My 3 1/2 year old son was diagnosed with ketotic hypoglycemia that he has had since between 12 and 18 months of age. Last week we spent 5 hours in the ER for IV dextrose because I could not bring it around at home. Upon arrival at the hospital it was 41 by fingerstick. Today he had a level of 57 in the middle of the morning 2 hours after a large glass of juice and a couple of helpings of cereal. Tonight after a big meal high in protein it is still only 79. Could something else be happening? When diagnosed they ran a CT scan of the brain and the blood test where they look at the history of his blood sugars. His UA does test positive for ketones.

To begin with any child who is fasted can develop a low blood sugar which in turn leads to a dependance on fat stores for energy and the production of ketones from the metabolised fatty acids. In most instances by far this is a transitory and quite normal process. Excluding neonatal hypoglycemia, there are two groups of circumstances in which hypoglycemia can reach the point of causing seizures and other neurological problems. The first group usually presents in infancy and may represent the consequences of an inborn error of organic acid or carbohydrate metabolism like hereditary fructose intolerance or branched chain ketoaciduria. These are very rare conditions; but just occasionally variants occur which can present later in childhood.

By far the commonest cause of serious hypoglycemia in childhood however is what is called ‘ketotic hypoglycemia’. It responds readily to giving glucose intravenously; but so far no specific metabolic defect has ever been defined and it tends to be thought of as just an extreme, but still essentially normal, response to a fall in blood glucose. This susceptibility decreases with age and perhaps for this reason and because immediate treatment is straightforward the rare metabolic problems are not usually looked for.

At some point, though, this may have to be reconsidered and you may have reached this point; but you will have to talk to your son’s pediatrician about this as the evaluation needs the help of a specialised metabolic laboratory. In the meantime I imagine that you are already maintaining a profile of blood sugars over the 24 hours so that you have an idea of the circumstances increasing the risk of hypoglycemia especially diminished appetite and unusually vigorous activity. You may have already discussed using glucagon with the doctor though it is less likely to be effective than in diabetic hypoglycemia. Also I am sure you are trying to give a bed time snack like half a Extend Bar which is high on protein and cornstarch.

Finally you may want to bear in mind the possibility of using a GlucoWatch. The present version seems likely to be approved soon by the FDA (it was approved by an FDA committee); but I think it might be still a little cumbersome for a three year old to wear on the leg. I am told though that the company hopes soon to have a smaller version. This system has a low blood sugar alarm which can be preset and linked to an alarm system in another room.

DOB