Overview
Detect acute kidney injury early in cirrhosis, reverse common causes, diagnose HRS-AKI carefully, and use vasoconstrictor therapy without causing respiratory or ischaemic harm.
AKI in cirrhosis is defined by change from baseline rather than a single high threshold. Creatinine may be low at baseline because of sarcopenia, so a rise of at least 26 micromol/L within 48 hours or at least 50% within seven days is clinically important under standard AKI criteria. Confirm the trend, inspect urine output and retrieve recent results. Do not wait for creatinine to reach a conventional 'renal failure' range before acting.
Initial reasoning separates reduced renal perfusion, intrinsic injury and obstruction. Bleeding, diarrhoea, vomiting and excess diuresis suggest volume loss; infection and SBP can cause vasodilatation and tubular injury; aminoglycosides, NSAIDs, contrast and some other medicines add renal stress. Proteinuria, haematuria, casts or an atypical history suggests intrinsic disease. Renal ultrasound addresses obstruction but does not diagnose HRS.