Acute kidney injury network criteria as a predictor of hospital mortality in cirrhotic patients with ascites

Acute kidney injury and acute-on-chronic liver failure classifications in prognosis assessment of patients with acute decompensation of cirrhosis

OBJECTIVE

Prognostic stratification of patients with cirrhosis is common clinical practice. This study compares the prognostic accuracy (28-day and 90-day transplant-free mortality) of the acute-on-chronic liver failure (ACLF) classification (no ACLF, ACLF grades 1, 2 and 3) with that of acute kidney injury (AKI) classification (no AKI, AKI stages 1, 2 and 3).

DESIGN

The study was performed in 510 patients with an acute decompensation of cirrhosis previously included in the European Association for the Study of the Liver-Chronic Liver Failure consortium CANONIC study. ACLF was evaluated at enrollment and 48 h after enrollment, and AKI was evaluated at 48 h according to Acute Kidney Injury Network criteria.

RESULTS

240 patients (47.1%) met the criteria of ACLF at enrollment, while 98 patients (19.2%) developed AKI. The presence of ACLF and AKI was strongly associated with mortality. 28-day transplant-free mortality and 90-day transplant-free mortality of patients with ACLF (32% and 49.8%, respectively) were significantly higher with respect to those of patients without ACLF (6.2% and 16.4%, respectively; both p<0.001). Corresponding values in patients with and without AKI were 46% and 59%, and 12% and 25.6%, respectively (p<0.0001 for both). ACLF classification was more accurate than AKI classification in predicting 90-day mortality (area under the receiving operating characteristic curve=0.72 vs 0.62; p<0.0001) in the whole series of patients. Moreover, assessment of ACLF classification at 48 h had significantly better prognostic accuracy compared with that of both AKI classification and ACLF classification at enrollment.

CONCLUSIONS

ACLF stratification is more accurate than AKI stratification in the prediction of short-term mortality in patients with acute decompensation of cirrhosis.

Patients with cirrhosis in the ED: early predictors of infection and mortality

BACKGROUND

Patients with cirrhosis have high risk of bacterial infections and cirrhosis decompensation, resulting in admission to emergency department (ED). However, there are no criteria developed in the ED to identify patients with cirrhosis with bacterial infection and with high mortality risk.

STUDY OBJECTIVE

The objective of the study is to identify variables from ED arrival associated with bacterial infections and inhospital mortality.

METHODS

This is a retrospective single-center study using a tertiary hospital's database to identify consecutive ED patients with decompensated cirrhosis. Clinical variables and laboratory results were obtained by chart review. Logistic regression models were built to determine variables independently associated with bacterial infection and mortality. Scores using these variables were designed.

RESULTS

One hundred forty-nine patients were enrolled, most of them males (77.9%) with alcoholic cirrhosis (53%) and advanced liver disease (Child-Pugh C, 47.2%). Bacterial infections were diagnosed in 72 patients (48.3%), and 36 (24.2%) died during hospital stay. Variables independently associated with bacterial infection were lymphocytes less than or equal to 900/mm(3) (odds ratio [OR], 3.85 [95% confidence interval {CI}, 1.47-10]; P = .006) and C-reactive protein greater than 59.4 mg/L (OR, 5.05 [95% CI, 1.93-13.2]; P = .001). Variables independently associated with mortality were creatinine greater than 1.5 mg/dL (OR, 4.35 [95% CI, 1.87-10.1]; P = .001) and international normalized ratio greater than 1.65 (OR, 3.71 [95% CI, 1.6-8.61]; P = .002). Scores designed to predict bacterial infection and mortality (Mortality in Cirrhosis Emergency Department Score) had an area under the receiver operating characteristic curve of 0.82 and 0.801, respectively. The Mortality in Cirrhosis Emergency Department Score performed better than Model for End-Stage Liver Disease score.

CONCLUSIONS

In this cohort of ED patients with decompensated cirrhosis, lymphopenia and elevated C-reactive protein were related to bacterial infections, and elevated creatinine and international normalized ratio were related to mortality. Scores built with these variables should be prospectively validated.

