A nurse is preparing to administer a dose of lactulose to a client who has cirrhosis. The client states, "I don't need this medication. I am not constipated.”. The nurse should explain that in clients who have cirrhosis, lactulose is used to decrease levels of which of the following components in the bloodstream?

Choice A rationale Lactulose's primary mechanism of action in a client with cirrhosis is not to lower potassium levels. While electrolyte imbalances can occur in cirrhosis, lactulose is a synthetic disaccharide that acts as an osmotic laxative, increasing peristalsis. Its main function is to decrease the production and absorption of ammonia in the colon to manage hepatic encephalopathy, not to significantly affect potassium balance. Choice B rationale Lactulose can be metabolized by gut bacteria, producing lactic acid and acetic acid. This process lowers the pH of the colon contents, which is beneficial for trapping ammonia as ammonium. However, the goal of therapy is ammonia reduction, not lowering bicarbonate. Furthermore, the pH decrease is localized to the gut lumen and does not significantly impact systemic serum bicarbonate levels. Choice C rationale Lactulose is used in cirrhosis to decrease serum ammonia levels and treat or prevent hepatic encephalopathy. Gut bacteria metabolize lactulose into organic acids, which lowers the colonic pH. This acidic environment traps ammonia (NH_3) as non-absorbable ammonium ions (NH_4+), which are then excreted in the stool, thereby lowering the toxic NH_3 levels in the bloodstream (normal range 15-45 μg/dL). Choice D rationale Lactulose is a sugar that is minimally absorbed systemically, and its use is not intended to treat hyperglycemia. While it is metabolized by gut flora, it does not have a direct, significant role in lowering serum glucose levels. Management of elevated glucose in cirrhosis would typically involve diet, exercise, and standard antihyperglycemic agents, not lactulose therapy