Working Party proposal for a revised classification system of renal dysfunction in patients with cirrhosis.

OBJECTIVES: To propose an improvement on the current classification of renal dysfunction in cirrhosis. Clinicians caring for patients with cirrhosis recognize that the development of renal dysfunction is associated with significant morbidity and mortality. While most cases of renal dysfunction in cirrhosis are functional in nature, developed as a result of changes in haemodynamics, cardiac function, and renal auto-regulation, there is an increasing number of patients with cirrhosis and structural changes in their kidney as a cause of renal dysfunction. Therefore, there is a need for a newer classification to include both functional and structural renal diseases. DESIGN: A working party consisting of specialists from multiple disciplines conducted literature search and developed summary statements, incorporating the renal dysfunction classification used in nephrology. These were discussed and revised to produce this proposal. SETTING: Multi-disciplinary international meeting. PATIENTS: None. INTERVENTIONS: Literature search using keywords of cirrhosis, renal dysfunction, acute kidney injury (AKI), chronic kidney injury (CKD), and hepatorenal syndrome. RESULTS: Acute kidney injury will include all causes of acute deterioration of renal function as indicated by an increase in serum creatinine of >50% from baseline, or a rise in serum creatinine of ≥ 26.4 µmol/L (≥ 0.3 mg/dL) in < 48 hours. Chronic renal disease will be defined as an estimated glomerular filtration rate (GFR) of < 60 ml/min calculated using the Modification of Diet in Renal Disease 6 (MDRD6) formula, recognising that the MDRD6 formula is not perfect for the cirrhotic patients and this may change as improved means of estimating GFR becomes available. Acute on chronic kidney disease will be defined as AKI superimposed on existing chronic renal disease using the above definitions for AKI and CKD. CONCLUSIONS: Accepting this new classification will allow studies into the epidemiology, incidence, prevalence, natural history and the development of new treatments for these subtypes of renal dysfunction in cirrhosis.