Evaluation of the Acute Kidney Injury Network criteria in hospitalized patients with cirrhosis and ascites

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.

Ascites and Hepatorenal Syndrome

Ascites occurs in up to 70% of patients during the natural history of cirrhosis. Management of uncomplicated ascites includes sodium restriction and diuretic therapy, whereas that for refractory ascites (RA) is regular large-volume paracentesis with transjugular intrahepatic portosystemic shunt being offered in appropriate patients. Renal impairment occurs in up to 50% of patients with RA with type 1 hepatorenal syndrome (HRS) being most severe. Liver transplant remains the definitive treatment of eligible candidates with HRS, whereas combined liver and kidney transplant should be considered in patients requiring dialysis for more than 4 to 6 weeks or those with underlying chronic kidney disease.

News in pathophysiology, definition and classification of hepatorenal syndrome: A step beyond the International Club of Ascites (ICA) consensus document

Renal dysfunction is a common, life-threatening complication occurring in patients with liver disease. Hepatorenal syndrome (HRS) has been defined as a purely "functional" type of renal failure that often occurs in patients with cirrhosis in the setting of marked abnormalities in arterial circulation, as well as overactivity of the endogenous vasoactive systems.^4,5 In 2007, the International Club of Ascites (ICA) classified HRS into types 1 and 2 (HRS-1 and HRS-2).⁵ HRS-1 is characterised by a rapid deterioration of renal function that often occurs because of a precipitating event, while HRS-2 is a moderate and stable or slowly progressive renal dysfunction that often occurs without an obvious precipitant. Clinically, HRS-1 is characterised by acute renal failure while HRS-2 is mainly characterised by refractory ascites. Nevertheless, after these two entities were first described, new concepts, definitions, and diagnostic criteria have been developed by nephrologists for renal dysfunction in the general population and hospitalised patients. In particular, the definitions and characterisation of acute kidney injury (AKI), acute kidney disease and chronic kidney disease have been introduced/refined.⁶ Accordingly, a debate among hepatologists of the ICA led to a complete revision of the nomenclature and diagnosistic criteria for HRS-1, which was renamed HRS-AKI.⁷ Additionally, over recent years, greater granularity has been gained regarding the pathogenesis of HRS; it is now increasingly recognised that it is not a purely "functional" entity with haemodynamic derangements, but that systemic inflammation, oxidative stress and bile salt-related tubular damage may contribute significantly to its development. That is, HRS has an additional structural component that would not only make traditional diagnostic criteria less reliable, but would explain the lack of response to pharmacological treatment with vasoconstrictors plus albumin that correlates with a progressive increase in inflammation. Because classification, nomenclature, diagnostic criteria and pathogenic theories have evolved over the years since the traditional classification of HRS-1 and HRS-2 was first described, it was considered that all these novel aspects be reviewed and summarised in a position paper. The aim of this position paper authored by two hepatologists (members of ICA) and two nephrologists involved in the study of renal dysfunction in cirrhosis, is to complete the re-classification of HRS initiated by the ICA in 2012 and to provide an update on the definition, classification, diagnosis, pathophysiology and treatment of HRS.

Continuous terlipressin infusion is associated with improved diet intake and muscle strength in patients awaiting liver transplant

BACKGROUND & AIMS

Portal hypertension contributes to the pathogenesis of malnutrition and sarcopenia in cirrhosis via multiple mechanisms. Terlipressin is a vasopressin analogue that we administer via continuous outpatient infusion, as a bridge to transplantation in patients with hepatorenal syndrome or refractory ascites. We describe, for the first time, the impact of outpatient terlipressin on nutritional and muscle parameters.

METHODS

Nutrition (subjective global assessment), handgrip strength, dietary intake (energy, protein), frequency of paracentesis and severity of liver disease (model for end-stage liver disease score) were prospectively recorded at terlipressin commencement and follow-up (transplantation, cessation or census date).

RESULTS

Nineteen patients were included (89% male, median age 59.6 years, median model for end-stage liver disease score 24), of whom 12 had hepatorenal syndrome and 7 had refractory ascites. All patients were malnourished at baseline, 63% (n = 12) had sarcopenic-range grip strength, and mean paracentesis frequency was 2.86 ± 1.62/month. Median duration of terlipressin was 51 days (interquartile range 29-222). Fourteen patients (74%) were transplanted, 2 delisted (10%) and 3 (16%) continued terlipressin. Energy and protein intake improved significantly following terlipressin, from 17.94 ± 5.43 kcal/kg to 27.70 ± 7.48 kcal/kg, and 0.74 ± 0.28 g/kg to 1.16 ± 0.31 g/kg, respectively (both p < 0.001). Handgrip strength increased from 25.36 ± 8.13 kg to 28.49 ± 7.63 kg (p = 0.001). Linear regression analysis demonstrated hand grip strength increased 0.075% for every 1-day of terlipressin (p = 0.005). The frequency of large-volume paracentesis reduced by 46%, to 1.57 ± 1.51/month (p = 0.001).

CONCLUSION

Continuous terlipressin infusion reduces the complications of portal hypertension and is associated with an improvement in nutritional and muscle parameters in patients on the liver transplant waiting list, in whom such characteristics usually demonstrate progressive decline. This validates both the aetiological role of portal hypertension in malnutrition and represents a promising new anabolic therapy.

LAY SUMMARY

Malnutrition and poor muscle strength are common in liver disease and often get worse while patients await liver transplant. Terlipressin is a medication used to treat portal hypertension in patients with hepatorenal syndrome. It is usually given for a few days or weeks in patients confined to hospital. Our centre provides outpatient terlipressin for weeks to months as a bridge to liver transplant. In patients treated with terlipressin at our hospital, we observed a substantial increase in their dietary intake and muscle strength, which may improve their quality of life and outcomes after liver transplant.

Acute kidney injury spectrum in patients with chronic liver disease: Where do we stand?

Acute kidney injury (AKI) is a common complication of liver cirrhosis and is of the utmost clinical and prognostic relevance. Patients with cirrhosis, especially decompensated cirrhosis, are more prone to develop AKI than those without cirrhosis. The hepatorenal syndrome type of AKI (HRS–AKI), a spectrum of disorders in prerenal chronic liver disease, and acute tubular necrosis (ATN) are the two most common causes of AKI in patients with chronic liver disease and cirrhosis. Differentiating these conditions is essential due to the differences in treatment. Prerenal AKI, a more benign disorder, responds well to plasma volume expansion, while ATN requires more specific renal support and is associated with substantial mortality. HRS–AKI is a facet of these two conditions, which are characterized by a dysregulation of the immune response. Recently, there has been progress in better defining this clinical entity, and studies have begun to address optimal care. The present review synopsizes the current diagnostic criteria, pathophysiology, and treatment modalities of HRS–AKI and as well as AKI in other chronic liver diseases (non-HRS–AKI) so that early recognition of HRS–AKI and the appropriate management can be established.

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.

Biomarkers for acute kidney injury in decompensated cirrhosis: A prospective study

AIM

Acute kidney injury (AKI) is a frequent complication in cirrhotic patients. As serum creatinine is a poor marker of renal function in this population, we aimed to study the utility of several biomarkers in this context.

