Insulin pump therapy adjustments for Isak

Isak’s blood sugar (BS) has been generally high for about a week now.  Usually prolonged high BS is related to an illness of some sort, however after a week of high BS there are no signs of any illness.  High BS increases the risk of long term diabetic problems as well as a short term risk of ketoacidosis, especially for insulin pump users like Isak.  So more insulin is needed, possibly because the last of Isak’s own insulin producing cells in his pancreas are shutting down.

To try and bring down his high BS we’ve increased his hourly insulin basal dose by 0.1 units.  That is roughly a 100% increase during the night and 33-50% during the day - in other words, a lot.  However, it doesn’t seem to be enough and we’re still having to correct high BS during both day and night.  We therefore need to further increase both his basal dosage and bolus dosages.

Bolus adjustments

A bolus is the insulin dosage Isak gets either with meals or to correct high BS.

Isak’s bolus insulin quotas are currently:

- 0.1 units per 3g carbs
- 0.1 units lowers BS by 1.5mmol

However, I worked out recently that 3g carbs would typically raise BS 2.5mmol for a 16kg child.  This indicates that 0.1 units per 3g of carbs is too low, something more like 0.1 units per 2g might be better.

The insulin dosage for a 20g carbs meal would then increase from 0.7 units to 1.0 units, and a 30g carbs meal from 1.0 units to 1.5 units.  This increase roughly reflects the insulin corrections we’ve been giving Isak a couple of hours after meals.

Basal adjustments

His basal dosages (including the 0.1 increase) are currently:

00-01: 0.15
01-02: 0.2
02-03: 0.15
03-08: 0.2
08-10: 0.35
10-12: 0.4
12-22: 0.35
22-00: 0.25

Last night at 00:59 Isak’s BS was 14mmol.  We gave him a 0.4 unit correction which only brought his BS down to 12mmol by 03:41.  We would have expected a drop of 4-6mmol rather than 2mmol.  So Isak received an extra 0.2 units insulin to bring down his BS some more and between 03:41 and 08:48 Isak’s BS dropped from 12mmol to 5mmol.  This is difficult to interpret, however my best guess is that Isak needs a little more insulin in the early night time, but probably gets enough in the early morning.  So we’ll increase:

22-00: 0.3
00-01: 0.2
02-03: 0.2

Which will give Isak an extra 0.2 units overnight.
 
Total daily insulin requirements

Assuming Isak eats around 100g carbs a day (20g breakfast, 30g lunch, 30g dinner, two snacks at 10g each), that makes his total insulin bolus for food 5.0 units.  The total basal dosage is 7.0 units.  Altogether 12 units per day.

Considering that not so long ago his total insulin requirement was roughly 6 units per day, it’s a big increase.  Trying to stay on top of this is hard work, as his insulin requirements seem to fluctuate on a weekly basis.

Note: Isak is 3 years old and has juvenile (type 1) diabetes and uses an insulin pump.