There’s no doubt that interest in insulin pumps is up among people with diabetes. In fact, the most commonly asked question of the staff at the Yale Children’s Diabetes Program in New Haven, Connecticut, is, “Am I a candidate for the pump?” or “Is my child a candidate for the pump?” In many cases, the answer is yes.
Let’s have a look at what makes a child a good candidate for a pump and what’s involved in getting started using one. As you read, keep in mind that this article describes primarily how the Yale Children’s Diabetes Program operates. As in all aspects of diabetes care, there are many “right” ways of doing things, and the diabetes center in your area may do things differently. If you are interested in any of the methods or products mentioned in this article, please check with your health-care team before making changes in your child’s diabetes-care routine.
Who’s a pump candidate?
The children who are most likely to be offered a pump at Yale are those who are working very hard to maintain normal blood glucose levels, those who are not meeting goals, those who ask about pump treatment and how it might help them, and those whose episodes of hypoglycemia or high blood glucose are affecting their school work, sports performance, and normal, day-to-day living.
However, pump treatment will succeed only if both child and parents are motivated and have reasonable expectations of what a pump can and can’t achieve. They must understand that a pump is only as good as the person operating it. In addition, parents need to be reliable, and a child must be willing to check his blood glucose level at least four times a day. In fact, a child or teen wouldn’t be considered for pump treatment at the Yale Program if this minimum requirement were not already being met.
Since many children are afraid of any change, a little persuasion is sometimes in order for a child to try a pump. It’s important to let a child know that pump treatment can help him feel better, have more normal blood glucose levels, perform better in school and sports, and have fewer episodes of hypoglycemia. He will also have much more flexibility in terms of mealtimes and food choices. And, if more normal blood glucose levels are achieved, the incidence of long-term complications of diabetes will be greatly decreased or eliminated.
Youth no object
The age of a child is a consideration for pump candidacy, but no age rules out the possibility of using a pump. I recently put Maggie, age 18 months, on an insulin pump. She was having difficulty with both high blood glucose and hypoglycemia at all times of day and night. Her blood glucose level would frequently drop overnight, even with no insulin in the evening. Her mother was checking her blood glucose levels eight to 10 times a day and was becoming very discouraged. Clearly, it was time to try other treatment options.
At the time of writing, there are 36 children under the age of seven on pump therapy in the Yale Program. Their reasons for starting on pump therapy have varied. Sometimes a child in this age group is doing well with insulin shots, but the parents would like the flexibility that the pump offers. Many parents would like to make mealtimes more pleasant and to not have arguments over food. (Even at their best, children in this age group tend to be finicky eaters.) They would also like to smooth out the blood glucose swings that are so common in a young child.
Once a child is three or four, he is able to deliver an insulin bolus (the dose taken before meals) himself, but he needs someone to verify the amount before activating it. When a child younger than seven is started on the pump, we usually use the block feature on the particular pump we use, which keeps the child from activating the buttons on his own. This feature is usually used only for the first week or so; after that, the novelty usually wears off, and the child doesn’t tend to play with his pump.
School-age kids (7 to 12 years old) are great pump candidates. They tend to be excited about the pump and want to help as much as possible. They also tend to be very successful at keeping their blood glucose level in the normal range most of the time. They can give bolus doses themselves but need some help deciding how much to bolus. They can begin counting carbohydrates and are able to use their insulin-to-carbohydrate ratio, as determined by their health-care provider, to tell how much insulin they require per carbohydrate exchange. (A carbohydrate exchange is approximately 15 grams of carbohydrate.) In general, kids this age are proud to show off the pump to their friends and think it’s quite cool to wear.
Teens are probably the least reliable group to start on the pump. Even though they easily learn how to use it and quickly pick up the mechanics, they are typically preoccupied with many other things, and the pump quickly goes down on the priority list. Teens frequently forget to bolus. They do better on the pump than they do with shots, but they don’t do as well as younger children.
