by Wesley W. Wilson, MD
NOTE: If you have any questions for "Ask the Doctor,"
please send them to the Voice editorial office. The only questions Dr. Wilson
will be able to answer are the ones used in this column.
Wesley W. Wilson, MD has retired as an Internal Medicine practitioner
at the Western Montana Clinic in Missoula, Montana. Dr. Wilson was diagnosed
with type 1 diabetes in 1956, during his second year of medical school. He remains
interested and involved in diabetes education for patients and professionals.
Q: I heard recently of a toddler on an insulin pump. Young children are so active,
I don't understand how this could work. Could you explain? And how young is
"old enough to use an insulin pump"?
A: Insulin pumps sound like "Gee Whiz" solutions to the problems persons
with diabetes have with insulin delivery. Pumps are really just sophisticated
devices that deliver insulin according to previously programmed schedules and
increase or decrease insulin delivery at the wish of the wearer or the person
in charge. Insulin delivery with a pump is much more flexible than with mixed
"depot insulin" and therefore should be more appropriate for the variable
exercise patterns of children. Most importantly, the pumps use only rapid-acting
insulin (Humalog, Novolog, or Regular). Depot insulins are those insulin types
formulated to release insulin slowly after injection, and include products such
as Humlin NPH or Lente, and similar Novolin products. All these products have
the nasty tendency to release more insulin during exercise, especially if injected
over exercising muscle, just when less insulin is needed. Note: I cannot speak
to the effect of exercise on the new, very-slowly-released insulin called "Lantus."
Rate of release of insulin into the blood is hard to accurately predict with
depot insulins--fast-acting insulins are much more predictable.
Another handy aspect of pumps is the ability to increase or decrease insulin delivery on demand, so that if exercise is planned, insulin can be reduced. Pump users can avoid the problem with depot insulin called the "Snickers effect"--that is the need for a load of sugar before and during exercise to avoid or treat hypoglycemia.
With all the above it seems that pumps would be ideal for kids; but there are potential problems. Training in the use of the pump is required -- and kids do differ in their ability to use these complicated devices. Parents also differ in their motivation and skill in using pumps, and in supervision, or trusting their children to do it right. Children face problems attending school while using insulin, and I would expect even greater problems at school with a pump. The age at which pump use is appropriate is hard to define and depends on a number of factors. It is true that more children are using the pumps and enjoying the added flexibility that pumps provide. A dedicated parent is essential.
Insulin pumps do have other problems. I'm a firm believer that if something can go wrong, it will. A pump user must carry extra supplies, and these can be expensive. Since pumps use only rapid-acting insulin, if the needle falls out, if there is a kink in the tubing, or if something fails in the pump, the blood sugar will rise rapidly, and in persons with type 1 diabetes, acidosis (DKA) may develop in six to eight hours. A pumper must carry emergency supplies not only for the pump, but also insulin and syringes, to allow insulin injections in the old way if the pump quits. These supplies should be carried if the pump wearer is away from home base for more than half a day.
I've been accused of "being compulsive about my diabetes supplies," since I try hard to have everything needed with me, when I'm away from home. This includes my pump supplies, glucose tester, extra strips, insulin and syringes. Despite my compulsion, while on a three-day weekend in Las Vegas, I discovered that I had neglected to bring extra pump supplies. I ran out on Saturday morning, so I called the pump manufacturer, who said the earliest they could get supplies to me was Monday afternoon. I then called lots of pharmacies, none of which carried any pump supplies. BIG trouble!
A heading in the yellow pages for the Diabetes Treatment Center
finally yielded results. Janet there didn't have the right supplies for my pump,
but she took charge and put me in touch with Diane at Desert Valley Hospital
on Flamingo Boulevard. Diane provided sufficient supplies to get me back home
to Montana. My thanks to those two caring, concerned and professional women!