

Conclusion

High APACHE II score, high MELD score, and low delivered CRRT dose were significant risk factors for in-hospital mortality. CRRT delivered dose impacted mortality significantly, especially in patients with a MELD score ≥ 30.

Progression of Stage 2 and 3 Acute Kidney Injury in Patients With Decompensated Cirrhosis and Ascites

BACKGROUND & AIMS

Progression of stages 2 and 3 acute kidney injury (AKI) in cirrhosis has not been characterized adequately. Patients with higher stages of AKI are believed to have worse outcomes. We assessed outcomes and factors associated with stages 2 and 3 AKI in patients with cirrhosis in the North American Consortium for the Study of End-stage Liver Disease cohort.

METHODS

We collected data from 2297 hospitalized patients with cirrhosis and ascites from December 2011 through February 2017. Our final analysis included 760 patients who developed AKI per the International Ascites Club 2015 definition (419 with maximum stage 1 and 341 with maximum stage 2 or 3; 63% male; mean age, 58 y). We compared demographic features, laboratory values, AKI treatment response, and survival between patients with maximum stage 1 vs patients with stage 2 or 3 AKI.

RESULTS

Patients with stage 2 or 3 AKI had higher Model for End-Stage Liver Disease scores (25.9 ± 7.3) than patients with stage 1 AKI (21.9 ± 7.5) (P < .0001). More patients fulfilled systemic inflammatory response syndrome criteria on admission, and more developed a second nosocomial infection (P < .05 for both comparisons). More patients with stage 2 or 3 AKI also had progression of AKI and required dialysis and admission into intensive care units when compared to stage 1 AKI patients (P < .0001 for both). A lower proportion of patients with stage 2 or 3 AKI survived their hospital stay (80% vs 99% with stage 1 AKI; P < .0001), or survived for 30 days without a liver transplant (56% vs 81%; P < .0001). The development of stage 2 or 3 AKI was associated with a higher Model for End-Stage Liver Disease score at the time of admission (P < .0001), presence of systemic inflammatory response on admission (P = .039), and second infection (P < .0001).

CONCLUSIONS

Based on an analysis of data from the North American Consortium for the Study of End-stage Liver Disease cohort, we found that patients with cirrhosis and more advanced liver disease, as well as a second infection, are more likely to develop stages 2 or 3 AKI, with a progressive course associated with decreased 30-day transplant-free survival. Prevention of AKI progression in patients with cirrhosis and stage 2 or 3 AKI might improve their outcomes.

Advances in management of hepatorenal syndrome

PURPOSE OF REVIEW

Hepatorenal syndrome (HRS) is encountered frequently in patients with end-stage liver disease and remains an important cause of morbidity and mortality in this patient population. This review will focus and provide updates on pathophysiology, assessment of kidney function, new definitions, and treatment and prevention of HRS.

RECENT FINDINGS

Pathophysiology of HRS has been elucidated more recently and in addition to hemodynamic changes, the role of systemic inflammatory response contributes significantly to this process. Assessment of kidney function in patients with liver cirrhosis remains challenging. Novel glomerular filtration rate equations have been developed in patients with liver disease to better estimate kidney function and changes made in the definition of acute kidney injury (AKI), which are more aligned with KDIGO criteria for AKI. Vasoconstrictors, especially terlipressin, along with albumin remain the mainstay of pharmacological treatment of HRS-AKI. Biomarkers have been useful in differentiating ATN from HRS at an early stage.

SUMMARY

HRS remains a significant cause of morbidity and mortality for patients with end-stage liver disease. Newer understanding of mechanisms in development and pathophysiology of HRS have helped with elucidation of the disease process.

Hillien SA, Kalim S, Nigwekar SU, Flood JG, Nixon A, Simonetto DA, Juncos LA, Karakala N, Wadei HM, Regner KR, Belcher JM, Nadim MK, Garcia-Tsao G, Velez JCQ, Parikh SM, Chung RT. Urinary NGAL as a Diagnostic and Prognostic Marker for Acute Kidney Injury in Cirrhosis: A Prospective Study

INTRODUCTION

Urinary neutrophil gelatinase-associated lipocalin (NGAL) has shown promise in differentiating acute tubular necrosis (ATN) from other types of acute kidney injuries (AKIs) in cirrhosis, particularly hepatorenal syndrome (HRS). However, NGAL is not currently available in clinical practice in North America.

METHODS

Urinary NGAL was measured in a prospective cohort of 213 US hospitalized patients with decompensated cirrhosis (161 with AKI and 52 reference patients without AKI). NGAL was assessed for its ability to discriminate ATN from non-ATN AKI and to predict 90-day outcomes.