METHODS

A prospective study was conducted in hospitalized patients with decompensated cirrhosis. Serum creatinine (SCr), Cystatin C (CystC), NGAL and urinary NGAL, KIM-1, protein, albumin and sodium were measured on three separate occasions. Renal resistive index (RRI) was obtained. We analyzed the value of these biomarkers to determine the presence of AKI, its aetiology [prerenal, acute tubular necrosis (ATN), or hepatorenal (HRS)], its severity and a composite clinical outcome at 30 days (death, dialysis and intensive care admission).

RESULTS

We included 105 patients, of which 55 had AKI. SCr, CystC, NGAL (plasma and urinary), urinary sodium and RRI at inclusion were independently associated with the presence of AKI. SCr, CystC and plasma NGAL were able to predict the subsequent development of AKI. Pre-renal state showed lower levels of SCr, NGAL (plasma and urinary) and RRI. ATN patients had high levels of NGAL (plasma and urinary) as well as urinary protein and sodium. HRS patients presented an intermediate pattern. All biomarkers paralleled the severity of AKI. SCr, CystC and plasma NGAL predicted the development of the composite clinical outcome with the same performance as the MELD score.

CONCLUSIONS

In patients with decompensated cirrhosis, early measurement of renal biomarkers provides valuable information on AKI aetiology. It could also improve AKI diagnosis and prognosis.

Emerging Threat: Changing Epidemiology of Hepatitis A and Acute Kidney Injury

In the past decade, hepatitis A has been considered a rare disease in the United States, largely due to targeted vaccination of at-risk children. Evolving epidemiology has resulted in decreasing immunity and increasing hepatitis A infections among adults who are more likely to experience severe disease. A surge in outbreaks has been noted in the past 2 years, resulting in a high volume of hepatitis A related hospitalizations and complications in otherwise healthy individuals. The traditional understanding that acute kidney injury is a rare extrahepatic manifestation is being challenged by the resurgence of hepatitis A in a more vulnerable population. This review examines the epidemiologic factors that contributed to current public health concern and the association between hepatitis A and acute kidney injury.

Estimation of renal function in patients with liver cirrhosis: Impact of muscle mass and sex

BACKGROUND & AIMS

Accurate evaluation of renal function in patients with liver cirrhosis is critical for clinical management. However, there are still discrepancies between the measured glomerular filtration rate (mGFR) and creatinine-based estimated GFR (eGFR). In this study, we compared the performance of 2 common eGFR measurements with mGFR and evaluated the impact of low muscle mass on overestimation of renal function in patients with cirrhosis.

METHODS

This study included 779 consecutive cirrhotic patients who underwent ⁵¹Cr-ethylenediamine tetra acetic acid (EDTA) (as a mGFR) and abdominal computed tomography (CT). The eGFR was calculated using creatinine or cystatin C. Muscle mass was assessed in terms of the total skeletal muscle at L3 level using CT.

RESULTS

Modification of diet in renal disease (MDRD)-eGFR was overestimated in 47% of patients. A multivariate analysis showed that female sex (adjusted odds ratio [aOR] 4.91), Child B and C vs. A (aOR 1.69 and 1.84) and skeletal muscle mass (aOR 0.89) were independent risk factors associated with overestimation. Interestingly, the effect of skeletal muscle mass on overestimation varied based on sex. Decreased muscle mass significantly enhanced the risk of overestimation of MDRD-eGFR in male patients, but not in female patients. Cystatin C-based eGFR showed a better correlation with mGFR than MDRD-eGFR; it was also better at predicting overall survival and the incidence of acute kidney injury than MDRD-eGFR.

CONCLUSIONS

The risk factors associated with overestimation included female sex, impaired liver function, and decreased muscle mass in males. In particular, eGFR in male patients with sarcopenia should be carefully interpreted. Creatinine-based eGFR was overestimated more often than cystatin C-based eGFR, with overestimation of eGFR closely related to poor prognostic performance.

LAY SUMMARY

Overestimation of renal function frequently occurs in patients with liver cirrhosis when using serum creatinine. Decreased muscle mass has a great impact on overestimation of kidney function especially in male patients with cirrhosis. Compared with creatinine, cystatin C was more closely correlated with measured glomerular filtration rate and had a higher predictive ability for renal complications and survival than creatinine.

Clinical Aspects and Prognosis Evaluation of Cirrhotic Patients Hospitalized with Acute Kidney Injury

BACKGROUND

Acute kidney injury occurs in approximately 20% of hospitalized cirrhotic patients. Mortality is estimated at 60% within a month and 65% within a year.

AIMS

To evaluate survival in 30 days and in 3 months of cirrhotic patients hospitalized with acute kidney injury, identifying factors associated with mortality.

METHODS

52 patients with cirrhosis admitted to an academic tertiary center who presented acute kidney injury according to the International Club of Ascites criteria were evaluated. Clinical and laboratory data was collected at diagnosis between 2011 and 2015.

RESULTS

Average age was 54.6 (±10.7) years and 69.2% were male. The average MELD, MELD-Na, and Child-Pugh scores were 21.9 (±7.0), 24.5 (±6.7), and 10.1 (±2.2), respectively. Thirty patients (57.7%) were in acute kidney injury stage 1, 16 (30.8%) in stage 2, and six (11.6%) in stage 3. Mortality was 28.6% in 30 days and 44.9% in three months. In multivariate analysis, variables that were associated independently to mortality were lack of response to expansion treatment and Child-Pugh score. Mortality was 93.3% in three months among nonresponders compared to 28.6% among those who responded to volume expansion (p<0.0001).

CONCLUSION

Acute kidney injury in cirrhosis has dire prognosis, particularly in patients with advanced cirrhosis and in nonresponders to volume expansion.

Validation of International Club of Ascites subclassification of stage 1 acute kidney injury in chronic liver disease

Background and Aim

Acute kidney injury (AKI) commonly occurs in patients with chronic liver disease (CLD). As per the International Club of Ascites, AKI is classified into three stages; stage 1 has recently been divided into subgroups 1A and 1B. We performed a prospective study to validate the association between subgrouping and outcome.

Methods

This study was conducted using decompensated cirrhosis (DC) patients hospitalized in the Gastroenterology ward between August 2016 and May 2018. Demographic, clinical, and laboratory parameters were compared between AKI 1A and AKI 1B patients. The duration of hospitalization and outcome were compared.

Results

A total of 528 subjects were enrolled; 296 (56.1%) had AKI, and of them, 61.48% (n = 182) had stage 1, 20.95% (n = 62) had stage 2, and 17.57% (n = 52) had stage 3 AKI. Of the enrolled patients, 100 (54.94%) had early (AKI 1A) and 82 (45.06%) had late stage 1 AKI (AKI 1B). Patients with AKI 1B had higher total leucocyte count, total bilirubin, serum urea, serum creatinine (SCr), model for end‐stage liver disease (MELD), MELD‐Na⁺, and child‐turcotte‐pugh (CTP) score and decreased serum albumin than AKI 1A. The prevalence of hepatorenal syndrome (HRS), acute on chronic liver failure (ACLF) were higher in AKI 1B patients, and they had a prolonged hospital stay compared to AKI 1A patients. Furthermore, AKI 1B patients had significantly lower survival both at 28 days and 90 days.

Conclusion

Our study validates the subclassification of stage 1 AKI. Patients with AKI 1B more often progress to higher AKI stages with significantly lower 28‐day and 90‐day survival rates. Results justify subclassification and suggest the need for early intervention. The small increase in SCr should be viewed with caution in AKI stage 1A.

