Table 6 Management of symptomatic hyperammonemia in undiagnosed patients and known patients with MMA/PA

Increased > upper limit of normal

• Stop protein intake

• Stop protein intake

• Stop protein for maximal 24 (-48) hours

• Give iv glucose at appropriate dosage (see Table 7) to stop catabolism ± insulin^#

• Give iv glucose at appropriate dosage (see Table 7) to stop catabolism ± insulin

• Avoid exchange transfusions as cause of catabolism/protein load

• Monitor ammonia blood levels every 3 hours

• Increase carnitine dosage to 200 mg/kg/d

• Hyperglycemia can be extremely dangerous (hyperosmolarity)

• Monitor ammonia blood levels every 3 hours

100-250*

• As above

• As above

• Start drug treatment with i.v. arginine, sodium benzoate and sodium phenylbutyrate (see Table 7)

• Start drug treatment with sodium benzoate (see Table 7)

• If major hyperglycemia occurs with increasing lactate reduce glucose infusion rather than increasing insulin

• Start carbamylglutamate, carnitine, vitamin B₁₂ (preferably hydroxo-Cbl), and biotin (see Table 7)

• Consider carbamylglutamate (see Table 7)

• Avoid hypotonic solutions

250-500

• As above

• As above

• Add sodium and potassium according to the electrolyte results (cave hypokalemia when acidosis is corrected)

• Prepare extracorporeal detoxification if significant encephalopathy and/or early high blood ammonia level or very early onset of disease (day 1 or 2)

• Consider extracorporeal detoxification dependent on patient's age and history

• Take into account the sodium intake if sodium benzoate or phenylbutyrate is used^•

• Begin extracorporeal detoxification if no rapid drop of ammonia within 3-6 hours

• Avoid repetitive drug boluses

500-1000

• As above

• As above

• Monitor phosphate levels and supplement early esp. during hemodialysis

• Start extracorporeal detoxification immediately

>1000

• Evaluate whether to continue specific treatment or to start palliative care

• As above