If child and parent agree on the idea of pump treatment, the next step is to explain a little more about what the pump will and will not do. The child and parents are shown an insulin pump and how it works. This provides the opportunity to clear up any misconceptions about what pump treatment entails and to address any fears.
An insulin pump is a cell phone-size device that contains a cartridge filled with fast-acting insulin. Either Regular or lispro (brand name Humalog) can be used. Intermediate-acting and long-acting insulins are never used in a pump. Furthermore, since the pump delivers insulin continually, intermediate-acting and long-acting insulins are no longer needed in the insulin regimen.
In addition to the insulin cartridge, the pump also contains a tiny computer, which allows it to be programmed, a motor, which pushes insulin out of the cartridge and into the body, and a battery, which must be changed periodically. The pump is worn outside the body and is generally clipped to a belt or carried in a pocket or special pump pouch.
Attached to the pump is a length of tubing, through which the insulin flows from pump to body, and the infusion set: a small insulin needle or Teflon cannula that is inserted just below the skin and taped securely in place. The infusion set must be changed every second or third day to prevent infection. The new set is inserted into a different site on the body.
The pump is intended to be used 24 hours a day. A small amount of insulin is given continually (the “basal rate“), according to a programmed plan unique to each pump user. This insulin keeps blood glucose in the desired range between meals and overnight. When food is eaten, the user programs the pump to deliver a “bolus” of insulin that is matched to the amount of food that will be consumed. It’s important for prospective pump users to realize that the pump does not measure blood glucose levels, nor does it program itself. The user must do these tasks.
Children sometimes worry that the pump will fall out if they hang upside down on the monkey bars or during active sports. Parents tend to worry about their ability to learn something new, about having to inform their child’s school about something new, about hurting their child, and about the pump getting disconnected during sports. These and any other fears must be addressed in an adequate way to alleviate these concerns. Children and their families are told that they can still do anything they did before and that the diabetes team will be there to address any issues that arise once pump therapy is started.
All of the children who receive care at the Yale Program are started on the pump in the office during a one-hour visit scheduled on a Tuesday morning. The child’s total daily insulin dose is calculated and divided in half. One of those halves is further divided by 24, and this becomes the basal rate in units per hour. The other half is divided among the meals and snacks as bolus doses, with the larger proportion being given for breakfast, less for lunch, and more for supper.
After the pump start, the child goes to school as usual. The child or parents are instructed to check blood glucose levels at the usual times (before meals and at bedtime) and, in addition, at 12 AM and 3 AM. They phone in the blood glucose readings the following day and return on Thursday to do the infusion set change on their own with diabetes team members to coach.
During the first few weeks of pump use, the Yale Program social worker is available to discuss any adjustment problems that the child or family might be having. After approximately three to four weeks, the diabetes team (child, parents, and care providers) generally feel quite comfortable with pump treatment, and the initial trials and worries subside.
Nuts and bolts
There are now several insulin pumps on the market as well as a variety of styles of infusion sets and other accessories. (Click here for a list of insulin pump manufacturers.) Here’s how we do it at Yale:
Infusion sets. Children at Yale are instructed to insert the cannula into the upper, outer buttocks. This is the least painful site and has the most subcutaneous tissue. For very young children, Emla cream, a topical anesthetic, may be used. (Emla cream is not sold over the counter; it requires a prescription to purchase.) We don’t recommend this for long-term use, however, since we don’t know what the effects are of using it as frequently as every other day. Ice may also be used to numb the insertion area.
Insulin dosing. Once a person has begun using a pump, his basal rates and bolus doses can be fine-tuned. We have found that most children require a higher basal rate from 9 PM to 3 AM than at any other time of day. The 3 AM basal rate is the lowest. So a typical child on a total daily dose of 12 units would be on basal rate profiles similar to this: 12 AM, 0.3 units/hour; 3 AM, 0.1 units/hour; 7 AM, 0.2 units/hour; 9 PM, 0.4 units/hour. It’s possible that the 9 PM basal rate would need to be increased even further. We feel that this need for more insulin during the night is a result of growth hormone secretion during sleep. Typical bolus doses for this child would be 2.5 units for breakfast, 1.0 units for lunch, 0.5 units for snacks, and 2 units for dinner.