Renal impairment is associated with increased risk of mortality in patients with cirrhosis: A retrospective cohort study

Although renal impairment is a frequent complication in cirrhosis that is associated with a poor prognosis, little has been reported on the clinical significance of renal impairment in cirrhosis in Japan. This retrospective study assessed the impact of renal impairment on mortality in Japanese cirrhosis patients taking conventional diuretics.A total of 157 patients with cirrhosis receiving diuretic treatment were evaluated for the presence and status of renal impairment, defined as an increase in serum creatinine of ≥ 0.3 mg/dL or by ≥ 50%, and then classified according to the International Club of Ascites (ICA)-Acute Kidney Injury (AKI) staging system.Eighty of 157 (51%) patients fulfilled the criteria for renal impairment. Thirty-four (43%) patients had ICA-AKI stage 1, 32 (40%) stage 2, and 14 (18%) stage 3. Multivariate analysis revealed female gender (hazard ratio [HR] = 0.407, 95% confidence interval = 0.193-0.857; P = .018), ALT ≥35 IU/L (HR = 3.841, 95% confidence interval = 1.785-8.065; P = .001), and the presence of renal impairment (HR = 4.275, 95% confidence interval = 1.962-9.312; P < .001) as independent factors significantly increasing the risk of mortality. Cumulative survival rates increased significantly with ICA-AKI stage (log-rank test, P = .009).Renal impairment was a predictive marker of mortality in Japanese patients with cirrhosis. Stratification according to ICA-AKI criteria of kidney function impairment may be a good prognostic indicator of cirrhosis outcome.

Acute Kidney Injury at Admission Is a Better Predictor of Mortality than Its Persistence at 48 h in Patients with Acute-on-chronic Liver Failure

Background and Aims: Acute kidney injury (AKI) occurs commonly in patients with acute-on-chronic liver failure (ACLF). However, there are scant data regarding the impact of AKI on survival in ACLF. We performed a prospective study to evaluate the impact of AKI on survival in ACLF.

Methods: This study was conducted in ACLF patients hospitalized in the Gastroenterology Department of Sriram Chandra Bhanja Medical College (India) between October 2016 and February 2018. Demographic, clinical and laboratory parameters were recorded, and outcomes were compared between patients with and without AKI and between patients with persistent AKI and AKI reversal at 48 h.

Results: We screened 439 chronic liver disease patients as per the Asian Pacific Association for the Study of the Liver criteria and found that 113 (25.7%) of them had ACLF and 78 (69%) of them had AKI as per the Acute Kidney Injury Network criteria. ACLF patients with AKI had reduced 28-day survival (44.9% vs. 74.3%; p = 0.004) and 90-day survival (25.6% vs. 51.4%; p = 0.007), in comparison to ACLF patients without AKI. However, when comparison was made between AKI reverters and AKI persisters at 48 h, survival was comparable for both at 28 days and 90 days. Further, about one-tenth of ACLF patients with AKI died within 48 h of hospitalization.

Conclusions: Over two-thirds of ACLF patients had AKI. Although ACLF itself is a predictor of reduced survival, a very small increase in serum creatinine further worsens survival. Importantly, AKI at admission is a better predictor of early mortality in ACLF patients since recovery from AKI at 48 h does not improve survival.

Presence of Sarcopenia and Its Rate of Change Are Independently Associated with Long-term Mortality in Patients with Liver Cirrhosis

BACKGROUND

Sarcopenia is associated with a poor prognosis in patients with liver cirrhosis. However, it is not known whether the rate of skeletal muscle depletion is also associated with a poor prognosis. We investigated the prognostic impact of the rate of skeletal muscle depletion in patients with liver cirrhosis.

METHODS

We included retrospectively all patients with liver cirrhosis who underwent both multiple computed tomography scans and hepatic venous pressure gradient (HVPG) measurements.

RESULTS

A total of 131 patients with liver cirrhosis were enrolled. The mean age of the patients was 53.7 years and alcoholic liver disease was the most common cause (61.8%). Sixty-four patients (48.9%) were diagnosed with sarcopenia. The median changes in skeletal muscle area per year (ΔSMA/y) were -0.89%. During a median follow-up period of 46.2 months (range, 3.4-87.6), 45 patients (34.4%) died. In multivariate analyses, age, Child-Pugh score, HVPG, presence of sarcopenia and ΔSMA/y were independently associated with mortality. Cumulative mortality was significantly higher in patients with ΔSMA/y < -2.4% than those with ΔSMA/y ≥ -2.4% (log-rank test, P < 0.001).

CONCLUSION

Both the presence and rate of change of sarcopenia are independently associated with long-term mortality in patients with liver cirrhosis.

Evaluation of the criteria of hepatorenal syndrome type of acute kidney injury in patients with cirrhosis admitted to ICU

INTRODUCTION

Acute kidney injury (AKI) is a common and devastating complication in patients with cirrhosis. In 2015, the International Club of Ascites (ICA) proposed the definition of hepatorenal syndrome (HRS) type of AKI (HRS-AKI) in patients with cirrhosis. This study aims to evaluate the criteria of HRS-AKI in patients with cirrhosis admitted to ICU with regard to the prognosis.

METHODS

A total of 349 cirrhotic patients consecutively admitted to intensive care unit (ICU) from 2010 to 2017 were retrospectively analyzed. Demographic parameters and clinical variables were collected with case report forms. The occurrence of AKI was determined according to ICA-AKI criteria. The phenotypes of AKI comprised pre-renal azotemia (PRA), acute tubular necrosis (ATN) and HRS. In our study, patients with PRA or ATN were classified to the non-HRS-AKI group.

RESULTS

The incidence of AKI was 73.0%, comprising PRA (18.6%), ATN (16.3%) and HRS (38.1%). The overall hospital mortality was 64.5%. Patients with AKI had a significantly higher in-hospital (76.1%) and 180-d (86.7%) mortality. AKI type was an independent risk factor for in-hospital mortality by a multivariate logistic regression. The in-hospital and 180-d mortality rates were of no significant difference among patients with HRS-AKI stages 1-3.

CONCLUSIONS

AKI is common in patients with cirrhosis admitted to ICU, associated with significant in-hospital mortality. HRS-AKI was the most common and severe type of AKI in patients with cirrhosis admitted to ICU. The current staging system may not be applicable for HRS-AKI in patients with cirrhosis admitted to ICU.

Hepatorenal syndrome in the era of acute kidney injury

Acute kidney injury (AKI) is a frequent complication of patients with advanced cirrhosis that it is associated with increased hospital admissions and decreased survival. The definition of AKI in cirrhosis has been recently modified and the new diagnostic criteria are based on small changes in serum creatinine with respect to previous values, occurring within a short period of time. The use of this new definition may lead to an earlier identification of renal impairment and better prognostic stratification. Hepatorenal syndrome (HRS) is a unique form of AKI developing in patients with end-stage liver disease. Systemic circulatory dysfunction and marked kidney vasoconstriction play a key role in the development of HRS. The modification of the definition of AKI has also led to a change in the diagnostic criteria of HRS. The new diagnostic criteria are based on AKI stages and there is no need to reach a specific serum creatinine threshold. According to these new criteria, treatment with vasoconstrictors and albumin for the management of HRS will be started at lower serum creatinine values, with expected higher response rates. Finally, there are consistent data showing that some urine biomarkers, particularly NGAL (neutrophil gelatinase-associated lipocalin), may be useful in daily clinical practice for the differential diagnosis of the cause of AKI in cirrhosis.

