From the Guidelines
To address high ammonia levels, particularly in pediatric patients, immediate initiation of ammonia-scavenging agents as outlined in the consensus guidelines is crucial, including i.v. sodium benzoate, sodium phenylacetate, and L-arginine hydrochloride, alongside stopping protein intake and ensuring adequate caloric supply. The management of hyperammonemia, as detailed in the study by 1, emphasizes the importance of prompt intervention to prevent neurological damage and other complications. Key components of the treatment include:
- Stopping protein intake to reduce ammonia production
- Administering i.v. glucose at an infusion rate of 8–10 mg/kg/min and i.v. lipids up to 3 g/kg daily to support energy needs
- Providing caloric intake of ≥100 kcal/kg daily
- Using i.v. sodium benzoate and sodium phenylacetate, with dosages adjusted based on weight (<20 kg or >20 kg), given over 90 min as a bolus then as maintenance over 24 h
- Administering i.v. L-arginine hydrochloride, with dosages varying based on the specific urea cycle disorder and patient weight
- Considering i.v. L-carnitine for patients with certain conditions, such as organic acidaemias
- Supplementing with vitamins, including B12 and biotin
The decision to initiate dialysis, such as intermittent HD or CKRT, should be based on the patient's clinical status, including the presence of severe encephalopathy, seizures, and the trend in serum ammonia levels, as guided by 1. Institutional preferences, availability of equipment, and the patient's overall condition also play a role in determining the dialysis modality. Regular reassessment of the patient's response to treatment, including ammonia levels and neurological status, is critical to adjust therapy as needed and prevent further complications.
From the Research
Ammonia High
- Ammonia is a major neurotoxin implicated in the pathogenesis, progression, and severity of hepatic encephalopathy (HE) 2
- Therapeutic management of HE involves reducing ammonia production and increasing its elimination from the blood and the brain 2
- Various anti-ammonia therapies with synergistic and complementary actions have been attempted for overt HE and for prophylaxis of the first and recurrent episodes of HE 2
Treatment of Hepatic Encephalopathy
- Rifaximin and lactulose have shown to be effective in the treatment of HE 3, 4, 5, 6
- Combination of lactulose plus rifaximin is more effective than lactulose alone in the treatment of overt HE 3, 6
- Rifaximin is superior for reducing the risk of HE-related hospitalization 5
Management of Ammonia Levels
- Lactulose is effective for the prevention of overt HE recurrence over the long term 4
- The addition of rifaximin to lactulose significantly reduces the risk of overt HE recurrence and HE-related hospitalization, compared with lactulose therapy alone 4, 6
- Reduction of ammonia levels is a key goal in the management of HE, and combination therapy with rifaximin and lactulose may be effective in achieving this goal 3, 2, 4, 5, 6