After the initial adjustment to the child’s usual routine, insulin-to-carbohydrate ratios can be investigated with the child, parent, and dietitian. Whatever the insulin-to-carbohydrate ratio is, this is usually the correction bolus to bring blood glucose down 100 mg/dl in the event of high blood glucose. For example, if a child has an insulin-to-carbohydrate ratio of 0.5 units to 15 grams of carbohydrate, 0.5 units of insulin would drop this child’s blood glucose level 100 mg/dl. If the ratio were 1 unit to 15 grams carbohydrate, 1 unit of insulin would usually lower the blood glucose level by 100 mg/dl.
Our rule of thumb for finding a child’s insulin-to-carbohydrate ratio is this: for children under 7 years old, use 0.5 units to 15 grams of carbohydrate. For children 7 to 12 years old, use 0.7 units to 15 grams of carbohydrate. For teens, use 1 unit to 15 grams of carbohydrate. These are just starting points, however. Insulin-to-carbohydrate ratios must be individualized for each child.
School, sports, and vacation
What happens when a child who uses a pump goes to preschool, day care, or primary school? Like any child with diabetes, a child using a pump needs to have an individualized plan of care that is agreed on by parents, teachers, and school administrators. The plan should cover both daily care and emergency care and specify who is responsible for what diabetes-care tasks.
Getting to specifics, most children do not need a bolus of insulin for a midmorning snack that contains 15 grams of carbohydrate. However, if a child who eats a midmorning snack consistently has high blood glucose at lunch, we program a basal rate increase for one hour before snacktime. For example, if the usual basal rate is 0.2 units/hour in the morning, we would make it 0.7 units/hour at 9 AM and set the basal rate back to 0.2 units/hour at 10 AM. By covering the snack this way, neither the child nor the teacher has to worry about a bolus dose. We do the same thing in school-age kids if coverage of a snack is necessary.
For young school-age children, the parent generally tells the school nurse or teacher what dose the child needs for lunch based on blood glucose level, food intake, and activity. The dose may be different if lunch is followed by gym or recess rather than an academic class. Most children, even three-year-olds, can program their own boluses with adult supervision.
For organized sports, the pump is usually removed. If the pump contains lispro, we recommend disconnecting for no longer than two hours without bolusing. If a child is at the beach, he may hook up and bolus every two hours or take a lunch shot of Regular insulin, which will usually last for four to five hours.
If a child lives at the beach in the summer, we can substitute Regular for lispro in the pump for the whole summer. It means a few days of re-regulating the child, but it isn’t usually a big problem and it allows him to go for four to five hours without having to hook up to the pump. (Note: If you currently use a pump, do not attempt to make this change on your own. Work with a health-care provider experienced in pump therapy.)
At the time of writing, the Yale Program has 250 children on the insulin pump – close to half of all the children we see. We initiate treatment with at least two children per week. The mean glycosylated hemoglobin (HbA1c) level for all children on pumps at our center is 7.2%. (The HbA1c test gives an indication of overall blood glucose control over the previous two to three months.) While a person who does not have diabetes generally has an HbA1c of 4.2% to 6.3% in our lab, research has shown that an HbA1c of 7.2% or lower in people with diabetes is associated with a much lower risk of long-term diabetes complications.
Our philosophy is that intensive management of blood glucose levels is essential right from diagnosis, so all of our children with diabetes are intensively managed regardless of their treatment method. The mean HbA1c for all of them is 7.7%. The 0.5% decrease – without hypoglycemia – seen in those using a pump is a significant improvement.
Our hope is that all pediatric diabetes programs will offer the pump option to their children and families. To quote many of the parents we see, “It gave us our life back.” What an inspiration for us to continue our pump program!