From the Research
Treatment of elevated ammonia levels following transaminitis related to rhabdomyolysis should prioritize reducing ammonia production and enhancing its elimination, while addressing the underlying muscle breakdown. The primary goal is to reduce ammonia production and enhance its elimination while addressing the underlying rhabdomyolysis. Start with lactulose 20-30g (30-45mL) orally every 6-8 hours, titrated to achieve 2-3 soft bowel movements daily, as supported by the study on the use of quantitative modeling to elucidate the roles of the liver, gut, kidney, and muscle in ammonia homeostasis 1. Add rifaximin 550mg orally twice daily to reduce gut bacterial ammonia production. For severe hyperammonemia (>100 μmol/L), consider L-ornithine L-aspartate (LOLA) 20g IV over 4 hours daily for 3-5 days, as shown to be effective in reducing venous ammonia concentration after TIPSS 2. Ensure adequate hydration with IV fluids (normal saline at 150-200 mL/hour) to treat the underlying rhabdomyolysis and promote renal clearance of myoglobin. Monitor creatine kinase levels, renal function, and electrolytes closely, as abnormal liver function tests are frequently observed in cases of severe rhabdomyolysis 3. Protein restriction to 0.5-0.8g/kg/day may be temporarily necessary in severe cases. These interventions work by reducing ammonia production in the gut, enhancing its conversion to urea, promoting its excretion, and addressing the muscle breakdown that contributes to ammonia accumulation, as discussed in the context of pharmacotherapy for hyperammonemia 4. Treating the rhabdomyolysis itself through hydration and electrolyte management is essential for resolving the hyperammonemia, and the use of molecular adsorbent recirculating system may be beneficial in severe cases, although its mechanism appears to be independent of ammonia 4.
Some key points to consider:
- The pathogenesis of hyperammonemia is complex and involves multiple organs, including the liver, gut, kidney, and muscle 1.
- Lactulose and rifaximin have a proven role in reducing ammonia production and enhancing its elimination 4, 1.
- L-ornithine L-aspartate (LOLA) may be effective in reducing venous ammonia concentration after TIPSS 2.
- Abnormal liver function tests are frequently observed in cases of severe rhabdomyolysis, and serum aminotransferases lack tissue specificity to allow clinicians to distinguish primary liver injury from muscle injury 3.
- Protein restriction may be necessary in severe cases to reduce ammonia production 4, 1.
Overall, a multi-faceted approach is necessary to treat elevated ammonia levels following transaminitis related to rhabdomyolysis, and should prioritize reducing ammonia production and enhancing its elimination, while addressing the underlying muscle breakdown.