RESULTS

Among patients with AKI, 57 (35%) had prerenal AKI, 55 (34%) had HRS, and 49 (30%) had ATN, with a median serum creatinine of 2.0 (interquartile range 1.5, 3.0) mg/dL at enrollment. At an optimal cutpoint of 244 μg/g creatinine, NGAL distinguished ATN (344 [132, 1,429] μg/g creatinine) from prerenal AKI (45 [0, 154] μg/g) or HRS (110 [50, 393] μg/g; P < 0.001), with a C statistic of 0.762 (95% confidence interval 0.682, 0.842). By 90 days, 71 of 213 patients (33%) died. Higher median NGAL was associated with death (159 [50, 865] vs 58 [0, 191] μg/g; P < 0.001). In adjusted and unadjusted analysis, NGAL significantly predicted 90-day transplant-free survival (P < 0.05 for all Cox models) and outperformed Model for End-Stage Liver Disease score by C statistic (0.697 vs 0.686; P = 0.04), net reclassification index (37%; P = 0.008), and integrated discrimination increment (2.7%; P = 0.02).

DISCUSSION

NGAL differentiates the type of AKI in cirrhosis and may improve prediction of mortality; therefore, it holds potential to affect management of AKI in cirrhosis.

Monitoring Renal Function and Therapy of Hepatorenal Syndrome Patients with Cirrhosis

Acute kidney injury (AKI) is a frequent complication in patients with cirrhosis. Patients with cirrhosis can develop AKI due to different causes. Hepatorenal syndrome (HRS) is a unique cause of AKI occurring in patients with advanced cirrhosis and is associated with high short-term mortality. The differential diagnosis between different causes of AKI may be challenging. In this regard, new urine biomarkers may be helpful. Liver transplantation is the definitive treatment of patients with HRS-AKI. Vasoconstrictors and albumin represent the first-line pharmacologic treatment of HRS-AKI. This review summarizes current knowledge for the diagnosis and management of HRS in cirrhosis.

Global strategy for the diagnosis and management of acute kidney injury in patients with liver cirrhosis

Acute kidney injury (AKI) is a clinical syndrome that complicates the course and worsens clinical outcomes in patients with chronic liver diseases. It is a common complication in hospitalised patients with liver cirrhosis, especially those with decompensated cirrhosis, associated with a high mortality rate. Considering its impact on patient prognosis, efforts should be made to diagnose and tailor therapeutic interventions for AKI at an early stage. In the past decade, a significant progress has been made to understand the key events and define major prognostic factors for the onset and progression of AKI in the cirrhotic population leading hepatologists to redefine the classic definition of hepatorenal syndrome and renal failure in this specific population.

Reduction in acute kidney injury stage predicts survival in patients with type-1 hepatorenal syndrome

Background

Hepatorenal syndrome type 1 (HRS-1), a form of acute kidney injury (AKI) in cirrhosis, has a median survival of days to weeks if untreated. The impact of reduction in AKI stage on overall survival in cirrhosis, independent of HRS reversal, is unclear.

Methods

The Randomized, placEbo-controlled, double-blind study to confirm the reVERSal of HRS-1 with terlipressin study assessed terlipressin versus placebo, both with albumin, as treatment for HRS-1 for ≤14 days. Renal dysfunction severity was categorized by AKI stage at enrollment. Baseline patient characteristics were evaluated as predictors of AKI improvement using a multivariate model; the association between AKI stage reduction and 90-day survival was assessed using linear regression.

Results

A total of 184 patients (terlipressin: n = 91; placebo: n = 93) with similar numbers in AKI Stages 1–3 (terlipressin/placebo, Stage 1: n = 25/26; Stage 2: n = 35/33; Stage 3: n = 31/34) were included. Predictors of AKI improvement were absence of alcoholic hepatitis, baseline serum creatinine and male gender. Overall survival was not significantly different across AKI stages (range 53–65%). In patients with no AKI worsening, 90-day survival was consistently better when AKI improved independent of HRS reversal, regardless of the initial AKI stage, with patients with Stage 1 at initial diagnosis achieving the greatest clinical benefit. A significant association was observed between AKI reduction and overall 90-day survival (P = 0.0022).

Conclusions

A reduction in AKI stage, independent of HRS reversal, was sufficient to improve overall survival in patients with HRS-1. The goal for HRS-1 treatment should be less stringent than absolute HRS reversal.

