Illness, surgery or injury - MSUD

In MSUD, severe metabolic decompensation can occur at any time during diagnosis or in case of any physiological stress situation, such as intercurrent infection, surgery or trauma, high physical activity, and or combined with dietary non-compliance, poor oral intake or fasting.¹

The metabolic decompensation is due to the accumulation of toxic metabolites and results in metabolic decompensation. Seriously ill patients require aggressive nutritional management that might include dialysis, parenteral nutrition and/or tube feeding. Non-acutely ill patients can often be managed with a ‘sick day‘guideline, which provides instructions for preventing.

The goals of the dietary emergency regimen are:^1,2

Promotion of anabolism by a high caloric diet, up to 150% of usual energy intake
Stop or reduce natural protein intake of 50-75%
Continue of BCAA free amino acid supplement
Ensure adequate fluid intake (up to 150 ml/kg)
Electrolytes supplementation if required
Start tube feeding in case of poor intake

Every patient should receive a personal emergency plan consisting of:

Which action can be taken at home, and when to contact the physician or treatment center.
A solution of a glucose polymer, such as Fantomalt, which is rapidly absorbed, simple to administer, usually well tolerated.
The concentration of carbohydrate solution depends on the age and weight of the child and ranges from 10% (infants) up to 25% (children).
Fat emulsions can be added to this emergency solution, but might be less tolerated especially when the patient is vomiting. Adding a protein free feed, such as Protein free formula, Energyvits or Basic-P is another option.
Oral rehydration salts can be used in case of acute diarrhea, for a 4 hour rehydration period, which can be stopped after assessment or continued if a longer rehydration period, is required.
Fluids depend on the age, weight and clinical conditions of the child.

Age/years	Glucose polymer concentration % CHO	Energy/100 ml Kcal	Osmolality(mOsm/kg H₂O)	Suggested daily fluid volumes by age and weight
Up to 1	10	40	103	<6 months 150 ml/kg up to a maximum of 1200 ml
1-2	15	60	174	7-12 months 120-150 ml up to a maximum of 1200 ml
2-9	20	80	245	11-20 kg: 100 ml/kg for first 10 kg, plus 50 ml/kg for the next 10 kg
>10	25	100	342	>20 kg: as above for first 20 kg + 25 ml/kg thereafter up to a 2500 ml maximum

References:

GMDI: Nutrition Management guidelines for MSUD. https://southeastgenetics.org/ngp/guidelines.php
Blau N. Physicians’s guide to the diagnosis, treatment and follow up of Inherited Metabolic diseases 2014