"Normal" Creatinine Levels Predict Persistent Kidney Injury and Waitlist Mortality in Outpatients With Cirrhosis

Acute kidney injury (AKI) is a critical determinant of outcomes in hospitalized patients with cirrhosis, but little is known of the impact of AKI in the outpatient setting. We analyzed 385 adult outpatients with cirrhosis listed for liver transplant at a single center; excluded were those with severe hepatic encephalopathy, with hepatocellular carcinoma, or on hemodialysis. Baseline serum creatinine (bCr) was defined as the lowest value recorded, peak Cr as the highest value, ΔCr as peak Cr minus bCr, AKI as a rise in serum Cr (sCr) by ≥0.3 mg/dL from bCr, persistent kidney injury as elevation of sCR by ≥0.3 mg/dL from bCr on each subsequent clinical assessment. Among 385 outpatients with cirrhosis, bCr was ≤0.70, 0.70-0.97, and ≥0.97 mg/dL in 28%, 38%, and 34%, respectively. At a median follow-up of 16 (range 8-28) months, 143 (37%) had one or more AKI episode, which increased significantly by bCr group (24% versus 37% versus 48%, P = 0.001). Of these 143 with AKI, 13% developed persistent kidney injury. A multivariable Cox regression analysis highlighted that bCr (hazard ratio [HR], 2.96) and ΔCr (HR, 2.05) were the only factors independently associated with the development of persistent kidney injury (P < 0.001). The likelihood of death/delisting increased by bCr group (14% versus 19% versus 28%, P = 0.03). A competing risk analysis demonstrated that each 1 mg/dL increase in bCr was independently associated with a 62% higher risk of death/delisting when accounting for transplantation and adjusting for confounders. Conclusion: AKI is not only common in outpatients with cirrhosis but even "clinically normal" bCr levels significantly impact the risk of persistent kidney injury and waitlist mortality, supporting the need for a lower clinical threshold to initiate monitoring of renal function and implementation of kidney-protective strategies.

Risk factors, mortality and acute kidney injury outcomes in cirrhotic patients in the emergency department

Background

Acute kidney injury (AKI) is common in cirrhotic patients and is associated with negative outcomes. The aim of this study was to evaluate the presence of AKI and its progression according to KDIGO (Kidney Disease: Improving Global Outcomes) criteria in cirrhotic patients admitted to the emergency department and to determine the association of AKI with hospital mortality.

Methods

This retrospective study included 258 cirrhotic patients admitted to the emergency department of a university hospital from March 2015 to February 2017. AKI was diagnosed and classified according to the KDIGO criteria.

Results

The overall incidence of AKI in cirrhotic patients was 53.9%, and the overall hospital mortality was 28.4%. Mortality was associated with the presence, stage, and progression of AKI. Patients with AKI stage 1 and sCr < 1.5 mg/dl (KDIGO 1a) had a lower mortality rate than patients with AKI stage 1 and sCr > 1.5 mg/dl (KDIGO 1b). In the logistic regression analysis, three variables were independently associated with hospital mortality: cancer, AKI and progression of AKI.

Conclusions

According to the data presented, a single measure of creatinine is not enough, and there is a need for meticulous follow-up of the renal function of patients with hepatic cirrhosis hospitalized in an emergency unit. In addition, this study reinforces the need for subclassification of KDIGO 1 in cirrhotic patients, since patients with acute renal injury and creatinine greater than 1.5 mg/dL present a worse clinical outcome.

Hepatorenal syndrome

Hepatorenal syndrome (HRS) is a form of kidney function impairment that characteristically occurs in cirrhosis. Recent changes in terminology have led to acute HRS being referred to as acute kidney injury (AKI)-HRS and chronic HRS as chronic kidney disease (CKD)-HRS. AKI-HRS is characterized by a severe impairment of kidney function owing to vasoconstriction of the renal arteries in the absence of substantial abnormalities in kidney histology. Pathogenetic mechanisms involve disturbances in circulatory function due to a marked splanchnic arterial vasodilation, which triggers the activation of vasoconstrictor factors. An intense systemic inflammatory reaction that is characteristic of advanced cirrhosis may also be involved. The main triggering factors of AKI-HRS are bacterial infections, particularly spontaneous bacterial peritonitis. The diagnosis of AKI-HRS is a challenge because of a lack of specific diagnostic tools and mainly involves the differential diagnosis from other forms of AKI, particularly acute tubular necrosis. The prognosis of patients with AKI-HRS is poor, with a median survival of ≤3 months. The ideal treatment for AKI-HRS is liver transplantation in patients without contraindications. Medical therapy consists of vasoconstrictor drugs to counteract splanchnic arterial vasodilation together with volume expansion with albumin. Effective measures to prevent AKI-HRS include early identification and treatment of bacterial infections and the administration of albumin in patients with spontaneous bacterial peritonitis.

Renal Failure in Patients with Liver Cirrhosis: Novel Classifications, Biomarkers, Treatment

Renal failure is a severe complication in patients with liver cirrhosis. It is associated with increased mortality and morbidity. Diagnosis is a challenge because it is mainly based on serum creatinine, which does not seem to be an ideal measure of renal function in cirrhosis. The definition of renal failure in these patients has been changed for optimizing treatment and for improving outcome and prognosis. The new criteria are based on the adapted KDIGO (Kidney Disease: Improving Global Outcomes) staging system. The diagnosis of acute kidney injury (AKI) is based on an absolute increase of serum creatinine of >0.3 mg/dl from baseline within 48 h or an increase of >50% from baseline. This means smaller changes in serum creatinine in a shorter time frame which may lead to an early identification of renal failure in cirrhotic patients. The former cirrhotic-specific term hepatorenal syndrome (HRS) is now part of the new diagnostic criteria and is called HRS-AKI. The diagnostic criteria of HRS have changed due to the new criteria for AKI. Due to these criteria for HRS, the medical treatment will be started earlier. First-line treatment for renal AKI-HRS is the combination of a vasoconstrictor and albumin. Most data exist for terlipressin, a vasopressin analog, as vasoconstrictor. Besides this medical treatment, there are other options like the placement of a transjugular intrahepatic portosystemic shunt, renal replacement, and artificial extracorporeal liver support systems. However, these alternative treatment options have limitations. Liver transplantation is the treatment of choice for these patients and represents the definitive treatment. Using new biomarkers like urinary neutrophil gelatinase-associated lipocalin or interleukin-18 for renal failure in cirrhosis should help to differentiate the causes of renal failure and provide an indication regarding the prognosis.

