Because children receive such small doses of insulin compared to adults, accurate measurement is crucial. But doctors at Johns Hopkins Hospital reported in the January 1996 Diabetes Care that caregivers overdraw insulin by an average of 0.22 U.
Fifteen caregivers of children with diabetes were asked to deliver repeated small doses of insulin, including some doses separated by just 0.25 U. It was found that caregivers within a family delivered doses as variable as the general population. For example, one person’s estimate of 0.25 U was not the same as someone else’s.
In families with two or more caretakers, the combined variability of dosage was 40% greater than a single individual’s variability. The smaller the intended dosage, the more significant the error.
“Of our 15 participants, 10 were parents who shared the responsibility of injecting insulin for their child. In examining the consistency of different caretakers for the same child, we found that among the five spouse pairs there was as much variability as between unrelated subjects,” the study reported.
“Over the course of a week, a child may receive a predictable dose of insulin, but on any given day doses will vary by around 0.25 U in each direction. Therefore, it is possible that variations in dose delivery, especially with the small insulin doses needed in young children, may be one factor contributing to blood glucose variability.”
The researchers offered several possible ways to insure consistency in households with more than one caretaker. One can give the morning dose and the other, the evening dose. If the usual caregiver will not be available, he or she could pre-fill several syringes.
When a child is in the hospital it may be preferable for a regular caretaker to administer insulin rather than a nurse or other professional. Also, researchers say some people may find it helpful to use syringes with half-unit measurement marks.