Insulin Pumps and Continuous Glucose Monitoring. Francine R. Kaufman

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.

THE DISADVANTAGES OF PUMPS

      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 until you find what works for you. If you use the same site for the infusion set repeatedly, you can get scar tissue and an increase in fatty tissue buildup (called lipohypertrophy).

      Infusion Set Issues

      The probability of your infusion set falling out or being jarred from the site can be minimized with good habits. Using appropriate taping techniques and changing your infusion set regularly can help avert problems. To be safe, you need to keep extra pump supplies with you at school or work, and have an insulin pen or syringe available so you never have to compromise your safety and health.

      Missing Boluses

      Some people forget to bolus with meals or to correct hyperglycemia. If you regularly miss or skip taking a bolus for food, then your A1C will increase. The good news is that many pumps have alarms that you can set to remind you to test or take a bolus at certain times; an example might be to set a bolus alarm to remind you at lunchtime to check your glucose and take your bolus insulin. You can also set the alarm on your phone or watch to remind you about boluses.

      Weight Gain

      Some people gain weight due to the ease of dosing insulin. But the pump doesn’t add excess calories to your meal plan—only you can do that. Remember your meal plan, and schedule a meeting with a registered dietitian if you’re having trouble following your healthy eating plan.

      Cost

      The insulin pump itself, plus the supplies (e.g., infusion sets, insulin reservoirs, tapes), have a cost. Most insurance companies cover insulin pump therapy, minus your deductible. It is important for you to find out what you will have to pay out of pocket for insulin pump therapy before you make the transition.

      Summing Up the Disadvantages

      These disadvantages usually become less significant as time passes and as you become more familiar with the pump. As your knowledge and experiences grow, you will be able to adapt to the pump and make it work for you. Insulin pumps can be a great tool for diabetes management and can mean better glucose control and fewer complications.

WHAT MAKES YOU A GOOD PUMP CANDIDATE?

      Before anyone can take on an insulin pump, he or she needs to understand what the pump can do and how it works, be realistic about his or her capabilities, and know a good deal about diabetes management. Your diabetes team may be very enthusiastic about pump therapy for you, but are you ready for it? What do you need to do to be considered ready for an insulin pump?

      • Realistic expectations. The pump is not an artificial pancreas. It doesn’t cure diabetes. It cannot correct anything on its own. This is true even if you have a sensor and use CGM. You must be committed to being very active in your diabetes—and pump—management. Successful management takes time, good habits, dedication, hard work, and commitment.

      • No coercion. No one should be forced to get an insulin pump, including young children. Although a pump can motivate someone to participate in his or her diabetes management, this cannot be the primary reason to get a child or teen an insulin pump.