Definition and Diagnosis of Acute Kidney Injury in Cirrhosis

BACKGROUND

Acute kidney injury (AKI) is a common complication of advanced cirrhosis. Type 1 hepatorenal syndrome is the best-known and most severe form of AKI, and it has a precise definition and a set of specific diagnostic criteria. More recently, it has become recognized that milder degrees of renal dysfunction also have a negative impact on patient outcome in various patient populations. Key Messages: Several definitions and criteria for staging the severity of AKI have been proposed, including the RIFLE (Risk, Injury, Failure, Loss of Function and End-Stage Renal Disease) group, the Acute Kidney Injury Network (AKIN), and the Kidney Disease: Improving Global Outcome (KDIGO) group. All of them incorporate some changes of serum creatinine and urine output in the definition and staging of AKI. The hepatology community has mostly embraced the AKIN diagnostic and staging criteria and has applied them in the prognostication of patients with advanced cirrhosis. However, the AKIN criteria have not been strictly applied in all studies on cirrhosis. This is partly related to the fact that changes in urine output are difficult to assess in advanced cirrhosis, and partly related to the difficulty in defining the baseline serum creatinine from which the change in serum creatinine is calculated. This has led to some confusion in the interpretation of results of the various studies on AKI in cirrhosis. More recently, some investigators have suggested incorporating the AKIN criteria with setting a lower limit of serum creatinine of 1.5 mg/dl in determining the diagnosis and prognosis of AKI in cirrhosis.

CONCLUSIONS

This is an ongoing debate as to how best to define AKI in cirrhosis. In the near future there should be prospective clinical trials that will clarify which diagnostic and staging criteria of AKI will best serve the cirrhotic population.

The Treatment of Hepatorenal Syndrome

Hepatorenal syndrome (HRS) is a severe complication that often occurs in patients with cirrhosis and ascites. HRS is a functional renal failure that develops mainly as a consequence of a severe cardiovascular dysfunction which is characterized by an extreme splanchnic arterial vasodilation and a reduction of cardiac output. HRS may develop in two clinical types: as an acute and rapidly progressive renal failure (AKI-HRS) or as chronic and not progressive renal failure (CKD-HRS). Several small studies and some randomized control studies have been published on the use of terlipressin plus albumin in the treatment of HRS, mainly on AKI-HRS. Terlipressin plus albumin was shown to improve renal function in almost 35-45% of patients with AKI-HRS, as well as to improve short-term survival in these patients. Terlipressin was most commonly used by intravenous boluses moving from an initial dose of 0.5-1 mg every 4 h to 3 mg every 4 h in the case of a nonresponse. In other studies, terlipressin was also given by continuous intravenous infusion. Thus, the best way to administer terlipressin in the treatment of HRS has not yet been defined. α-Adrenergic drugs, such as intravenous norepinephrine or oral midodrine plus subcutaneous octreotide, administered with albumin have also been used in the treatment of AKI-HRS, with promising results. However, we need further studies in order to define whether they can represent a real therapeutic alternative. In conclusion, available data are sufficient to state that the use of terlipressin plus albumin has really changed the management of HRS. Nevertheless, some crucial unsolved issues still exist, in particular: (a) how to predict nonresponse to treatment, (b) how to manage nonresponse to treatment and (c) how to consider the response in those patients who are candidates for liver transplant in the priority allocation process.

Acute kidney injury and hepatorenal syndrome in cirrhosis

Cirrhosis is the eighth leading cause of "years of lost life" in the United States and accounts for approximately 1% to 2% of all deaths in Europe. Patients with cirrhosis have a high risk of developing acute kidney injury. The clinical characteristics of hepatorenal syndrome (HRS) are similar to prerenal uremia, but the condition does not respond to volume expansion. HRS type 1 is rapidly progressive whereas HRS type 2 has a slower course often associated with refractory ascites. A number of factors can precipitate HRS such as infections, alcoholic hepatitis, and bleeding. The monitoring, prevention, early detection, and treatment of HRS are essential. This paper reviews the value of early evaluation of renal function based on two new sets of diagnostic criteria. Interventions for HRS type 1 include terlipressin combined with albumin. In HRS type 2, transjugular intrahepatic portosystemic shunt (TIPS) should be considered. For both types of HRS patients should be evaluated for liver transplantation.