Hepatorenal Syndrome

Development of acute kidney injury in patients with chronic liver disease is common and portends a poor prognosis. Diagnosis remains challenging, as traditional markers, such as serum creatinine, are not reliable. Recent development of novel biomarkers may assist with this. Pathophysiology of this condition is multifactorial, relating to physiologic changes associated with portal hypertension, kidney factors, and systemic inflammatory response. Mainstay of treatment remains use of vasoconstrictors along with albumin. Recent guidelines streamline the selection of patients that will require simultaneous liver and kidney transplantation. Posttransplant kidney injury is common relating to multiple factors.

Prognosis predictability of serum and urine renal markers in patients with decompensated cirrhosis: A multicentre prospective study

BACKGROUND AND AIMS

This prospective observational study aimed to evaluate the best serum and urine markers to assess predictability for the prognosis of patients with decompensated cirrhosis.

METHODS

Serum creatinine and cystatin C (CysC), and urinary N-acetyl-beta-D glucosaminidase (uNAG) and neutrophil gelatinase-associated lipocalin (uNGAL) levels were measured from hospitalized patients with decompensated cirrhosis.

RESULTS

In total, 328 patients (mean age, 57.2 ± 12.0 years; 237 men) with decompensated cirrhosis were included. Alcoholic liver disease was the most frequent underlying liver disease (68.0%). Acute kidney injury (AKI) was concomitantly present in 41 patients (12.5%) at baseline. INR, serum creatinine and CysC levels, and uNAG and uNGAL levels were significantly higher in patients with AKI. During hospitalization, AKI had progressed in 37 patients (11.3%). In 287 patients without AKI, the incidence of AKI at 3, 6, 9 and 12 months was 15.4%, 22.2%, 28.6% and 32.5% respectively. On multivariate analysis, serum CysC and uNAG levels were independent predictors of AKI, and their optimal cut-off values were 1.055 mg/L and 23.1 U/g urinary Cr respectively. When patients were classified into three groups with these cut-off values of serum CysC and uNAG levels (group 1, both low; group 2, one of two high; and group 3, both high), progression of AKI during hospitalization (P = .001), incidence of AKI in patients without AKI at baseline (P = .001) and mortality rate (P < .001) differed significantly according to serum CysC and uNAG levels.

CONCLUSION

Serum CysC and uNAG levels are useful prognostic markers for renal outcomes and mortality in patients with decompensated cirrhosis.

IMPACT OF ACUTE KIDNEY INJURY STAGING ON PROGNOSIS OF PATIENTS WITH CIRRHOSIS

BACKGROUND

Acute kidney injury (AKI) is a common and severe complication of cirrhosis.

OBJECTIVE

To evaluate the impact of AKI staging on 30-day mortality of patients with cirrhosis.

METHODS

We performed a retrospective cohort study of hospitalized patients with cirrhosis. Acute kidney injury (AKI) was diagnosed according to the International Club of Ascites recommendations and staged according to the European Association for the Study of the Liver guidelines. Comparisons between groups were made by one-way analysis of variance and Tukey test. Chi-square was calculated for dichotomous variables. Comparisons of renal impairment status among patients were performed using Kaplan-Meier statistics and differences between groups were analyzed using the log-rank test. A P-value <0.05 was considered to be statistically significant.

RESULTS

Two hundred and thirty-two patients were included in the study. The diagnosis of AKI was performed in 98 (42.2%) of them. The overall 30-day mortality was 19.8% (46/232). Mortality increased as the degree of AKI progressed. Among patients who did not have AKI, mortality was 5.2% (7/134). When compared to patients without AKI, patients diagnosed with AKI stage 1a had mortality of 12.1% (4/33, P=0.152); patients with AKI stage 1b had mortality of 45% (18/40, P<0.001); and patients with AKI stages 2 or 3 had mortality of 68% (17/25, P<0.001). Moreover, it is noteworthy that full response to treatment was associated to a decreased mortality when compared to patients who did not show complete recovery of renal function (14.3% vs 57.9%, P<0.001).

CONCLUSION

AKI stages 1b or greater, but not AKI stage 1a, are associated to higher 30-day mortality of patients with cirrhosis.

Prerenal acute kidney injury—still a relevant term in modern clinical practice?

The traditional taxonomy of acute kidney injury (AKI) has remained pervasive in clinical nephrology. While the terms ‘prerenal’, ‘intrarenal’ and ‘postrenal’ highlight the diverse pathophysiology underlying AKI, they also imply discrete disease pathways and de-emphasize the nature of AKI as an evolving clinical syndrome with multiple, often simultaneous and overlapping, causes. In a similar vein, prerenal AKI comprises a diverse spectrum of kidney disorders, albeit one that is often managed by using a standardized clinical algorithm. We contend that the term ‘prerenal’ is too vague to adequately convey our current understanding of hypoperfusion-related AKI and that it should thus be avoided in the clinical setting. Practice patterns among nephrologists indicate that AKI-related terminology plays a significant role in the approaches that clinicians take to patients that have this complex disease. Thus, it appears that precise terminology does impact the treatment that patients receive. We will outline differences in the diagnosis and management of clinical conditions lying on the so-called prerenal disease spectrum to advocate caution when administering intravenous fluids to these clinically decompensated patients. An understanding of the underlying pathophysiology may, thus, avert clinical missteps such as fluid and vasopressor mismanagement in tenuous or critically ill patients.

