My three year old daughter was recently diagnosed with type 1 diabetes, and her blood sugars frequently in the very high 400s mg/dl [22.2 mmol/L], and sometimes even too high for a meter reading. I don’t want to be calling the doctor all the time, but when do I really need to be concerned? What blood sugar is too high?

Different physicians have varying thresholds as to when they wish to be notified for patients’ glucose levels. Much may depend on the patient’s age, and much depends on the physician’s comfort level and degree of expertise. Hopefully, your three year old has had consultation with a pediatric endocrinologist. Your question is best addressed to that individual physician.

From my perspective, families can work within a framework of sorts: if the glucose reading is greater than 240 mg/dl [13.3 mmol/L] there should be some check for ketone formation. This can be done in the urine with a chemical ‘dipstick’ and some meters will read blood for ketones with the appropriate stick. If there are negative, trace, or even small ketones in the urine, I think families can address this at home by encouraging extra water to drink and then being certain to recheck blood glucose and ketones in another four hours to see if things are worsening. The presence of moderate or large ketones in the urine spurs me to have the patient receive additional fast-acting insulin (Regular, Humalog, or NovoLog) with the type and dose depending on the individual instructions you’ve been given, your experience, and your comfort level. Some of my patients prefer professional guidance there.

High glucose and no ketones? Then start to look for a pattern of glucose readings: recurring highs (or lows) at specific times of the day suggest that a reassessment of the insulin dose or meal plan is in order. Again, you would be advised to discuss with your child’s pediatric endocrinologist.

DS