Lactulose Hepatic Encephalopathy — FRCA Final MCQ

Instant feedback + full explanation. One question, done properly.

EasyIntensive Care MedicineLactulose Hepatic EncephalopathyFRCA Final

A 72-year-old man (ASA III) in ICU with acute liver failure is being managed conservatively. His ammonia level is 185 μmol/L and he has grade III hepatic encephalopathy. Which medication is first-line for reducing ammonia levels in hepatic encephalopathy?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: D — IV L-ornithine L-aspartate

Lactulose is the first-line treatment for hepatic encephalopathy. Mechanism: (1) lactulose is metabolised by colonic bacteria to lactic acid, lowering colonic pH which converts ammonia (NH3) to non-absorbable ammonium (NH4+), trapping it in the gut lumen, (2) osmotic laxative effect accelerates gut transit, reducing time for ammonia absorption, (3) may alter colonic bacterial flora. Dose: 15-30 mL 2-3 times daily, titrated to 2-3 soft stools per day. Rifaximin (non-absorbable antibiotic) is added as second-line or for prevention of recurrent episodes. In ICU, lactulose can be given via NG tube or as enema.

Reference: BSG – 2019 – Hepatic encephalopathy guidelines; NICE – 2022 – Cirrhosis management