VLCAD

Acronym for Very Long Chain-Acyl-coenzyme A dehydrogenase Deficiency.

Rare. Mitochondrial metabolic disease. Autosomal recessive transmission of a deficiency of the enzyme that initiates the β-oxidation of  very long chain fatty acids (C14 - 20). 

Clinical presentations are variable according to the level of active enzyme:

-         neonatal, severe form: hypertrophic cardiomyopathy (reversible if adequate treatment is quickly introduced), metabolic acidosis, hypoglycemia, myopathy (lipid clusters at the biopsy)

-         infantile form: outbreaks of hypoglycemic coma without ketonemia in case of fasting or fever, acute fatty liver  disease (Reye-like syndrome), sudden infant death syndrome, epilepsy with organic aciduria  

-         little or asymptomatic form, known as the adolescent or adult form: muscle cramps in case of prolonged fasting or effort. Keep that possibility in mind in case of a rhabdomyolysis or a post-anesthetic coma.

Treatment: avoid any catabolism with a diet rich in slow carbohydrates and with a low content in fat (only short or medium chain fatty acids are allowed) and proteins; exogenous supply in carnitine (and occasionally riboflavin) is associated to correct a primary or secondary deficiency


Anesthetic implications: 

preoperative echocardiography; basal level of CPK and renal function;  glucose 10% IV administration, to avoid lipolysis, at the start of the fasting period: 6 mg/kg/h in children (8 mg/kg/h in case of stress) and 2 mg/kg/h for adults [in case of hyperglycemia, add insulin rather than decrease the intake of glucose]; the usual dose of carnitine on the morning of the intervention; monitor blood glucose levels.

Anxiolytic premedication to avoid undue stress.

Use of propofol ? Use preferably a solution with medium chain fatty acids (Propofol® and Diprivan® formulations  mainly contain long chain fatty acids) and avoid using it in continuous infusion because propofol inhibits complex II of the respiratory chain and the  intramitochondrial transport of long-chain fatty acids by carnitine. Increased risk of 'propofol infusion syndrome' (PRIS) ?

No risk of rhabdomyolysis with halogenated agents. Avoid succinylcholine: risk of rhabdomyolysis. Tourniquets ?

Caution with NSAIDs.


References : 


Updated: February 2018