From the Guidelines
Hyperammonemia at a level of 64 requires immediate medical attention, as it can cause severe neurological symptoms and even death if left untreated. According to the consensus guidelines for management of hyperammonaemia in paediatric patients receiving continuous kidney replacement therapy 1, hyperammonaemia is defined as >100 µmol/l (170 µg/dl) in neonates or ≥50 µmol/l (85 µg/dl) in term infants, children, and adolescents.
Key Considerations
- The patient's ammonia level is below the threshold for severe hyperammonaemia, but still requires prompt treatment to prevent further complications.
- Treatment typically involves medications like lactulose and rifaximin to reduce ammonia levels, as well as intravenous L-carnitine in acute cases 2.
- Protein restriction to 0.6-0.8 g/kg/day is recommended initially, with gradual reintroduction as levels normalize.
- Patients should avoid medications that can worsen the condition, such as certain sedatives and diuretics.
Recommendations
- Initiate treatment with ammonia-scavenging agents, such as sodium benzoate and sodium phenylacetate, as recommended in Box 1 of the consensus guidelines 2.
- Consider continuous kidney replacement therapy (CKRT) or haemodialysis (HD) if the patient's condition worsens or if ammonia levels remain elevated despite medical treatment 3, 4.
- Monitor ammonia levels, liver function, and neurological status regularly during treatment, and adjust the treatment plan as needed.
Important Notes
- The underlying cause of hyperammonaemia must be identified and addressed to prevent further episodes.
- Patients should seek emergency care if experiencing worsening confusion, lethargy, or other neurological symptoms.
- Regular monitoring and follow-up with a healthcare provider are essential to ensure proper management of hyperammonaemia and prevent long-term complications.
From the Research
Hyperammonemia Significance
- Hyperammonemia is a severe condition that can lead to neurological damage and systemic complications if left untreated 5, 6, 7, 8, 9
- A level of 64 is considered significant and may require immediate medical attention to prevent life-threatening neurological injury 5, 6, 7, 8, 9
Clinical Considerations
- Hyperammonemia can be caused by various factors, including liver failure, inborn errors of metabolism, and other non-hepatic causes 5, 6, 7, 8, 9
- Patients with hyperammonemia may present with seizures, encephalopathy, or other neurological symptoms, and may be entirely asymptomatic in some cases 6, 8, 9
- Coma duration, ammonia peak level, and hyperammonemia duration are the main risk factors of hyperammonemia-related neurologic deficits and death 8
Treatment Options
- Haemodialysis or haemo(dia)filtration is the first-line treatment for acute severe hyperammonaemia (of any cause) in an adult 6, 7
- Ultra-high dose continuous veno-venous haemodiafiltration may be used to treat severe hyperammonaemia in patients with acute kidney injury (AKI) 7
- Intravenous ammonia scavengers may be used to treat hyperammonemia in patients who do not respond to oral medications 9
- Multidisciplinary management, including liaison with specialists in metabolics, gastroenterology, and dietetics, is crucial for optimizing patient care and outcomes in complex cases 9