An insulin infusion pump is a small device worn by some diabetics that dispenses fast-acting insulin through a set of tubes connected to needle, or cannula, inserted under the skin. This pump can deliver insulin at programmed intervals throughout the day, as well as in response to meals. An insulin infusion pump can be set for different patterns of infusion, from one big spike of insulin to a lower level delivered over a longer period of time. This is determined by the amount and kind of food that has been eaten by the person wearing the insulin pump.
By counting carbohydrates, a person with an insulin infusion pump can decide how much insulin to inject, and in what pattern. A higher-carbohydrate meal, which causes blood sugar to rise rapidly, might require a larger dose of insulin, delivered quickly. A higher-protein, lower-carbohydrate meal, which causes blood sugar to rise more gradually, might require a more regular dose, delivered slowly.
An insulin pump has some advantages over traditional insulin injection with a syringe or an insulin pen. Younger people, particularly children and teens with Type I diabetes, often find it easier to use a pump than to inject insulin. People who use an insulin infusion pump can eat as they want, instead of having to plan when and what to eat. Hypoglycemia is more easily controlled with an insulin pump, and A1C levels — the long-term measurement of blood glucose levels — often improve.
There are a few disadvantages to using an insulin infusion pump. It is typically more expensive than insulin injection. There are more parts to go wrong: the pump itself, the infusion set, and the cannula.
Insertion can be tricky, and the cannula can come out without the wearer noticing, which causes the insulin to not be delivered and can lead to diabetic ketoacidosis. Some physical activities like strenuous sports can also dislodge the pump or make it uncomfortable to wear. Still, many diabetics who wear insulin pumps find them more convenient and flexible than injection.
A continuous blood glucose monitor is a small device with a needle inserted under the skin that takes blood glucose readings at regular intervals. When combined with continuous glucose monitoring (CGM), an insulin pump can act almost like a normally functioning pancreas: It can release the proper amount of insulin in response to a high glucose reading. This combination shows great promise in the management of Type I and Type II diabetes.