Fractional excretion of urea: A simple tool for the differential diagnosis of acute kidney injury in cirrhosis

Current approaches to determine the cause of acute kidney injury (AKI) in patients with cirrhosis are suboptimal. The aim of this study was to determine the utility of fractional excretion of urea (FEUrea) for the differential diagnosis of AKI in patients with cirrhosis. A retrospective analysis was performed in patients (n = 50) with cirrhosis and ascites admitted with AKI. Using adjudicated etiology assessment as the reference standard, receiver operating curves and optimal cutoff, sensitivity (Sn), and specificity (Sp) for the diagnosis of prerenal azotemia (PRA), type 1 hepatorenal syndrome (HRS), and acute tubular necrosis (ATN) were derived. Validation was performed in an independent cohort (n = 50) and by bootstrap analysis. The causes of AKI (derivation:validation cohorts) were: PRA 21:21, HRS 18:15, and ATN 11:14. Median FEUrea was statistically different across all etiologies of AKI in the derivation cohort (PRA 30.1 vs. HRS 20.2 vs. ATN 43.6; P < 0.001) and validation cohort (PRA 23.1 vs. HRS 13.3 vs. ATN 44.7; P < 0.001). The area underneath the curve (cutoff, Sn/Sp) for FEUrea was 0.96 (33.4, 85/100) for ATN versus non-ATN, 0.87 (28.7, 75/83) for HRS versus non-HRS, and 0.81 (21.6, 90/61) for PRA versus HRS. When applied to the validation cohort, Sn/Sp were maintained for ATN versus non-ATN (93/97), HRS versus non-HRS (100/63), and for PRA versus HRS (67/80). After bootstrapping, Sn/Sp for FEUrea in the ATN versus non-ATN, HRS versus non-HRS, and PRA versus HRS was 88/96, 63/97, and 55/87, respectively.

CONCLUSION

FEUrea is a promising tool for the differential diagnosis of AKI in patients with cirrhosis. (Hepatology 2018;68:224-233).

RECOMMENDATIONS OF THE BRAZILIAN SOCIETY OF HEPATOLOGY FOR THE MANAGEMENT OF ACUTE KIDNEY INJURY IN PATIENTS WITH CIRRHOSIS

Acute kidney injury is a common complication of cirrhosis, occurring in up to 20% of patients hospitalized with cirrhosis. This field is rapidly changing, with significant advances in classification, biomarkers and therapy over the last few years. On the behalf of the Brazilian Society of Hepatology, a panel of experts in Hepatology and Nephrology reviewed published evidence to integrate findings and develop the recommendations presented in this manuscript.

Predictors of clinical outcomes in cirrhosis patients

PURPOSE OF REVIEW

The current review aims to explain the different systems available to clinicians for predicting clinical outcomes in patients with cirrhosis.

RECENT FINDINGS

Cirrhosis is the final stage of chronic liver disease and is associated with high morbidity and mortality. The most commonly utilized tools to predict outcomes in patients with cirrhosis include the following: assessing severity of portal hypertension using hepatic venous pressure gradient (HVPG) measurements, using scoring systems such as the Model for End-stage Liver Disease (MELD) and Child-Pugh-Turcotte (CPT) scores, and recently, clinical staging systems based on cirrhosis-related clinical complications. Assessing portal pressure with HVPG measurements provides valuable prognostic information, yet is costly, time-consuming, and invasive. MELD and CPT scores can be calculated quickly and not only assess liver function, but also yield predictive information. However, they represent only one point in time, and do not take into account the full clinical picture. Clinical staging systems have traditionally been focused on compensated and decompensated stages, with newer models assessing the influence of cirrhosis-related complications. However, these are not commonly utilized.

SUMMARY

Predicting clinical outcomes in patients with cirrhosis is challenging, and is likely best accomplished with a combination of objective data (such as MELD and HVPG provide) in addition to the clinical course of cirrhosis.

Prognostic Significance of The New Criteria for Acute Kidney Injury in Cirrhosis

BACKGROUND

New criteria for acute kidney injury (AKI) in cirrhosis have been proposed, but its prognostic significance is unclear. This study aims to evaluate the prognostic significance of the AKI criteria in cirrhotic patients hospitalized for acute decompensation.

MATERIAL AND METHODS

This is a prospective cohort study. AKI was defined as an increase in creatinine (Cr) levels ≥ 0.3 mg/dL in 48 h or ≥ 50% of the basal value in the last 7d. AKI was divided into stages 1 (elevation: < 2x basal), 2 (2 or 3x), and 3 (> 3x).

RESULTS

In this study, 227 patients aged 53.9 ± 11.5 years were included, of whom 37% had AKI (28% AKI1, 5% AKI2, and 4% AKI3). Thirty percent of the patients died or were transplanted within 90 days from causes related to the presence of ascites at hospital admission and higher values of Chronic Liver Failure-Sequential Organ Failure Assessment (CLIF-SOFA) scores, but not to the presence of AKI. In a regression analysis conducted to assess the effect of the final Cr level in patients with AKI, 90-day mortality was associated with ascites, higher CLIF-SOFA score, and AKI with final Cr level ≥ 1.5 mg/dL. The patients with AKI with Cr levels ≥ 1.5 mg/dL showed lower transplant-free survival rates than those without AKI, and those with AKI1 with final Cr level < 1.5 mg/dL.

CONCLUSIONS

Early AKI was frequent and associated with 90-day mortality or transplantation only when the final Cr level was ≥ 1.5 mg/dL. Distinct approaches are needed for patients with AKI1 according to final Cr.

Intensive Care Management of Patients with Cirrhosis

PURPOSE OF REVIEW

Cirrhosis is a major worldwide health problem which results in a high level of morbidity and mortality. Patients with cirrhosis who require intensive care support have high mortality rates of near 50%. The goal of this review is to address the management of common complications of cirrhosis in the ICU.

RECENT FINDINGS

Recent epidemiological studies have shown an increase in hospitalizations due to advanced liver disease with an associated increase in intensive care utilization. Given an increasing burden on the healthcare system, it is imperative that we strive to improve our management cirrhotic patients in the intensive care unit. Large studies evaluating the management of patients in the intensive care setting are lacking. To date, most recommendations are based on extrapolation of data from studies in cirrhosis outside of the ICU or by applying general critical care principles which may or may not be appropriate for the critically ill cirrhotic patient. Future research is required to answer important management questions.

Clinical states of cirrhosis and competing risks

The clinical course of cirrhosis is mostly determined by the progressive increase of portal hypertension, hyperdynamic circulation, bacterial translocation and activation of systemic inflammation. Different disease states, encompassing compensated and decompensated cirrhosis and a late decompensated state, are related to the progression of these mechanisms and may be recognised by haemodynamic or clinical characteristics. While these disease states do not follow a predictable sequence, they correspond to varying mortality risk. Acute-on-chronic liver failure may occur either in decompensated or in compensated cirrhosis and is always associated with a high short-term mortality. The increasing severity of these disease states prompted the concept of clinical states of cirrhosis. A multistate approach has been considered to describe the clinical course of the disease. Such an approach requires the assessment of the probabilities of different outcomes in each state, which compete with each other to occur first and mark the transition towards a different state. This requires the use of competing risks analysis, since the traditional Kaplan-Meier analysis should only be used in two-state settings. Accounting for competing risks also has implications for prognosis and treatment efficacy research. The aim of this review is to summarise relevant clinical states and to show examples of competing risks analysis in multistate models of cirrhosis.

Impact of Acute Kidney Injury on Mortality of Patients Hospitalized for Complications of Cirrhosis

BACKGROUND/AIMS

The mortality of hospitalized patients for complications of cirrhosis is very high. We examined the independent predictors of mortality, particularly the impact of increments in creatinine, in 339 consecutive patients (636 admissions) who were admitted for complications of cirrhosis.

METHODS

Clinical characteristics, biochemical parameters including serum creatinine levels at various time intervals, and mortality data were recorded for all admissions. Data were analyzed for initial as well for all repeated admissions to identify independent predictors of mortality.

