Review Question - QID 202619

This patient is suffering from hepatic encephalopathy secondary to hypokalemia and should be treated with potassium.

Hepatic encephalopathy is a decline in mental status secondary to liver failure. It occurs when the liver is unable to clear the blood of toxic metabolites, especially ammonia. There are multiple factors that may cause a patient with liver failure to become encephalopathic -- one important one is hypokalemia. Other precipitating factors include alkalosis, the use of sedative or CNS-altering drugs, infection, and hypovolemia (e.g. from a GI bleed). Loop diuretics, such as this patient's furosemide, predispose to hypokalemia.

Potassium must be repleted immediately when hypokalemia precipitates hepatic encephalopathy. Recall that hypokalemia can also cause ventilatory failure, EKG changes, and arrhythmias. Immediate repletion of K is also indicated in these clinical scenarios.

Starr et al. reviews cirrhosis, hepatic encephalopathy, and the treatment thereof: "Causes of hepatic encephalopathy include constipation, infection, gastrointestinal bleeding, certain medications, electrolyte imbalances, and noncompliance with medical therapy. These should be sought and managed before instituting the use of lactulose or rifaximin, which is aimed at reducing serum ammonia levels."

Incorrect answers:
Answer 1: Dextrose is indicated for the treatment of hypoglycemia.
Answer 3: Lactulose is used to treat hepatic encephalopathy, but the underlying hypokalemia must be corrected first.
Answer 4: Neomycin, an aminoglycoside antibiotic, is used to treat hepatic encephalopathy. It kills bowel flora to reduce the production of ammonia. However, the patient's underlying hypokalemia must be treated first.
Answer 5: Hydrochlorothiazide (HCTZ) would worsen the patient's hypokalemia and is not indicated.