In advanced liver disorders, the following may increase ammonia levels: High-protein meals Gastrointestinal bleeding Hypokalemia Metabolic alkalosis Certain drugs (eg, alcohol, barbiturates, diuretics, opioids, valproate) High-dose chemotherapy Parenteral nutrition Renal insufficiency Extreme muscle exertion and muscle wasting Salicylate intoxication Shock Ureterosigmoidostomy Urinary tract infection with a urease-producing organism (eg, Proteus mirabilis) Because the degree of elevation in the ammonia level correlates poorly with severity of hepatic encephalopathy, this level has limited usefulness in monitoring therapy.