RESULTS

The in-hospital mortality, 30-day, 90-day, 180 days, and 365 days mortality were 6%, 15%, 23%, 30%, and 41% respectively. Those admitted with spontaneous bacterial peritonitis had the worst survival. Increase in creatinine was noted in 29% of patients and they had lower 30-day (78% vs.91%) and 90-day (73% vs. 82%) survival than those without increase in creatinine. Any increment in serum creatinine (≥0.1 mg/dL) within 48 h after admission (peak 48 h - admission) was associated with a step-wise increase in mortality, but only if peak creatinine reached above 1.2 mg/dL. If peak creatinine levels were below 1.2 mg/dL, increases in serum creatinine had no impact on survival. Cox regression analysis showed that increments in serum creatinine of 0.3 mg/dL or higher had the worst outcome (HR 2.51, CI 1.65-3.81). Etiology of cirrhosis or the use of PPI, beta blockers or rifaxamin did not predict mortality. Other independent predictors of mortality were age, reason for admission, hyponatremia, and INR.

CONCLUSION

In patients with cirrhosis, any increment in serum creatinine within 48 h from hospitalization is associated with a higher mortality provided the peak serum creatinine within 48 h is above 1.2 mg/dL.

Acute kidney injury predicts mortality in cirrhotic patients with gastric variceal bleeding

BACKGROUND AND AIM

The International Club of Ascites (ICA) recently proposed a new definition of acute kidney injury (AKI) in cirrhotic patients. The study evaluated the ICA-AKI criteria and their association with the prognosis of cirrhotic patients with gastric variceal bleeding (GVB).

METHODS

A retrospective cohort study using prospective database of cirrhotic patients hospitalized with the first presentation of acute GVB at Taipei Veterans General Hospital from April 2007 to December 2010 was performed to evaluate the development of AKI. The study used Cox proportional hazards model to examine the association of ICA-AKI criteria and mortality.

RESULTS

Of 113 patients, 46 (41%) fulfilled the ICA-AKI criteria and most (70%) initially had stage 1 AKI. Child-Pugh score, systemic blood pressure at admission, and number of blood units transfused before endoscopy were independent predictors of AKI. Among patients with AKI, 30% progressed to higher stages with more advanced liver disease, lower serum sodium, more units of blood transfusion, higher frequency of infection, and higher serum creatinine levels at diagnosis of AKI. The 6-week mortality rate was significantly higher in patients with AKI than in patients without AKI (37% vs 3%, P < 0.001), and AKI stages were independent predictors of 3-month survival (93% in patients without AKI, 73% in stage 1, and 30% in stages 2 and 3, P = 0.005).

CONCLUSIONS

The occurrence of AKI as defined by the ICA criteria is common in cirrhotic patients with acute GVB. The presence of AKI was associated with much higher 6-week mortality, and the stages of AKI further predicted 3-month survival.

Critical care management of the patient with cirrhosis awaiting liver transplant in the intensive care unit

Patients with cirrhosis who are awaiting liver transplantation (LT) are at high risk for developing critical illnesses. Current liver allocation policies that dictate a "sickest first" approach coupled with a mismatch between need and availability of organs result in longer wait times, and thus, patients are becoming increasingly ill while awaiting organ transplantation. Even patients with well-compensated cirrhosis may suffer acute deterioration; the syndrome of acute-on-chronic liver failure (ACLF) results in multisystem organ dysfunction and a marked increase in associated short-term morbidity and mortality. For patients on transplant waiting lists, the development of multisystem organ failure may eliminate candidacy for transplant by virtue of being "too sick" to safely undergo transplantation surgery. The goals of intensive care management of patients suffering ACLF are to rapidly recognize and treat inciting events (eg, infection and bleeding) and to aggressively support failing organ systems to ensure that patients may successfully undergo LT. Management of the critically ill ACLF patient awaiting transplantation is best accomplished by multidisciplinary teams with expertise in critical care and transplant medicine. Such teams are well suited to address the needs of this unique patient population and to identify patients who may be too ill to proceed to transplantation surgery. The focus of this review is to identify the common complications of ACLF and to describe our approach management in critically ill patients awaiting LT in our centers. Liver Transplantation 23 1465-1476 2017 AASLD.

Significance of oliguria in critically ill patients with chronic liver disease

Clinical guidelines recommend using Kidney Disease Improving Global Outcomes (KDIGO) criteria for the diagnosis and classification of acute kidney injury (AKI) in patients with chronic liver disease (CLD). Concerns have been raised about the use of urine output (UO) criteria in CLD. We examined the significance of oliguria meeting the urine output criteria for AKI (AKI-UO) and examined its association with clinical outcomes in CLD patients. Using an 8-year clinical database from a large university medical center, 3458 patients with CLD were identified. AKI occurred in 2854 (82.5%) patients when they fulfilled any KDIGO criteria. When serum creatinine (SC) and UO criteria were used, 604 patients (17.5%) had no evidence of AKI and had the lowest hospital mortality rate (5%). Using AKI-UO criteria alone, 2103 patients (60.8%) were classified as stage 2-3 AKI. When only SC criteria were applied, 1281 (61%) of those patients with stage 2-3 AKI-UO were misclassified as either no AKI or AKI stage 1. Patients reclassified with AKI according to UO criteria (AKI-UO) had nearly a 3-fold increased rate of hospital mortality compared with patients without any AKI (14.6% versus 5%; P < 0.001) and more than a 50% increased mortality compared with stage 1 AKI-SC (14.6% versus 9%; P < 0.001). Patients with transient oliguria (AKI-UO stage 1) had increased mortality rates compared with patients without oliguria (14.9% versus 6.9%; P < 0.001).

CONCLUSION

CLD patients have a high incidence of AKI. Compared with creatinine criteria alone, incorporating UO into the diagnostic criteria increased the measured incidence of AKI. Stage 2-3 AKI-UO has a high negative impact on hospital mortality. (Hepatology 2017;66:1592-1600).

AKI persistence at 48 h predicts mortality in patients with acute on chronic liver failure

BACKGROUND AND AIM

Management of acute kidney injury (AKI) in cirrhotics has undergone a paradigm change. We evaluated the impact of AKI persistence at 48 h on outcome in patients with acute on chronic liver failure (ACLF).

METHODS

Consecutive patients with ACLF (n = 373) were prospectively followed. AKI was defined as increase in serum creatinine of 0.3 mg/dl or 1.5- to 2-fold from baseline. Persistent AKI was defined as nonresponsive AKI at 48 h with respect to admission serum creatinine.

RESULTS

AKI at admission was present in 177 (47.5 %) patients. At 48 h, 73 % patients had persistent AKI and 27 % had responsive AKI. High Model for End-Stage Liver Disease (MELD) (≥26) [p, odds ratio (OR), 95 % confidence interval (CI)] [<0.001, 3.65 (2.1-3.67)], systemic inflammatory response syndrome (SIRS) [0.03, 1.6 (1.02-21.6)], and age (≥42 years) [0.03, 1.84 (1.19-2.85)] were significant predictors of AKI persistence. Persistent AKI was associated with significantly higher in-hospital mortality [p < 0.001, hazard ratio (HR) 1.7, 95 % CI 1.32-2.27]. We further found a lower cutoff for serum creatinine of 1.14 mg/dl at 48 h with better sensitivity of 61 %, specificity of 61 %, and likelihood ratio (LR+) of 1.6, correctly classifying 61 %, as against the conventional cutoff of 1.5 mg/dl with sensitivity of 37 %, specificity of 57 %, and LR+ of 3.3, correctly classifying 56 %. This new cutoff also predicted mortality with higher odds (OR 2.4, 95 % CI 1.3-4.8) as compared with the conventional cutoff (OR 2.1, 95 % CI 1.1-4.1).

