An insulin pump is a small, battery-powered microcomputer. It looks like a pager and is usually worn in a pocket, or clipped to a belt or waistband. The pump holds a syringe filled with rapid-acting insulin (Humalog™ or NovoRapid™). The syringe is attached to an infusion set, which is a thin plastic tubing with a small needle at the end. The needle is inserted into the fatty tissue below the skin, and then removed. This leaves a tiny, flexible plastic tube in place which must be changed every two to three days. The pump is programmed to deliver insulin continuously through this tube. A small dressing holds the infusion set in place.
If you have discussed the option of an insulin pump with your diabetes specialist, you may be starting the search for the right pump. You, too, may be looking for greater flexibility in managing your diabetes. If so, you are likely asking yourself some questions. Which of the four pumps available in Canada should you buy? Which pump has the features you need and want?
Do your research. An insulin pump is a major investment that you will use constantly for the next few years. Think about similarities and differences between pumps, and what to consider in deciding.
Pumps differ in how basic features appear and in the bells and whistles they offer.
The Animas pump’s reservoir holds 180 units. It can program the smallest basal rate increment (0.025 unit/hour). The screen offers a contrast of yellow print against a dark background, making it easy to read, except in the sun. It is rated as waterproof to a depth of eight feet for half an hour, but some tests show 12 feet for up to 24 hours. It does not currently communicate with a blood glucose monitor.
The Cozmo pump holds 300 units. It comes with a thin glucose monitor that attaches to the back of the pump and communicates with it. You do not have to carry a separate monitor, but must still carry strips and a lancing device. The Cozmo pump has an IPX8 rating – waterproof to a depth of eight feet for 30 minutes. It also has added ‘alert’ features that reminds you when it is time to change your infusion set or if you have missed your meal bolus.
This pump holds 315 units. Basal increments are set in 0.1 units. The type size on the pump screen is quite large, making it easy to read. The display orientation can be flipped 180 degrees to help view it from any angle. It is waterproof for up to one hour at eight feet.
The pump comes with a second back-up pump that will run up to six months. It can be used in case the main pump fails. (Other pump companies replace a failed pump quickly.) The second pump can be handy when travelling far from home. However, other pump companies offer a travel loaner pump at little or no cost. Ask about this if you like to travel.
The Accu-Chek pump will work for 2200 days (six years), then must be replaced with a new version. Check on what would happen if the pump were to fail after four years, but before six years are up. Get any agreement in writing with a signature.
Another unique feature of this pump is the pocket device, somewhat like a palm pilot, that comes with the system. The device stores information, such as insulin to carbohydrate ratios, correction factors, and carbohydrate lists so that you can calculate boluses. It includes an Accu-Chek meter that sends blood glucose readings to the pocket device. However, the device does not communicate with the pump. If you lose the handheld device, the pump does not have a built-in calculator like other pump models.
The 522 and 722 models differ only in reservoir size. The 522 model holds 180 units, while the 722 model holds 300 units.
Unique to the 522/722 pump is the ability to communicate with another separately purchased device called a continuous glucose monitor. This allows you to check glucose level readings continuously through a sensor inserted under the skin. The sensor is attached to a transmitter about the size of a quarter. Glucose readings are sent wirelessly to the pump every five minutes and can be viewed on the pump screen. However, treatment of high or low readings must be based on finger poke tests. The sensor readings may not match these tests, as the sensor does not sit in blood but in a body fluid called interstitial fluid. Information about trends and the direction your blood glucose is moving (high or low) can be used to adjust your insulin. The sensor requires calibration with finger poke tests, twice daily. The sensors are also purchased separately and changed every three to six days. Some insurance plans do not cover this cost. To save on costs, the sensor can be worn only periodically. It is possible that a similar feature may be offered with other pumps in the near future.
Medtronic also sells other pumps (models 515/715) which are the same as the 522/722, but not capable of communicating with the continuous blood glucose monitoring system.
Animas: www.animas.ca and animascorp.com
Contact information: www.autocontrol.com/contact.html (In Canada, Cozmo is distributed through AutoControl Medical.)
Disetronic/Roche: Accu-Chek Spirit pump: www.disetronic-ca.com
(click ‘contact us’)
Medtronic Minimed Paradigm pumps:
www.minimed.com and www.minimed.ca
Contact information: www.minimed.ca/ContactUs.shtmlx
General pump information:
Each pump company offers a web site. This is a good place to start your research (see resource list above). A good comparison chart of insulin pumps can be found at www.diabetesnet.com (type ‘compare insulin pumps’ into the info box). If you access this site, remember that only the four pumps discussed in this article are available in Canada.
Call your local diabetes education centre or endocrinologist’s office to learn if they offer information classes or materials on pumps. They can advise on which reservoir size and basal/bolus increments would work best for you. As well, they can give you contact information for local pump company representatives. Take the time to meet representatives to get hands-on exposure to the pumps. Some offer group information classes and others meet with you one on one.
Shopping for an insulin pump is both exciting and overwhelming. Choices, choices! No matter what you decide, be assured that each pump is a good product. However, the homework pays off when you choose a pump that suits your needs and lifestyle. Research is key! Make an informed decision about this important long-term commitment. The right choice will make using the pump even more rewarding for you.