What Is an Insulin Pump?
Designed to mimic a pancreas, an insulin pump continuously delivers tiny doses of insulin to your child's body, and it replaces the need to give daily injections of insulin with syringes or pens. The insulin pump is a mechanical device that is worn outside the body. It must be prescribed by your child's healthcare provider and requires training and education to use, just like most new therapies. The insulin pump has a computer inside that allows it to be programmed to deliver insulin in a variety of ways. An insulin pump only uses rapid-acting insulin. There is no need for long-acting insulin while using an insulin pump. Get a doctor discussion guide.
An insulin pump is about the size of a small cell phone that is worn externally and can be discreetly clipped to your belt, slipped into a pocket or hidden under your clothes. It has a reservoir to hold insulin and tubing to take the insulin from the reservoir to your child's body through a cannula (short, flexible plastic tube) that is placed under the skin and held in place with an adhesive. The cannula is inserted into the same places that your child gets insulin injections. The cannula and tubing together are called an infusion set. The Medtronic reservoir and infusion set, for example, can be worn for up to three days at a time, so there's no more need to administer insulin shots multiple times a day. The insulin pump also uses a battery for power.
Insulin pumps help calculate and recommend insulin doses for meals when you enter your child's carbohydrates and current blood sugar. Your child is probably active, with insulin needs that vary throughout the day. An insulin pump provides schedule flexibility by allowing you or your child to set different insulin delivery rates based on your child's insulin needs. An insulin pump is controlled by the child/parent, and current insulin pumps do not automatically change the insulin dose being delivered based on blood glucose (BG) levels.
How Does an Insulin Pump Work?
An insulin pump must be programmed to deliver insulin in two ways, basal or background insulin delivery, which replaces long-acting or intermediate-acting insulin, and bolus delivery, a burst of insulin given with food or to correct a BG level that is higher than the user's target.
Basal insulin refers to the continuous release of insulin that the body needs between meals and during sleep to cover the basic need our body has for glucose to enter the cells for energy. With an insulin pump, the basal insulin delivery can be pre-programmed to meet individual needs. These basal doses (also called basal rates) run every hour, 24 hours a day. There can be multiple basal rates, the insulin delivery can be suspended for a period of time, or a temporary basal rate can be used for a specific amount of time. This is very different from taking one or two injections of long-acting or intermediate insulin. Once a subcutaneous insulin injection is given, the dose of insulin and the rate at which that insulin will work must continue — it can't be removed from the body.
Bolus insulin is a larger amount of insulin that is needed to balance food (mainly carbohydrates) that is eaten and to help get BG back into target range if it gets higher than desired. Bolus insulin is generally given from the pump before meals and snacks. The bolus dose is determined using a calculator inside the insulin pump. Using the current BG level and the number of grams of carbohydrate that are going to be eaten, it can then provide the dose needed for both food and to correct high BG levels. A bolus dose can also be taken when your child wants to eat more carbohydrates during a meal without giving another injection, or to correct an elevated BG. The insulin pump has a tracking function to monitor the active insulin that your child's body is still absorbing. This helps to prevent the "stacking of insulin," which can occur when insulin is administered based on a glucose value and there is still previously given insulin working to bring down the glucose, and the risk of a low BG.
The Medtronic insulin pump has a special feature that can be used to deliver your child's bolus insulin in a few different ways. It can deliver it normally (all at once), deliver it over a set amount of time, or deliver a portion now and another portion over time. Different foods might require different types of insulin delivery, and an insulin pump allows this.
Other special functions of the Medtronic insulin pump include allowing you to enter a "Missed Bolus Reminder" to help your child remember to take a bolus of insulin for a meal. This alert can be set if insulin is not given during a window of time. Another function can be entered to remind you or your child to check a BG two hours after eating to see if the insulin and food matched for that meal.