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General Reference ⬇

Nejm 1993;329:1862

Pathophys and Cause ⬆ ⬇

Cause:Multiple etiologies result in end-stage hepatic failure, which has 4 major complications: ascites, hemorrhage, renal failure, and encephalopathy

Pathophys:Nitrogen-induced types, by blood in gut or protein-containing food ingestion. Lactulose helps by producing H+ in bowel, which traps NH3, and by causing diarrhea.

Epidemiology ⬆ ⬇

Precipitated by infection, renal failure, diuretics, drugs, GI bleed, constipation, dietary protein.

Signs and Symptoms ⬆ ⬇

Sx:Organic brain syndrome/delirium (Delirium (Organic Brain Syndrome))

Si:Spectrum from mild flap (asterixis) to decorticate/decerebrate coma (Nejm 1968;278:876)

Course ⬆ ⬇

33% of pts w hepatic failure die from coma

Lab and Xray ⬆ ⬇

Lab: Chem:Blood NH3 elevated, although degree of elevation does not correlate with severity but may be useful to follow individual patient

Treatment ⬆

Rx:

(Nejm 1997;337:473)

1st: Lactulose 30-60 gm qd po to produce 2-4 acidic (pH <6) stools qd helps all types, though expensive (ADP J Club 2004;141:59); can cause osmotic diarrhea and hypernatremia

2nd: Nonabsorbable antibiotics like:

  • Rifaximin 400 mg tid; superior to other abx, (Nejm 2010;362:1071, 1140)
  • Neomycin 6 gm qd
  • Metronidazole (Flagyl) 800 mg po qd
  • Ampicillin
  • L-dopa (Ann IM 1975;83:677)
  • Others like flumazenil (Romazicon) iv helps 25%; if oral becomes available, may be useful