body. There is a needle that places a small cannula under the skin, and this needle then retracts back, so it is no longer in the body. These pumps have a separate controller that communicates with the motor in the patch to control insulin release. There is no display screen on the patch; all interactions are made through the controller, which wirelessly transmits the commands to the patch pump.
Those are just the basics. As we go on, you will learn more about what pumps can do, how they work, and what other features pumps have.
Insulin pumps can be used to effectively manage your diabetes. They can help you achieve your blood glucose and A1C targets. They give you flexibility. Many people feel as if their quality of life has been enhanced by insulin pump therapy, and they feel like they are more in control. Let’s go over what else insulin pumps offer.
Multiple Basal Rates
Multiple basal rates can be used to avoid high and low glucose levels. Many people have specific patterns that can be addressed by changing their basal rates throughout the day and night. For example, if you have the dawn phenomenon (high blood glucose in the morning), then increasing the basal insulin rates at 3:00 A.M. may help you avoid it. If you go to the gym in the afternoon, basal rates can be decreased to avoid hypoglycemia. Adjustable rates can also be helpful if you have hypoglycemia unawareness (you don’t recognize the signs of low blood glucose), gastroparesis (a digestive disorder), or an unpredictable lifestyle.
Temporary Basal Rates
Pumps allow you to temporarily change basal insulin delivery. You can either increase or decrease it. This helps when you are ill (when you are not eating and are at risk for hypoglycemia), have high blood glucose from stress, have exercised more than usual, or are traveling across time zones. In addition, you can use temporary basal rates to help treat highs and lows as they occur.
Multiple Basal Patterns
You can have more than one 24-hour basal pattern from which to select. For example, when insulin sensitivity changes with menstruation (for women), you can program a separate 24-hour basal pattern that increases basal delivery all day long. You can have separate 24-hour basal patterns for weekdays and weekends (when you want to sleep in), for traveling, or for summer vacation.
Avoidance of Long-Acting and Intermediate-Acting Insulin
You use only rapid-acting insulin in the pump. If you use injections, you use long-acting or intermediate-acting insulin in addition to rapid-acting insulin. In an ideal world, long-acting insulin would be absorbed evenly over many hours, without any peak effect. Similarly, intermediate-acting insulin (or NPH insulin) has peaks that are supposed to be timed to meals. But neither of these insulins is completely predictably absorbed from one day to the next. This variation in insulin absorption may contribute to unexplained high and low glucose levels that can be seen with injection treatments; these fluctuations in blood glucose levels are less frequent with insulin pump therapy.
Precision in Insulin Delivery
Pumps deliver insulin with precision, particularly when compared with insulin injections. Insulin pumps can deliver very small amounts of insulin, as low as 0.025 unit. By contrast, the lowest a syringe can deliver accurately is 0.5 unit.
Dosing for Food Intake
Choosing the right dose of insulin for a meal is a huge challenge, particularly if you eat out a lot, like to snack, or aren’t sure what’s in your foods. With a pump, you can take multiple boluses by pressing a few buttons, in case you eat more than you planned. You can take one bolus to start with and then take another if you realize the portion you ate was more than you had intended. (Just be careful that you don’t take too many boluses.) An insulin pump also makes it much easier to take your dose before you begin to eat, which can be difficult when you are in public and have to give yourself a shot.
Bolus Calculators
Most insulin pumps have bolus calculators that help determine how much insulin is needed for food and for correcting hyperglycemia. By programming your insulin-to-carbohydrate ratio and correction factor (how much insulin you need to bring high glucose down to the intended range) into the pump, the bolus calculator will do the math and provide you with an estimate of how much insulin you need to give.
Dosing to Correct Hyperglycemia
Because the pump already has your programmed insulin correction factor, it is easier to take a bolus to correct a high glucose level. Once the glucose level is entered into the pump, the pump will calculate how much insulin is needed. With the push of a few buttons, treatment for hyperglycemia is on the way.
Weight Management
Some people can improve their weight, if they need to do so, with an insulin pump. This can occur if the person experiences less hypoglycemia and no longer needs to consume extra carbohydrate to treat it.
Child Safety Features
Many insulin pumps have features that protect children from accidentally delivering extra insulin or changing pump settings.
Summing Up the Advantages
You can eat when you want, be active when you choose, wake up when you want, take multiple boluses, have options for basal infusion rates, and get help with insulin dose calculations. This should lead to better diabetes control, more glucose levels within your target range with fewer highs and lows, better A1C, and a better journey with diabetes.
Even though there are many advantages to insulin pump therapy, there are some disadvantages. Understanding them is important, because deciding to go on insulin pump therapy should be a carefully considered decision.
Risk of Diabetic Ketoacidosis (DKA)
Because the pump only uses rapid-acting insulin, if there is an unexpected or accidental interruption of insulin delivery, there may not be enough insulin in the bloodstream to stop the liver from releasing glucose and producing ketones. This can rapidly progress to DKA, which is a serious medical condition. By closely monitoring glucose levels, checking for ketones, and dosing insulin to bring glucose and ketone levels down, DKA can be avoided. You can find out more about DKA in chapter 9.
Being Attached
Some people feel apprehensive about wearing an insulin pump all day, every day, and about being attached to a device, no matter how small it is. This was probably a bigger issue before we all became comfortable having cell phones with us 24/7. The insulin pump will be attached to you, and for some people that is a constant reminder that they have diabetes. Try to view the insulin pump as a key to good control and a healthy, more normal life.
Privacy
People can see your insulin pump, unless you conceal it. The pump will make it difficult to hide the fact that you have diabetes. If you are reluctant to let people know about your diabetes, then this is something to consider before starting insulin pump therapy.
Skin Issues
The infusion set and the tape can irritate the skin. To use a pump, you may have to try different combinations of tape and skin treatments