Renal impairment in cirrhosis unrelated to hepatorenal syndrome

Renal impairment is common in liver disease and may occur as a consequence of the pathophysiological changes that underpin cirrhosis or secondary to a pre-existing unrelated insult. Nevertheless, the onset of renal impairment often portends a worsening prognosis. Hepatorenal syndrome remains one of the most recognized and reported causes of renal impairment in cirrhosis. However, other causes of renal impairment occur and can be classified into prerenal, intrinsic or postrenal, which are the subjects of the present review.

Renal replacement therapy in the ICU: comparison of clinical features and outcomes of patients with acute kidney injury and dialysis-dependent end-stage renal disease

BACKGROUND

The goal of this study is to study clinical features and outcomes of the patients who had renal replacement therapy (RRT) in the intensive care unit (ICU) between 2000 and 2007.

METHODS

We retrospectively studied 222 patients.

RESULTS

Overall ICU mortality and invasive mechanical ventilation (IMV) rates were 58.1 and 61.3 %. The mean APACHE II score was 27.6 ± 8.3. Chronic dialysis (CD) patients formed 45.5 % of the study population. Acute kidney injury (AKI) patients had higher rates of IMV (73 vs. 51.5 %, p = 0.002), cancer (27.8 vs. 7.9 %, p ≤ 0.001) and mortality (67.8 vs. 50.5 %, p = 0.010) than CD patients. AKI patients with normal kidney function (NKF) before ICU admission had poorer prognosis than acute-on-chronic kidney disease (CKD) and CD patients (78.6, 51 and 50.5 %, respectively, p ≤ 0.001). Multivariate analysis showed that IMV (OR, 14.8; 95 % CI, 5.47-40.05; p ≤ 0.001) and having NKF before hospitalization (OR, 2.8; 95 % CI, 1.04-7.37; p = 0.041) were predictors of overall ICU mortality. Additionally, IMV is found as a prognostic factor for both AKI (OR, 18.7; 95 % CI, 4.48-77.72; p ≤ 0.001) and CD patients (OR, 8.14; 95 % CI, 2.01-33.04; p = 0.003), but APACHE II score is meaningful only for CD patients (OR, 1.13; 95 % CI, 1.02-1.26; p = 0.024). The areas under the ROC curves for APACHE II score were 0.52 (95 % CI, 0.39-0.66) for AKI and 0.78 (95 % CI, 0.55-0.89) for CD patients.

CONCLUSION

The observed ICU mortality among patients requiring RRT is high and IMV is associated with mortality. AKI patients have increased mortality compared to CD patients. AKI patients with past NKF have poorer prognosis than acute-on-CKD and CD patients.

Urinary biomarkers and progression of AKI in patients with cirrhosis

BACKGROUND AND OBJECTIVES

AKI is a common and severe complication in patients with cirrhosis. AKI progression was previously shown to correlate with in-hospital mortality. Therefore, accurately predicting which patients are at highest risk for AKI progression may allow more rapid and targeted treatment. Urinary biomarkers of structural kidney injury associate with AKI progression and mortality in multiple settings of AKI but their prognostic performance in patients with liver cirrhosis is not well known.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A multicenter, prospective cohort study was conducted at four tertiary care United States medical centers between 2009 and 2011. The study comprised patients with cirrhosis and AKI defined by the AKI Network criteria evaluating structural (neutrophil gelatinase-associated lipocalin, IL-18, kidney injury molecule-1 [KIM-1], liver-type fatty acid-binding protein [L-FABP], and albuminuria) and functional (fractional excretion of sodium [FENa]) urinary biomarkers as predictors of AKI progression and in-hospital mortality.