CONCLUSION

AKI persistence at 48 h predicts mortality better than serum creatinine of 1.5 mg/dl in patients with ACLF. Serum creatinine value of 1.14 mg/dl and smaller increases in its value should be considered for risk stratification of patients with ACLF for interventional strategies.

Development of predisposition, injury, response, organ failure model for predicting acute kidney injury in acute on chronic liver failure

BACKGROUND AND AIM

There is limited data on predictors of acute kidney injury in acute on chronic liver failure. We developed a PIRO model (Predisposition, Injury, Response, Organ failure) for predicting acute kidney injury in a multicentric cohort of acute on chronic liver failure patients.

PATIENTS AND METHODS

Data of 2360 patients from APASL-ACLF Research Consortium (AARC) was analysed. Multivariate logistic regression model (PIRO score) was developed from a derivation cohort (n=1363) which was validated in another prospective multicentric cohort of acute on chronic liver failure patients (n=997).

RESULTS

Factors significant for P component were serum creatinine[(≥2 mg/dL)OR 4.52, 95% CI (3.67-5.30)], bilirubin [(<12 mg/dL,OR 1) vs (12-30 mg/dL,OR 1.45, 95% 1.1-2.63) vs (≥30 mg/dL,OR 2.6, 95% CI 1.3-5.2)], serum potassium [(<3 mmol/LOR-1) vs (3-4.9 mmol/L,OR 2.7, 95% CI 1.05-1.97) vs (≥5 mmol/L,OR 4.34, 95% CI 1.67-11.3)] and blood urea (OR 3.73, 95% CI 2.5-5.5); for I component nephrotoxic medications (OR-9.86, 95% CI 3.2-30.8); for R component,Systemic Inflammatory Response Syndrome,(OR-2.14, 95% CI 1.4-3.3); for O component, Circulatory failure (OR-3.5, 95% CI 2.2-5.5). The PIRO score predicted acute kidney injury with C-index of 0.95 and 0.96 in the derivation and validation cohort. The increasing PIRO score was also associated with mortality (P<.001) in both the derivation and validation cohorts.

CONCLUSIONS

The PIRO model identifies and stratifies acute on chronic liver failure patients at risk of developing acute kidney injury. It reliably predicts mortality in these patients, underscoring the prognostic significance of acute kidney injury in patients with acute on chronic liver failure.

Biomarkers of Renal Injury in Cirrhosis: Association with Acute Kidney Injury and Recovery after Liver Transplantation

BACKGROUND

To define urine or serum biomarkers in predicting renal function recovery after liver transplantation (LT).

METHODS

Adults listed for LT (February 2011-July 2014) and with modified diet for renal disease-6 (MDRD-6) <60 mL/min provided urine/blood samples at baseline and serially until LT for biomarkers in serum (pg/mL) and urine (pg/mg creatinine).

RESULTS

Of 271 LT listed patients (mean age 57 years, 63% males, median listing MELD 17.5), 1 year acute kidney injury (AKI) probability was 49%, with odds of 1.3-, 3.0-, 4.6-, and 8.5-fold times for listing MELD 16-20, 21-25, 26-30, and >30, compared to MELD <16. Thirty-seven people died over 1 year from the time of listing, with twofold increased odds with AKI. Among 67 patients with MDRD <60, only urinary epidermal growth factor was different comparing AKI (increase in serum creatinine ≥0.3 mg/dL from baseline within past 3 months) vs. no AKI (2,254 vs. 4,253, p = 0.003). Differences between acute tubular necrosis (ATN) and hepatorenal syndrome could not be ascertained for a small sample of 3 patients with ATN. Analyzing 15 of 43 receiving LT and MDRD-6 <30 prior to LT, biomarkers were not different comparing 5 patients recovering renal function (MDRD-6 >50 mL/min) at 6 months vs. 10 without recovery.

CONCLUSIONS

AKI is common among LT listed patients, with a negative impact on transplant-free survival. Serum and urine biomarkers are not associated with the recovery of renal function after LT. Multicenter studies are suggested to (a) develop strategies to reduce the development of AKI and (b) derive novel biomarkers for use in accurately predicting renal recovery after LT.

Acute kidney injury in acute-on-chronic liver failure: where does hepatorenal syndrome fit?

Renal dysfunction occurs in 25% to 50% of patients with cirrhosis admitted to the hospital with an acute episode of hepatic decompensation and may be due to underlying chronic kidney disease, an acute deterioration, or both. An acute deterioration in renal function in cirrhotic patients is now collectively referred to as acute kidney injury (AKI), which has been subclassified into different grades of severity that identify prognostic groups. Acute-on-chronic liver failure is characterized by acute hepatic and/or extrahepatic organ failure driven by a dysregulated immune response and systemic inflammatory response. AKI is also one of the defining features of ACLF and a major component in grading the severity of acute-on-chronic liver failure. As such, the pattern of AKI now observed in patients admitted to the hospital with acutely decompensated liver disease is likely to be one of inflammatory kidney injury including acute tubular injury (referred in this review as non-hepatorenal syndrome [HRS]-AKI) rather than HRS. As the management and supportive treatment of non-HRS-AKI potentially differ from those of HRS, then from the nephrology perspective, it is important to distinguish between non-HRS-AKI and HRS-AKI when reviewing patients with acute-on-chronic liver failure and AKI, so that appropriate and early management can be instituted.

Urine Interleukin 18 and Lipocalin 2 Are Biomarkers of Acute Tubular Necrosis in Patients With Cirrhosis: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Acute kidney injury (AKI) is a common complication in patients with cirrhosis that increases mortality. The most common causes of AKI in these patients are prerenal azotemia, acute tubular necrosis (ATN), and hepatorenal syndrome; it is important to determine the etiology of AKI to select the proper treatment and predict patient outcome. Urine biomarkers could be used to differentiate between patients with ATN and functional causes of AKI. We performed a systematic review and meta-analysis of published studies to determine whether urine levels of interleukin (IL)18 and lipocalin 2 or neutrophil gelatinase-associated lipocalin (NGAL) are associated with the development of ATN in patients with cirrhosis.

METHODS

We searched MEDLINE, Scopus, ISI Web of Knowledge, and conference abstracts through December 31, 2015, for studies that assessed urine biomarkers for detection of acute kidney injury in patients with cirrhosis or reported an association between urine biomarkers and all-cause mortality in these patients. We included only biomarkers assessed in 3 or more independent studies, searching for terms that included urine biomarkers, cirrhosis, NGAL, and IL18. We calculated the pooled sensitivities and specificities for detection and calculated the area under the receiver operating characteristic curve (AUC) values using a bivariate logistic mixed-effects model. We used the χ² test to assess heterogeneity among studies.

RESULTS

We analyzed data from 8 prospective studies, comprising 1129 patients with cirrhosis. We found urine levels of the markers discriminated between patients with ATN and other types of kidney impairments, with AUC values of 0.88 for IL18 (95% confidence interval [CI], 0.79-0.97) and 0.89 for NGAL (95% CI, 0.84-0.94). Urine levels of IL18 identified patients who would die in the hospital or within 90 days (short-term mortality) with an AUC value of 0.76 (95% CI, 0.68-0.85); NGAL identified these patients with the same AUC (0.76; 95% CI, 0.71-0.82).