Incidence, Mortality and Predictors of Acute Kidney Injury in Patients with Cirrhosis: A Systematic Review and Meta-analysis

Background and Aims: Acute kidney injury (AKI) is common in patients with cirrhosis but the incidence is heterogeneous among studies. We performed a meta-analysis to describe the incidence of AKI and its impact on patient mortality in patients with cirrhosis. We also evaluated the admission variables predicting development of AKI. Methods: A systematic search of various databases was performed up to November 2018. Meta-analyses were performed using random effects models. Results: Of 18,474 patients with cirrhosis from 30 selected studies, 5,648 developed AKI, with a pooled incidence of 29% (95% confidence interval [CI]: 28-30%, I ² of 99%). In-hospital mortality assessed in eight studies was six-fold higher among AKI patients, as compared to those without AKI (odds ratio [OR] 6.72, 95% CI: 3.47-13, p<0.0001, I ² of 70%). Three studies on patients admitted to intensive care showed about six-fold higher mortality among AKI patients (OR 5.90, 95% CI: 3.21-10.85, p>0.0001). Mortality remained significantly high, at days 30 and 90 and even at 1-year follow up after development of AKI. Of 12 admission variables analyzed, model for end-stage liver disease score, Child-Pugh-Turcotte stage C, presence of ascites, and presence of sepsis/septic shock were statistically significant risk factors for AKI. Conclusions: AKI occurred in about 29% of patients with cirrhosis and is associated with a six-fold increased risk of in-hospital mortality. Mortality remained high even in long-term follow-up of 1 year. Patients at risk for AKI development can be recognized at admission. Prospective studies are needed to develop strategies for improving outcome of these patients.

Management of Hepatorenal Syndrome: A Review

Acute kidney injury (AKI) occurs frequently in patients with cirrhosis, and hepatorenal syndrome (HRS) is second most common etiology of AKI after volume responsible pre-renal etiology. AKI in these patients negatively impacts pre- and post-transplant patient survival and healthcare burden. Reduced effective blood volume with consequent reduced renal blood flow, along with systemic inflammation in patients with decompensated cirrhosis, result in susceptibility to HRS. In this article, we will review updates over the last 5 years on the changing definition with diagnostic criteria and nomenclature of AKI and HRS, data on medical treatment with vasoconstrictors, and urinary biomarkers in diagnosis of etiology of AKI. We will also discuss the significance of liver transplantation evaluation once the diagnosis of HRS is established and the post-transplant immunosuppression management. We will also review one of the challenging issues that remains among transplant-eligible patients, that of allocation of simultaneous liver kidney transplant. Finally, we will review the new implemented policy from the Organ Procurement Transplant Network on simultaneous liver kidney allocation.

Acute kidney injury in cirrhosis: implications for liver transplantation

PURPOSE OF REVIEW

Acute kidney injury (AKI) in cirrhosis consists of varying phenotypes, with hepatorenal syndrome (HRS) representing a single entity. Prompt recognition and diagnosis of AKI cause identifies appropriate therapeutic measures. This review provides an overview of AKI definitions, highlights challenges in quantifying renal impairment in cirrhosis, lists novel diagnostic AKI biomarkers, and summarizes transplantation implications.

RECENT FINDINGS

Biomarkers (neutrophil gelatinase-associated lipocalin, kidney injury molecule-1, interleukin-18, and liver-type fatty acid-binding protein) may assist in the identification of underlying acute tubular necrosis. Of these, neutrophil gelatinase-associated lipocalin is the most promising; however, significant overlap occurs among AKI phenotypes, with diagnostic values yet to be defined. Mainstay treatment of HRS consists of albumin and vasopressors. Acute-on-chronic liver failure grade independently predicts response to terlipressin treatment. Many end-stage liver disease patients with AKI have underlying chronic kidney disease with important implications on pre and postliver transplantation mortality. Simultaneous liver-kidney transplant candidacy is based on low likelihood of renal recovery.

