Thiamine Dosage for NASH-Related ACLF
For patients with NASH-related Acute-on-Chronic Liver Failure (ACLF), intravenous thiamine should be administered at 100-300 mg/day for at least 3-4 days from admission, followed by oral maintenance therapy of 100-250 mg/day. 1
Initial Assessment and Treatment Approach
- NASH is the most rapidly growing etiology for ACLF-related hospitalizations in the United States, with a 63% increase between 2006 and 2014 2
- Patients with ACLF should be admitted and monitored frequently, preferably in an ICU setting 3
- Nutritional assessment should be performed on all ACLF patients at ICU admission using tools such as the NUTRIC score 3
Thiamine Dosing Protocol for NASH-Related ACLF
Acute Phase (Hospital/ICU Setting):
- Administer 100-300 mg thiamine IV daily for 3-4 days from admission 1
- Thiamine should be given before administering any glucose-containing IV fluids to prevent precipitating acute thiamine deficiency 1, 4
- For patients with encephalopathy of uncertain etiology, consider higher dosing of 500 mg three times daily intravenously 1
Maintenance Phase:
- Following IV administration, transition to oral thiamine 100-250 mg/day 1, 5
- For patients with confirmed deficiency, maintenance dose should be 50-100 mg/day orally 1
Route of Administration Considerations
- For acute ACLF, the IV route is preferred initially due to potentially impaired absorption in critically ill patients 1
- Once the patient stabilizes, transition to oral route is appropriate if gastrointestinal function is intact 1
- For patients who cannot be fed orally, enteral nutrition via nasogastric/nasojejunal tube is recommended as first-line 3
Nutritional Support in NASH-Related ACLF
- Standard enteral formulas can be given, as there are no data supporting disease-specific formulations 3
- Enteral nutrition should be started with low doses independent of the grade of hepatic encephalopathy 3
- Parenteral nutrition should be used only as second-line treatment when adequate oral/enteral nutrition cannot be achieved 3
- Energy requirements should initially target 12-25 kcal/kg, evolving toward higher targets as the clinical course improves 3
- Protein restriction is not recommended; standard ICU protein support is indicated 3
Monitoring and Follow-up
- Monitor serum electrolytes (potassium, magnesium, phosphorous) before initiating nutrition and frequently for the first 3 days to detect refeeding syndrome 3
- Thiamine status can be determined by measuring RBC or whole blood thiamine diphosphate (ThDP) when available 1
- Be vigilant for signs of thiamine deficiency, which may manifest as cardiovascular, neurological, or metabolic abnormalities 1, 6
Special Considerations
- No upper limit for thiamine toxicity has been established; excess thiamine is excreted in urine 1
- High IV doses rarely cause anaphylaxis; doses >400 mg may induce nausea, anorexia, and mild ataxia 1
- For patients with refeeding syndrome risk, administer 300 mg IV before initiating nutrition therapy, then 200-300 mg IV daily for at least 3 more days 1
While there is limited evidence specifically addressing thiamine dosing in NASH-related ACLF, following the general guidelines for high-risk/critically ill patients is appropriate given the severity of ACLF and its metabolic demands 1, 7.