CONCLUSIONS

In a systematic review and meta-analysis, we found that urine levels of IL18 and NGAL from patients with cirrhosis discriminate between those with ATN and other types of kidney impairments, with AUC values of 0.88 and 0.89, respectively. Urine levels of IL18 and NGAL identified patients with short-term mortality with an AUC value of 0.76. These biomarkers might be used to determine prognosis and select treatments for patients with cirrhosis.

Acute Kidney Injury in Cirrhosis: Baseline Serum Creatinine Predicts Patient Outcomes

OBJECTIVES

The International Ascites Club (IAC) recently defined Stage 1 acute kidney injury (AKI) for cirrhosis as an acute increase in serum creatinine (SCr) by ≥0.3 mg/dl or by ≥50% in <48 h from a stable value within 3 months. The baseline SCr may influence AKI risk and patient outcomes. The objective of this study is to determine in cirrhosis whether the baseline SCr has any effect on the in-hospital AKI course and patient survival.

METHODS

North American Consortium for the Study of End-Stage Liver Disease is a consortium of tertiary-care hepatology centers prospectively enroling non-elective cirrhotic inpatients. Patients with different baseline SCr levels (≤0.5, 0.51-1.0, 1.01-1.5, >1.5 mg/dl) were evaluated for the development of AKI, and compared for AKI outcomes and 30-day survival.

RESULTS

653 hospitalized cirrhotics (56.7±10years, 64% men, 30% with infection) were included. The incidence of AKI was 47% of enrolled patients. Patients with higher baseline SCr were more likely to develop AKI, with significantly higher delta and peak SCr (P<0.001) than the other groups, more likely to have a progressive AKI course (P<0.0001), associated with a significantly reduced 30-day survival (P<0.0001). Multivariate logistic regression showed that the delta SCr during an AKI episode to be the strongest factor impacting AKI outcomes and survival (P<0.001), with a delta SCr of 0.70 mg/dl having a 68% sensitivity and 80% specificity for predicting 30-day mortality.

CONCLUSIONS

Admitted cirrhotic patients with higher baseline SCr are at higher risk for in-hospital development of AKI, and more likely to have AKI progression with reduced survival. Therefore, such patients should be closely monitored and treated promptly for their AKI.

Kidney Injury in Liver Disease

Acute kidney injury (AKI) occurs frequently in patients with liver disease and increases morbidity and mortality. Hepatorenal syndrome is a common cause of AKI in patients with decompensated cirrhosis and is due to alterations in systemic and renal hemodynamics. Serum creatinine-based estimation of kidney function is a key component of the Model for End-stage Liver Disease score in liver transplant candidates. Continuous renal replacement therapy is used in critically ill patients with liver failure and AKI. Simultaneous liver-kidney transplantation (SLK) may be required in patients with liver failure and prolonged AKI. Identification of appropriate candidates for SLK remains controversial.

A Dynamic Definition of Acute Kidney Injury Does not Improve Prognosis Assessment in Acutely Decompensated Patients with Cirrhosis

BACKGROUND/OBJECTIVES

to compare the prognostic accuracy for 28 and 90-day transplant-free mortality of a modified CLIF-SOFA score (including a dynamic definition of acute kidney injury) with that of the classic CLIF-SOFA score and KDIGO score for acute kidney injury in patients with acute decompensation of cirrhosis.

METHODS

A retrospective analysis of all admissions of acutely decompensated patients with cirrhosis was carried out from January 2012 to December 2014. Classic and modified CLIF-SOFA scores were analyzed, as well as acute kidney injury diagnosis using the KDIGO score regarding their accuracy for 28- and 90-day transplant free mortality prediction.

RESULTS

108 admissions were analyzed. Acute kidney injury diagnosis was met in 37 (34%) patients. Acute-on-chronic liver failure was diagnosed in 59 (55%) patients using the classic CLIF-SOFA score; and in 64 (59%) patients using the modified CLIF-SOFA score. Both CLIF-SOFA scores were highly effective in predicting 28-day transplant-free mortality (AUCROC 0.93 and 0.92, p = 0.34) as well as 90-day transplant-free mortality (AUCROC 0.79 and 0.78, p = 0.78). Acute kidney injury diagnosis had significantly lower accuracy in mortality assessment (28 and 90-day transplant free mortality AUCROC 0.67 [p = 0.002] and 0.63 [p = 0.02]).

CONCLUSIONS

To our knowledge, this is the first evidence of the limited impact of modifying the fixed kidney injury definition currently used for acute-on-chronic liver failure.

Evaluation of Absolute Serum Creatinine Changes in Staging of Cirrhosis-Induced Acute Renal Injury and its Association with Long-term Outcomes

BACKGROUND/AIMS

To assess the prognostic accuracy of absolute serum creatinine (sCr) changes ('Delta-sCr') on the long-term outcomes in cirrhotic patients, and evaluate the performance of the 'Delta-sCr' approach to stage acute kidney injury (AKI), compared with the Kidney Disease Improving Global Outcomes (KDIGO) criteria.

METHODS

We conducted a retrospective analysis of 333 hospitalized patients. We classified AKI stages using two methods: 1) KDIGO AKI criteria; 2) 'Delta-sCr' system, defined by the difference between the baseline and the peak sCr value during the hospitalization. The end point was the hazard of 1-year death.

RESULTS

The prevalence of AKI in cirrhotic patients was 18.01% by the KDIGO criteria, and 25.22% by the 'Delta-sCr' system. On multivariable Cox hazard analysis, both of the two methods were independent predictive factors of death ('Delta-sCr' system: OR=2.911, p<0.001), (KDIGO criteria: OR=2.065, p<0.001). However, the 'Delta-sCr' system provided a modest improvement in classification over the KDIGO criteria with a net reclassification improvement (NRI) of 28.7% (p<0.001) and integrated discrimination improvement (IDI) of 7.5% (p=0.03). And the predictive value of the 'Delta-sCr' system could be significantly improved (p=0.006), when combined with age and MELD score.

CONCLUSION

The Delta-sCr is associated with the 1-year mortality. And the 'Delta-sCr' system may optimize the discrimination of risk prediction.

Bile Cast Nephropathy in Cirrhotic Patients: Effects of Chronic Hyperbilirubinemia

OBJECTIVES

The aim of this study was to determine the prevalence of bile cast nephropathy (BCN) in autopsied cirrhotic patients and to correlate BCN with clinical and laboratory data to direct attention to this underrecognized renal complication of liver failure.

METHODS

We assessed 114 autopsy cases of cirrhosis for the presence of renal intratubular bile casts using Hall stain for bile. Presence of bile casts was correlated with etiology of cirrhosis, clinical and laboratory data, and histologic findings.

RESULTS

Bile casts were identified in 55% of cases. The most common etiology of cirrhosis was hepatitis C virus (HCV) infection (52%), and serum creatinine ( P  = .02) and serum urea nitrogen ( P  = .01) were significantly higher in the Hall-positive group. Conjugated bilirubin was below 20 mg/dL in 90%, and levels below 10 mg/dL were noted in 80% of cases.

CONCLUSIONS

To our knowledge, this is the largest study of BCN in human subjects and a first report describing the association of BCN with HCV-related cirrhosis. We demonstrated that in the face of protracted chronic hyperbilirubinemia, bile casts are formed at much lower bilirubin levels than previously thought. Furthermore, we proposed an algorithm to assist in better identification of bile casts.