Insulin Pumps

• Insulin pumps replace the need for periodic injections by delivering rapid-acting insulin continuously throughout the day using a catheter.
• They offer many advantages that can simplify diabetes management.
• There are some downsides, but most pump users agree that the benefits are worth it.
• Switching to a pump requires some adjustment, so discuss the options with your health care team before making a decision.

By using an insulin pump, you can match your insulin to your lifestyle rather than adjusting your lifestyle to your body's response to insulin injections. With help from your health care team, insulin pumps can help you keep your blood glucose levels within your target ranges both day and night. People of all ages with type 1 diabetes use insulin pumps, and people with type 2 diabetes have started to use them as well.

How do insulin pumps work?

Insulin pumps deliver rapid- or short-acting insulin 24 hours a day through a catheter placed under the skin. They deliver insulin in the following doses:

• Basal doses
  Basal insulin is delivered continuously over 24 hours and keeps your blood glucose levels in range between meals and overnight. Often, you program different amounts of insulin at different times of the day and night.
• Bolus doses
  When you eat, you use buttons on the insulin pump to give additional insulin called a bolus. You take a bolus to cover the carbohydrate in each meal or snack. If you eat more than you planned, you can simply program a larger bolus of insulin to cover it.
• Correction or supplemental doses
  You also take a bolus to treat high blood glucose levels. If you have high blood glucose levels before you eat, you give a correction or supplemental bolus of insulin to bring it back to your target range.

Where do I keep it?

Knowing how an insulin pump works is one thing, but you may be wondering where you are supposed to put it. You can attach the pump itself, or a special carrying case, to your waistband, pocket, bra, garter belt, sock, or underwear. You can also tuck any excess tubing into the waistband of your underwear or pants.

When you sleep, you can try laying the pump next to you on the bed. You can even try wearing it on a waistband, armband, or legband, or clip it to your blanket, sheet, pajamas, stuffed toy, or pillow with a belt clip.

Showering and bathing require other methods because, although insulin pumps are water resistant, they should not be set directly in the water. All insulin pumps have a disconnect port for activities, such as swimming, bathing, or showering, so you can simply disconnect it. Some pumps can be placed on the side of the tub, in a shower caddy, or in a soap tray. There are also special cases you can buy to hand them from your neck or from a shower curtain hook.

Won't it get in the way?

It is still possible to have fun while using an insulin pump. When you exercise or play sports, you can wear a strong elastic waistband or armband with a pump case. Women can tape the insulin pump to the front of their sports bra. Some coaches do not allow any devices to be worn because getting the pump knocked into you or falling on it can be painful. In this case, you may just need to take the insulin pump off.

What happens when I take it off?

When you disconnect your pump, you are stopping all delivery (basal and bolus) by the pump. Here are some important tips to remember when disconnecting your pump.

• If you stop your pump during bolus delivery, it will not be resumed. You may need to program a new one.
• Be sure to bolus to cover the basal rate you will miss. If your blood glucose level is under 150, you can wait an hour to bolus.
• Do not go longer than 1 to 2 hours without any insulin.
• Monitor your blood glucose every 3 to 4 hours.

What are the pluses and minuses?

Now that you know how the insulin pump works and how to wear it, take a look at some of the pluses and minues to see if you think it's right for you:

Advantages of using an insulin pump

• Eliminates individual insulin injections.
• Delivers insulin more accurately than injections.
• Often improves A1C.
• Results in fewer large swings in your blood glucose levels.
• Allows more flexibility with what and when you eat.
• Reduces severe low blood glucose episodes.
• Eliminates unpredictable effects of intermediate- or long-acting insulin.
• Allows you to exercise without having to eat large amounts of carbohydrates.
• Simplifies diabetes management by giving you access to insulin at the push of a button.
• May improve your quality of life.

Disadvantages of using an insulin pump

• Can cause weight gain
• Can cause diabetic ketoacidosis (DKA) if your catheter comes out and you don't get insulin for hours.
• Can be expensive.
• Can be bothersome since you are attached to the pump most of the time.
• Can require a hospital stay or maybe a full day in the outpatient center to be trained.

Despite these issues, most pump users agree the advantages outweigh the disadvantages.

How do I get started?

Once you have talked with your health care team and have become comfortable with all of the options on your insulin pump, you and your team will need to do the following to get you started:

1. Determine how much insulin to use in the pump by averaging the total units of insulin you use per day for several days. (You may start with about 20% less if you are switching to rapid-acting insulin.)
2. Divide the total dosage into 40-50% for basal and 50-60% for bolus insulin.
3. Divide the basal portion by 24 to determine a beginning hourly basal rate.
4. Then, adjust the hourly basal rate up or down for patterns of highs and lows, such as more insulin for dawn phenomenon and less for daily activity.
5. Determine a beginning carbohydrate dose (insulin-to-carb ratio) using the 450 (or 500) rule. Divide by the total units of insulin/day to get the number of grams of carbohydrate covered by one unit of insulin. This dose may be raised or lowered based on your history and how much fast-acting insulin you took in the past.
6. Determine the dose of insulin to correct high blood glucose with the 1800 (or 1500) rule. Divide 1800 by the total units of insulin/day to see how much one unit of insulin lowers your blood glucose. This dose must be evaluated by your health care team. It is often too high for children or for people who have not had diabetes very long.

Tips for adjusting to a pump

It may take several months to get comfortable with the pump. During those first months is the time to adopt some good habits. Here are some tips to help you adjust:

• Take your insulin at a specific time, such as five minutes before you eat, so you don't forget boluses.
• When traveling anywhere, bring extra supplies or at least an insulin pen, in case you are unable to use your pump for some reason.
• A pump allows you more freedom to eat what you want when you want. So you can eat more carbohydrates and still manage your blood glucose, but this can lead to weight gain. Talk to a dietitian about how to keep a balanced diet. It's a lot easier to maintain weight than to lose it.
• When you take the insulin pump off or turn it off, figure out a system to remember to turn it back on. Listen to the alarms on the pump or set a timer!
• Make a habit of recording blood glucose checks, carbohydrate amounts, carbohydrate doses, correction doses, and exercise when you do them. It really helps to sit down and look over your blood glucose record at the end of every week (or even every day) to see if you have any problem areas. Reviewing your records is the key to improving blood glucose control.
• Use record forms from your health care provider or pump manufacturer, or make your own. Just be sure that you have enough room to record everything you need. Keeping daily records is best, but some people find keeping records for two weekdays and one weekend day gives enough information to see the patterns.

Fortunately, you don't need to become an expert on insulin pumps overnight. If you are uncertain about anything, ask your health care team for help. Everyone learns at a different pace and it's OK if it takes you a while to get the hang of it.

The ADA also has resources to help you. Get more information about insulin pumps on page RG24 of the 2008 Resource Guide.