Table 2 Clinical checklist: acute management of organic acidaemia (modified from Baumgartner et al. 2014 [3])

• Acute management is required any time a patient with an organic acidaemia has symptoms such as lethargy, vomiting, tachypnoea, and impaired vigilance.

• Laboratory testing (metabolic panel with ammonia, electrolytes, anion gap, lactate, ketone bodies in urine) can determine whether the patient needs urgent care. Plasma amino acids, urine organic acids and plasma acylcarnitine profile are useful to establish the cause of acute metabolic decompensation and to monitor long-term patient management.

• Immediate administration of sufficient calories (100–120 kcal/kg/day in infants, with lower amounts in older children) in the form of glucose and lipids is necessary during acute decompensation in organic acidaemias, although protein should be restarted as soon as possible (usually not later than 24–48 h). As the patient improves, a nasogastric tube should be inserted to administer enteral formulas containing limited amounts of proteins (0.5 g/kg/day). Enteral feeds should be gradually increased to provide adequate calories (100–120 kcal/kg/day in infants, with lower requirements in older children) and protein (increasing natural protein to 0.8–1.2 g/kg/day and then adding the balance of protein needed via medical foods without propionic acid precursors to reach the recommended daily allowance for age).

• Intravenous glucose may be given as 10% dextrose (D10), or 20% dextrose (D20) if a central line is available, together with appropriate salts (half-normal saline up to about 5 years of age, normal saline after 5 years of age; potassium chloride at 20 mEq/L if there is no evidence of hyperkalaemia), and intralipids 20% to provide adequate calories for age.

• In case of metabolic acidosis (sodium bicarbonate < 15 mEq/L), sodium bicarbonate is substituted for sodium chloride (75 mEq/L or 150 mEq/L), and potassium acetate (20 mEq/L) is substituted for potassium chloride. Serum bicarbonate and electrolytes should be monitored every 4–6 h and intravenous sodium bicarbonate should be switched to sodium chloride once serum bicarbonate reaches 25 mEq/L.

• If glucose becomes greater than 8.3 mmol/L, insulin should be given: 0.1 U/kg as a bolus, followed by 0.1 U/kg/hour as a drip. Insulin dose should be adjusted to maintain glucose levels 3.9–8.3 mmol/L.