RESULTS

Of 188 patients in the study, 44 (23%) experienced AKI progression alone and 39 (21%) suffered both progression and death during their hospitalization. Neutrophil gelatinase-associated lipocalin, IL-18, KIM-1, L-FABP, and albuminuria were significantly higher in patients with AKI progression and death. These biomarkers were independently associated with this outcome after adjusting for key clinical variables including model of end stage liver disease score, IL-18 (relative risk [RR], 4.09; 95% confidence interval [95% CI], 1.56 to 10.70), KIM-1 (RR, 3.13; 95% CI, 1.20 to 8.17), L-FABP (RR, 3.43; 95% CI, 1.54 to 7.64), and albuminuria (RR, 2.07; 95% CI, 1.05-4.10) per log change. No biomarkers were independently associated with progression without mortality. FENa demonstrated no association with worsening of AKI. When added to a robust clinical model, only IL-18 independently improved risk stratification on a net reclassification index.

CONCLUSIONS

Multiple structural biomarkers of kidney injury, but not FENa, are independently associated with progression of AKI and mortality in patients with cirrhosis. Injury marker levels were similar between those without progression and those with progression alone.

Renal dysfunction in patients with cirrhosis: Where do we stand?

Patients with cirrhosis and renal failure are high-risk patients who can hardly be grouped to form precise instructions for diagnosis and treatment. When it comes to evaluate renal function in patients with cirrhosis, determination of acute kidney injury (AKI), chronic kidney disease (CKD) or AKI on CKD should be made. First it should be excluded the prerenal causes of AKI. All cirrhotic patients should undergo renal ultrasound for measurement of renal resistive index in every stage of liver dysfunction and urine microscopy for differentiation of all causes of AKI. If there is history of dehydration on the ground of normal renal ultrasound and urine microscopy the diuretics should be withdrawn and plasma volume expansion should be tried with albumin. If the patient does not respond, the correct diagnosis is HRS. In case there is recent use of nephrotoxic agents or contrast media and examination shows shock, granular cast in urinary sediment and proteinuria above 0.5 g daily, acute tubular necrosis is the prominent diagnosis. Renal biopsy should be performed when glomerular filtration rate is between 30-60 mL/min and there are signs of parenchymal renal disease. The acute renal function is preferable to be assessed with modified AKIN. Patients with AKIN stage 1 and serum creatinine ≥ 1.5 mg/dL should be at close surveillance. Management options include hemodynamic monitoring and management of fluid balance and infections, potentially driving to HRS. Terlipressin is the treatment of choice in case of established HRS, administered until there are signs of improvement, but not more than two weeks. Midodrine is the alternative for therapy continuation or when terlipressin is unavailable. Norepinephrine has shown similar effect with terlipressin in patients being in Intensive Care Unit, but with much lower cost than that of terlipressin. If the patient meets the requirements for transplantation, dialysis and transjugular intrahepatic portosystemic shunt are the bridging therapies to keep the transplant candidate in the best clinical status. The present review clarifies the latest therapeutic modalities and the proposed recommendations and algorithms in order to be applied in clinical practice.

Acute kidney injury in patients with cirrhosis: perils and promise

A 62-year-old man with cirrhosis secondary to hepatitis C and chronic alcohol abuse was admitted to the intensive care unit with hematemesis and mental status changes. Physical examination showed ascites and stigmata of chronic liver disease. Blood pressure was noted as 87/42 mm Hg and laboratory studies showed a serum creatinine level of 0.8 mg/dL, an estimated glomerular filtration rate of 84 mL/min/1.73 m(2) calculated using the Modification of Diet in Renal Disease Study equation, a serum sodium level of 123 mEq/L, a total serum bilirubin level of 4.3 mg/dL, and an international normalization ratio of 1.6. The patient was resuscitated with packed red blood cells and fresh-frozen plasma and bleeding was controlled. However, on the third day of admission, creatinine level increased to 1.5 mg/dL. Examination of urine sediment showed 1 to 5 bilirubin-stained granular casts per high-powered field and a few renal tubular epithelial cells. The urine sodium level was 21 mEq/L and the fractional excretion of sodium was 0.43%.

