-Interview by Shahd Husein
We’re answering questions about type 1 diabetes and blood sugar management in a Q&A series featuring diabetes care and education specialists.
Today, we’re getting the scoop on insulin pumps from Ashlee Ernst. Ernst works as a pediatric diabetes educator at the Barbara Davis Center for Diabetes in Denver, Colorado. At the age of nine, Ernst was diagnosed with type 1 diabetes and has been on insulin pump therapy for 15 years.
The team at Barbara Davis Center actively participates in the T1D Exchange Quality Improvement Collaborative.
What is an insulin pump?
An insulin pump is typically a small box, around 2-2.5 inches by 3-4.5 inches, that pumps insulin under the skin, and can replace the need to give insulin injections with pens or syringes.
Insulin pumps are loaded with rapid-acting insulin, and slowly deliver a continuous infusion, or basal rate to replace basal insulin injections. They also deliver boluses, which are larger, rapid doses, for meals and blood sugar corrections.
People with diabetes program basal rates, correction settings, and meal dose settings to vary by time of day, which can make it easier to tailor insulin needs to the body’s diurnal rhythm and make dose calculations quickly. The pump uses these settings to calculate insulin doses, which the user can deliver or modify.
What are the different parts of an insulin pump and what are they responsible for?
The interface is a touch screen or button pad with a display that allows you to input settings, bolus insulin and, if connected to a continuous glucose monitor (CGM), see the current blood sugar reading. The reservoir holds a two-day to three-day supply of insulin.
Most pumps connect to the body with an infusion set, which is the tubing and a hub that sticks to the body and holds a cannula under the skin. Infusion sets need to be changed every 2 to 3 days. In the case of the Omnipod pump, there is a separate tubeless piece (called a POD) that sits on the skin and is controlled wirelessly from a separate device with an interface.
How do people with type 1 diabetes use an insulin pump?
Once an individual’s settings are programmed into an insulin pump, a person with diabetes will input their blood glucose and carbohydrates into the system, and it will calculate the recommended dose. The user can accept the dose or modify it and then deliver the bolus.
What are the pros and cons of using an insulin pump?
Some advantages of insulin pump therapy include:
-The ability to give smaller doses of insulin, between 0.1 to 0.025 unit increments, than injections; this is helpful for younger individuals.
-The ability to give insulin doses with fewer injections.
-The administration of insulin is easier and faster than with a pen or syringe and vial.
-The adjustment of basal rates throughout the day, due to the replacement of long-acting insulin with smaller, hourly doses of rapid-acting insulin.
Some disadvantages of insulin pump therapy include:
-The feeling of having another device connected to the body.
-The rare cases when an insulin pump breaks. Thus, it is important to know how to transition back to injections if an insulin pump needs to be replaced.
What insulin pumps are currently on the market in the United States?
The insulin pumps that are currently available include Omnipod (Omnipod Eros and Omnipod DASH), Tandem (t:slim X2), and Medtronic (MiniMed 670G and MiniMed 630G).
What features or options should someone consider if they are interested in using an insulin pump?
Younger patients need to consider minimum basal insulin amount and dosing increments. Those who need larger amounts of insulin should consider whether the reservoir can hold enough insulin for three days.
Other important decision points are whether to have CGM integration and whether to have the pump connected with a small hub and tubing or to have it connected directly to the body.
Another possible feature for some pumps is the suspension of basal insulin if a CGM is predicting low blood sugar or detects a low. There also are features where the insulin pump will increase the basal rate if the blood glucose levels are running above the target blood glucose. None of these features replace treating low blood glucose levels or bolusing for meals.
And while choosing a pump is a decision that should really be between you and your healthcare team, your insurer may limit your options.
All three current manufacturers and several other companies who are planning to enter the market are working hard to “close the loop,” by connecting a CGM with an insulin pump and a controller device to automatically calculate and deliver insulin without input from the user. Some of these features are currently available, with options expected to expand in the next one to two years.
Why should someone wearing an insulin pump rotate their infusion set site locations?
It is important to rotate an infusion set for better insulin absorption and to prevent lipohypertrophy, or abnormal fat buildup that is caused by giving insulin in the same place repeatedly. This is why providers inspect insulin injection sites and remind you to rotate.
What might someone with insurance expect to pay for an insulin pump? And what if that person had to pay out of pocket?
The coverage of an insulin pump through an insurance company differs greatly between plans. The out-of-pocket cost for an insulin pump alone can be around $7,000.
How often can/should someone with a pump upgrade or change pumps?
Insulin pumps typically have a four-year warranty, and it does not reset when you change insurance or get a replacement.
Pump manufacturers have moved to a model where users can upgrade to new features during the warranty period, though some of those upgrades may carry a cost. Often, the decision to change pumps depends on many factors.
What do I do if my insulin pump breaks or stops working?
Manufacturers are very quick to replace an in-warranty pump that is malfunctioning, but it is important to have an in-warranty pump so you can get a replacement if it breaks. In the event of a malfunction, you will need to transition quickly to injections with the guidance of your care team. Call your health care team right away if a pump stops working.