pump settings, glucose values, carbohydrates consumed, infusion set changes, pump suspends, and more. These data management programs then display data in pie charts, tables, graphs, and percentages above and below target range. The ability to transfer this data and analyze it with the software can help you improve your diabetes care by making it easier to detect trends and patterns that may require attention.
CHAPTER REVIEW
• An insulin pump is a small machine that continuously delivers insulin.
Pumps come in two varieties: durable and patch.
• There are many advantages to insulin pump therapy. The advantages of delivering basal insulin with a pump include multiple basal rates, temporary basal rates, multiple basal patterns, and precise insulin delivery. Boluses can be given to cover food, to correct an elevated glucose level, or both. This gives you flexibility.
• The disadvantages include the risk of DKA, the issues of being attached to a device that reminds you about diabetes and might be visible to others, issues with your skin and with infusion sets, missed boluses because diabetes management becomes more automatic, and cost.
• Pump users should have these qualities: realistic expectations, ability to participate with others in their diabetes care, sufficient diabetes knowledge, willingness to monitor glucose effectively, desire to use an insulin pump, and an understanding of the costs of the device.
• You need to decide which pump to use, and getting properly trained is critical.
SECTION 2: THE NITTY-GRITTY
CHAPTER 3 HOW DOES MY PUMP WORK?
IN THIS CHAPTER
• Uploading and Record Keeping
• Patch Pumps and Pumps in the Future
Although it’s only about the size of a deck of cards, an insulin pump is an impressive, complicated device that contains many components and can perform many different functions. There are two kinds of pumps: durable and patch.
Durable pumps are designed to last many years. They are made of a hard plastic case with buttons, a front screen, a battery compartment with a screw on top, and a space for the reservoir that will be filled with insulin. Clips can be attached to the outer surface so you can place the pump on a belt or waistband. There is a sticker on the pump that has some useful information: the serial number, model and type, company phone numbers, and other general information. At the base of the reservoir shaft is a computer-controlled mechanical plunger that can deliver incredibly small amounts of insulin.
Patch pumps are worn directly on the body. The pod component attaches to the body and has the insulin reservoir and motor inside. It is controlled by a separate controller or personal digital assistant (PDA).
Reservoir
The reservoir comes empty. There is a needle attachment that is used to draw insulin from the insulin vial into the reservoir. The needle is detached once the correct amount of insulin is drawn up; the correct amount depends on how much insulin you use in two or three days. The whole reservoir is screw-turned tightly into the chamber in the pump, and the tubing leads away to the infusion set, which is attached to the body. With a patch pump, the reservoir is contained within the pod, which adheres to the skin.
Screen
The pump has a front screen (the patch pump has the screen on the controller). When not in use, front screens generally display the time (some have the date), insulin remaining, and information about battery life. By pushing different buttons on the face of the pump, you can access different functions in the pump’s software. The software lets you deliver insulin; set or edit basal rates; set or edit the pump calculator; suspend insulin delivery; review your bolus, basal, and alarm histories; and see the exact amount of insulin remaining in the reservoir.
Software
The software not only lets you know the date and time, it also allows your pump to store tons of information, including weeks’ or months’ worth of bolus and alarm histories, blood glucose readings, and basal rates. The software allows the pump to consistently deliver the correct amount of basal insulin. It can also calculate the appropriate amount of insulin needed based on a glucose reading and a carb count entered into the system. Some pumps have a large database of food and carb counts. There are also safety features that prevent the user from providing too much or too little insulin in boluses or for the basal rate. Software also allows you to determine how you want to deliver a bolus every time you deliver one.
Pump History and Downloading
The information stored in the pump can be uploaded to a computer and analyzed by software. Generally the pump connects to the computer using a cable or wireless connection, and once the information is transferred from the pump to a computer, the user can look at graphs, pie charts, lists, and other visual information. Many diabetes care providers download information from the pump during clinic visits, or they may ask you to download it at home and bring a printed copy to your appointment. Between visits, you should look at this information and send it to your diabetes team if you need help troubleshooting some problems.
Blood and Interstitial Glucose Monitoring
Most pumps can connect to a blood glucose meter. In addition, it is possible for some of them to connect wirelessly to a continuous glucose monitor (CGM). This means that the glucose meter and sensor can transmit glucose values directly to the pump’s screen and memory.
Insulin Delivery
Pumps deliver basal and bolus rates of insulin. Basal rates are set by the user, with guidance from the diabetes team. Based on individual dosing, mealtime and correction boluses are given.
Suspend
All pumps have the ability to be suspended so that no insulin (basal or bolus) can be administered. A pump can remain suspended indefinitely but will sound an alarm every so often to remind you that you are not receiving insulin. With most pumps, it is easy to suspend insulin delivery in case you have an emergency.
Alarms
Pumps have alarms. Some are functionally important, such as “low battery” or “no delivery” (called an “occlusion” alarm in some pumps). There are alarms that you can set to remind you to test, take insulin, or check for ketones if your glucose is over a certain amount. If you need to, you can review the last 50 or so alarms. Pumps have different options for the way they notify you, such as various beeps or sounds or with vibration. Most pumps will beep or vibrate when a bolus is complete, when you are currently using a temporary basal rate, or when you have a low reservoir or low battery.
Active Insulin