New consensus definition of acute kidney injury accurately predicts 30-day mortality in patients with cirrhosis and infection

BACKGROUND & AIMS

Participants at a consensus conference proposed defining cirrhosis-associated acute kidney injury (AKI) based on a >50% increase in serum creatinine level from the stable baseline value in <6 months or an increase of ≥ 0.3 mg/dL in <48 hours. We performed a prospective study to evaluate the ability of these criteria to predict mortality within 30 days of hospitalization among patients with cirrhosis and infection.

METHODS

We followed up 337 patients with cirrhosis who were admitted to the hospital with an infection or developed an infection during hospitalization (56% men; 56 ± 10 years of age; Model for End-Stage Liver Disease [MELD] score, 20 ± 8) at 12 centers in North America. We compared data on 30-day mortality, length of stay in the hospital, and organ failure between patients with and without AKI.

RESULTS

In total, based on the consensus criteria, 166 patients (49%) developed AKI during hospitalization. Patients who developed AKI were admitted with higher Child-Pugh scores than those who did not develop AKI (11.0 ± 2.1 vs 9.6 ± 2.1; P < .0001) as well as higher MELD scores (23 ± 8 vs 17 ± 7; P < .0001) and lower mean arterial pressure (81 ± 16 vs 85 ± 15 mm Hg; P < .01). Higher percentages of patients with AKI died within 30 days of hospitalization (34% vs 7%), were transferred to the intensive care unit (46% vs 20%), required ventilation (27% vs 6%), or went into shock (31% vs 8%); patients with AKI also had longer stays in the hospital (17.8 ± 19.8 vs 13.3 ± 31.8 days) (all P < .001). Of the AKI episodes, 56% were transient, 28% were persistent, and 16% resulted in dialysis. Mortality was higher among those without renal recovery (80%) compared with partial (40%) or complete recovery (15%) or those who did not develop AKI (7%; P < .0001).

CONCLUSIONS

Among patients with cirrhosis, 30-day mortality is 10-fold higher among those with irreversible AKI than those without AKI. The consensus definition of AKI accurately predicts 30-day mortality, length of hospital stay, and organ failure.

Current concepts in the diagnosis and classification of renal dysfunction in cirrhosis

BACKGROUND

Renal dysfunction is one of the most common complications of cirrhosis with high morbidity and mortality.

SUMMARY

In subjects with cirrhosis, renal dysfunction can present either as a direct consequence of cirrhosis (e.g. hepatorenal syndrome type I and type II) or secondary to etiologies other than cirrhosis (chronic kidney disease due to diabetic nephropathy, prerenal azotemia), or patients with cirrhosis may have renal dysfunction resulting directly from cirrhosis and an underlying chronic kidney disease.

KEY MESSAGES

Given the challenges in the differential diagnosis of renal dysfunction and insufficient accuracy of serum creatinine and creatinine-based glomerular filtration rate estimating equations in cirrhosis, there is an urgent need for more accurate biomarkers of renal dysfunction in this population. This review will discuss novel concepts for the diagnosis and classification of renal dysfunction in cirrhosis to overcome at least some of the diagnostic and therapeutic challenges. Additionally, a new classification will be proposed for renal dysfunction in cirrhosis.

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

BACKGROUND & AIMS

For several years hepatologists have defined acute renal failure in patients with cirrhosis as an increase in serum creatinine (sCr) ≥ 50% to a final value of sCr>1.5mg/dl (conventional criterion). Recently, the Acute Kidney Injury Network (AKIN) defined acute renal failure as acute kidney injury (AKI) on the basis of an absolute increase in sCr of 0.3mg/dl or a percentage increase in sCr ≥ 50% providing also a staging from 1 to 3. AKIN stage 1 was defined as an increase in sCr ≥ 0.3mg/dl or increase in sCr ≥ 1.5-fold to 2-fold from baseline. AKI diagnosed with the two different criteria was evaluated for the prediction of in-hospital mortality.

METHODS

Consecutive hospitalized patients with cirrhosis and ascites were included in the study and evaluated for the development of AKI.

