A small, battery-powered pump designed to deliver insulin into the user’s body 24 hours a day according to a preset program. An insulin pump, which is about the size of a cell phone, is composed of a reservoir for the insulin, a small battery, a pump, and a thin plastic tube with a needle or soft cannula at the end through which insulin passes into the body. (Certain insulin pumps have a slightly different design without any tubing.) The pump continuously delivers a small amount of insulin (the “basal rate”) to help the body’s tissues make use of the glucose that is in the bloodstream all the time. Pump users can also deliver a larger “bolus” dose of insulin to cover the glucose that comes from the foods they eat.
Some people mistakenly believe that a pump is automatic and hassle-free. In fact, using a pump requires more care and vigilance than using traditional insulin injections. What pumps can offer, however, is lifestyle flexibility and the ability to control blood glucose very tightly. Standard insulin injection routines can be burdensome by restricting people’s schedules. For example, an injection regimen that calls for one or two shots a day of longer-acting insulin can require a person to eat his meals when his insulin is peaking. Insulin pumps, on the other hand, infuse a small amount of rapid-acting insulin continuously, so there is no real peak in insulin action with which one must synchronize meals. Pump users can schedule their meals whenever they want and simply deliver a “bolus” dose before they eat.
Insulin pumps can help improve blood glucose control as well. The fact that pumps continuously deliver rapid-acting insulin (much as a pancreas does) helps to avoid the highs and lows in blood glucose seen with some injection regimens. And the better blood glucose levels are controlled, the lower the risk of developing diabetic complications.
Insulin pumps are not for everyone. The best candidate for a pump is someone who currently takes two or more insulin injections per day and wants better control over his or her diabetes. The person must be willing to test blood glucose levels several times daily and be able to cope with the idea of being hooked up to a machine all day.