SUMMARY

Novel biomarkers may assist in identification of acute tubular necrosis and persistent/severe AKI. Norepinephrine has been suggested to be inferior to terlipressin, with additional research required. Increasing acute-on-chronic liver failure grade correlates with lower likelihood of vasopressor response in HRS. Severe preliver transplantation AKI confers significantly worse postliver transplantation renal outcomes.

Acute kidney injury: A critical care perspective for orthotopic liver transplantation

Acute kidney injury (AKI) is associated with high perioperative mortality in patients undergoing liver transplantation (LT). In the era of Model of End-stage Liver Disease score-based allocation, more patients with impaired renal function are receiving LT. The majority of preoperative AKI is secondary to azotemia, including hepatorenal syndrome - a progressive form of renal impairment unique to liver failure. Prompt recognition and initiation of cause-directed therapies are central to improving post-transplant survival. Given that, the healthcare providers must develop an expertise in liver failure-related renal complications, specifically their management and perioperative implications. Notably, AKI may complicate intraoperative course, exacerbating hemodynamic instability, metabolic acidosis, and electrolyte and coagulation abnormalities. Adjunctive intraoperative continuous renal replacement therapy has been employed; however, prospective studies remain necessary to validate potential benefits.

Neutrophil Gelatinase-Associated Lipocalin for Assessment of Acute Kidney Injury in Cirrhosis: A Prospective Study

Kidney biomarkers appear to be useful in differential diagnosis between acute tubular necrosis (ATN) and other types of acute kidney injury (AKI) in cirrhosis, particularly hepatorenal syndrome (HRS-AKI). Distinction is important because treatment is different. However, kidney biomarkers are still not used in clinical practice. The aim of the current study was to investigate the accuracy of several biomarkers in differential diagnosis of AKI and in predicting kidney outcome and patient survival. This was a prospective study of 320 consecutive cases of AKI in patients hospitalized for decompensated cirrhosis. Evaluation of AKI was made with a diagnostic algorithm that included identification and removal/treatment of precipitating factors and albumin administration (1 g/kg for 2 days) to patients with AKI stage 1B or greater. Urinary neutrophil gelatinase-associated lipocalin (NGAL), monomeric NGAL (mNGAL), interleukin-18, and standard biomarkers were measured at diagnosis and on days 3, 7, and 14. Of the 320 cases, 153 were hypovolemia-induced AKI (48%), 93 were HRS-AKI (29%), 39 were ATN (12%), and 35 were due to miscellaneous causes (11%). Among all biomarkers, urinary NGAL measured at day 3 had the greatest accuracy for differential diagnosis between ATN and other types of AKI (area under the receiver operating characteristic curve, 0.87; 95% confidence interval, 0.78-0.95). The cutoff with the best predictive accuracy for ATN diagnosis was 220 µg/g creatinine. Progression of AKI during hospitalization was associated with persistently high NGAL levels, and NGAL was an independent predictive factor of AKI progression. Likewise, NGAL was also an independent predictive factor of 28-day mortality together with Model for End-Stage Liver Disease score. Conclusion: These results support the use of NGAL in clinical practice within the context of a diagnostic algorithm for differential diagnosis of AKI and outcome prediction in cirrhosis.

Hepatorenal Syndrome

Hepatorenal syndrome is a severe complication of end-stage cirrhosis characterized by increased splanchnic blood flow, hyperdynamic state, a state of decreased central volume, activation of vasoconstrictor systems, and extreme kidney vasoconstriction leading to decreased GFR. The contribution of systemic inflammation, a key feature of cirrhosis, in the development of hepatorenal syndrome has been highlighted in recent years. The mechanisms by which systemic inflammation precipitates kidney circulatory changes during hepatorenal syndrome need to be clarified. Early diagnosis is central in the management and recent changes in the definition of hepatorenal syndrome help identify patients at an earlier stage. Vasoconstrictive agents (terlipressin in particular) and albumin are the first-line treatment option. Several controlled studies proved that terlipressin is effective at reversing hepatorenal syndrome and may improve short-term survival. Not all patients are responders, and even in responders, early mortality rates are very high in the absence of liver transplantation. Liver transplantation is the only curative treatment of hepatorenal syndrome. In the long term, patients transplanted with hepatorenal syndrome tend to have lower GFR compared with patients without hepatorenal syndrome. Differentiating hepatorenal syndrome from acute tubular necrosis (ATN) is often a challenging yet important step because vasoconstrictors are not justified for the treatment of ATN. Hepatorenal syndrome and ATN may be considered as a continuum rather than distinct entities. Emerging biomarkers may help differentiate these two conditions and provide prognostic information on kidney recovery after liver transplantation, and potentially affect the decision for simultaneous liver-kidney transplantation.