RESULTS

Conventional criterion was found to be more accurate than AKIN criteria in improving the prediction of in-hospital mortality in a model including age and Child-Turcotte-Pugh score. The addition of either progression of AKIN stage or a threshold value for sCr of 1.5mg/dl further improves the value of AKIN criteria in this model. More in detail, patients with AKIN stage 1 and sCr<1.5mg/dl had a lower mortality rate (p=0.03), a lower progression rate (p=0.01), and a higher improvement rate (p=0.025) than patients with AKIN stage 1 and sCr ≥ 1.5mg/dl.

CONCLUSIONS

Conventional criterion is more accurate than AKIN criteria in the prediction of in-hospital mortality in patients with cirrhosis and ascites. The addition of either the progression of AKIN stage or the cut-off of sCr ≥ 1.5mg/dl to the AKIN criteria improves their prognostic accuracy.

Acute kidney injury is independently associated with death in patients with cirrhosis

BACKGROUND AND AIMS

Current creatine-based criteria for defining acute kidney injury (AKI) are validated in general hospitalised patients but their application to cirrhotics (who are younger and have reduced muscle mass) is less certain. We aimed to evaluate current definitions of AKI (acute kidney injury network (AKIN) criteria) in a population of cirrhotic patients and correlate this with outcomes.

METHODS

We prospectively identified patients with AKI and clinical, radiological or histological evidence of cirrhosis. We compared them with a control group with evidence of cirrhosis and no AKI.

RESULTS

162 cirrhotic patients were studied with a mean age of 56.8±14 years. They were predominantly male (65.4%) with alcoholic liver disease (78.4%). 110 patients had AKI: 44 stage 1, 32 stage 2 and 34 stage 3. They were well matched in age, sex and liver disease severity with 52 cirrhotics without AKI. AKI was associated with increased mortality (31.8% vs 3.8%, p<0.001). Mortality increased with each AKI stage; 3.8% in cirrhotics without AKI, 13.5% stage 1, 37.8% stage 2 and 43.2% stage 3 (p<0.001 for trend). Worsening liver disease (Child-Pugh class) correlated with increased mortality: 3.1% class A, 23.6% class B and 32.8% class C (p=0.006 for trend). AKI was associated with increased length of stay: median 6.0 days (IQR 4.0-8.75) versus 16.0 days (IQR 6.0-27.5), p<0.001. Multivariate analysis identified AKI and Child-Pugh classes B and C as independent factors associated with mortality.

CONCLUSIONS

The utility of AKIN criteria is maintained in cirrhotic patients. Decompensated liver disease and AKI appear to be independent variables predicting death in cirrhotics.

Association of AKI with mortality and complications in hospitalized patients with cirrhosis

Acute kidney injury (AKI) is a common and devastating complication in patients with cirrhosis. However, the definitions of AKI employed in studies involving patients with cirrhosis have not been standardized, lack sensitivity, and are often limited to narrow clinical settings. We conducted a multicenter, prospective observational cohort study of patients with cirrhosis and AKI, drawn from multiple hospital wards, utilizing the modern acute kidney injury network (AKIN) definition and assessed the association between AKI severity and progression with in-hospital mortality. Of the 192 patients who were enrolled and included in the study, 85 (44%) progressed to a higher AKIN stage after initially fulfilling AKI criteria. Patients achieved a peak severity of AKIN stage 1, 26%, stage 2, 24%, and stage 3, 49%. The incidence of mortality, general medical events (bacteremia, pneumonia, urinary tract infection), and cirrhosis-specific complications (ascites, encephalopathy, spontaneous bacterial peritonitis) increased with severity of AKI. Progression was significantly more common and peak AKI stage higher in nonsurvivors than survivors (P < 0.0001). After adjusting for baseline renal function, demographics, and critical hospital- and cirrhosis-associated variables, progression of AKI was independently associated with mortality (adjusted odds ratio = 3.8, 95% confidence interval 1.3-11.1).

CONCLUSION

AKI, as defined by AKIN criteria, in patients with cirrhosis is frequently progressive and severe and is independently associated with mortality in a stage-dependent fashion. Methods for earlier diagnosis of AKI and its progression may result in improved outcomes by facilitating targeted and timely treatment of AKI.