Hyperammonemia/ Refractory -Encepalopathy

Refractory Hyperammonemia / Hepatic Encephalopathy (ICU Algorithm)

Use when ammonia stays high or mental status isn’t improving (treat clinically; ammonia levels are supportive, not targets).

1) Immediate Actions & Goals

• Airway/O₂/CO₂ Optimize oxygenation/ventilation; check ABG/VBG.
• Stool goal Titrate therapy to 2–3 soft stools/day.
• Pain Adequate analgesia; avoid sedatives/anticholinergics.
• Electrolytes Correct hypokalemia & alkalosis.

2) Optimize Lactulose

• PO/NG: 20–30 g q1–2h until BM, then 10–20 g q6–8h (2–3 soft stools/day).
• PR (enema): 300 mL lactulose + 700 mL water/NS, retain 30–60 min, repeat q4–6h.
• Ensure no bowel obstruction; PEG-ELS if stool burden large.

3) Add Rifaximin

• Rifaximin 550 mg PO BID (start now if lactulose alone insufficient).
• If unavailable: short course neomycin or metronidazole (toxicity risk).

4) If Still High

• PEG-ELS 4 L over ~4h (rapid catharsis).
• L-ornithine L-aspartate (if available).
• Zinc if deficient.
• TIPS? Consider revision if recalcitrant HE.

5) Precipitant Checklist

• GI bleed / constipation / infection
• Electrolytes: ↓K⁺, alkalosis
• Renal failure / dehydration
• New meds: benzos, opioids, anticholinergics

6) Dialysis/CRRT

• Acute liver failure with cerebral edema or ammonia >150–200.
• Refractory HE with renal failure or volume overload.
• Urea cycle disorders, valproate toxicity.