Today during Morning Teaching Conference at Hillcrest, one of our wonderful R1’s, Priyesha Bijlani, presented a “hot case” of a 74 year-old man with NASH cirrhosis and HFrEF who was admitted after he was found to have an AKI after a routine outpatient large-volume paracentesis. We discussed the diagnostic difficulties in this particular case, the differential for AKI (pre-renal due to poor PO intake, Hepatorenal Syndrome, and cardiorenal syndrome) as well as the diagnostic criteria and management of suspected hepatorenal syndrome. Ultimately, the patient’s AKI improved after albumin bolus and diuretic holiday, suggesting more likely a prerenal cause.
Key Learning Points:
1.) AKI in cirrhosis is usually due to volume depletion from prerenal causes (45%), ATN from hypotension or nephrotoxins (32%), or other (23%), which includes Hepatorenal Syndrome or abdominal compartment syndrome.
2.) Hepatorenal syndrome (HRS) is a process driven by portal hypertension, splanchnic vasodilation, decreased peripheral vascular resistance, all of which drive sympathetic activation and RAAS system activation, decreasing blood flow to the kidneys. It can be precipitated by bacterial infectious, GI bleeding, SBP, as well as acute fulminant hepatic failure. Type 1 HRS occurs more rapidly (doubling of Cr to >2.5 within 2 weeks) and can lead to end-stage kidney disease. Type 2 HRS occurs less rapidly.
3.) HRS is a diagnosis of exclusion. Because of this, other potential causes of AKI must be effectively ruled-out. Suggested diagnostic criteria include:
- No response after 48h of withholding diuretic therapy and albumin 1g/kg/day.
- No use of nephrotoxic medications
- No evidence of structural renal disease: Proteinuria < 500 mg/day, no microhematuria, and no renal ultrasound findings suggestive of obstructive disease.
4.) The treatment for HRS is designed to maximize renal perfusion by elevating mean arterial pressure, increase splanchnic vasoconstriction. Midodrine/Octreotide/Albumin is an option for patients on the wards, and norepinephrine/Albumin is an option for patients in the ICU. Unfortunately, patients who progress to end-stage renal disease are only candidates for renal replacement therapy as a bridge to liver or liver/kidney transplantation.