The Insulin Pump: Is It Right for You?
For years as a type 1 diabetic, I have been watching the news about insulin pumps. I have watched my son's friend have one implanted when they were both in medical school and watched the past president of our American Diabetes Association board have a healthy baby after she had one implanted. She came through the pregnancy well, and her son is a joy.
I read about the pump because I take my blood glucose level many times a day and take multiple injections a day to keep my diabetes under control. I figure if this is an option that I have thought about, you probably have, too. So for all of us, here is an article about this treatment alternative.
When you research the people who do best with the pump, what is evident is that to do well one has to be very motivated to control his or her diabetes as it means assuming substantial responsibility for day-to-day care. A person must be able to understand and demonstrate the use of the pump, self-monitoring of blood glucose levels, and the use of the data so obtained.
What the pump can give you is flexibility, particularly in meal times and travel. So let's look at the pump so that you can make an informed decision if this is right for you.
Insulin Pump Basics
An insulin pump method provides a continuous subcutaneous insulin infusion (CSII), meaning that insulin is constantly injected under the skin. It is seen as an alternative to multiple daily injections for people with type 1 diabetes who are highly motivated, for those with very busy lives, or for those who can not control their diabetes with 2 or 3 injections a day.
The components of the system consist of a pump and an infusion set. The pump unit contains a small syringe reservoir filled with short-acting insulin, an electromechanical assembly that advances the syringe plunger, and a microprocessor.
The infusion set, along with the pump unit, consists of a plastic tubing joined to a needle or plastic cannula that is inserted under the skin and secured with tape or an occlusive dressing.
Insulin pumps are the size of a credit card and as thick as about 15 of those cards. It is carried in a pocket, on a belt, or tucked into clothing or underwear. Sounds good, huh? But here is the rub. These pumps do not yet modify insulin doses to maintain proper blood glucose levels, nor do they automatically give doses when needed.
The person with a pump adjusts the amount of insulin they receive by regulating their pump settings based on data from frequent self-monitoring of blood glucose levels.
Insulin Pump Benefits
What are the special features of the pump that we can't do easily without the pump? It has the capacity of providing insulin both at slow continuous basal rate, which stimulates postabsorptive insulin secretion, and in boluses, which mimic normal peaks of insulin released after a meal.
These doses are variable over a wide range of time and doses. Changes in basal rate may be programmed ahead of time to counter predictable blood glucose level variations, for example, if one has early morning high blood glucose levels.
In terms of control, research shows that the pump is more effective than 2 injections a day and comparable in efficacy to 4 injections daily.
Insulin Pump Challenges
So why don't we all have an insulin pump by now? Well, for one thing the pump can't read blood glucose levels and then adjust insulin doses. That means it is not an artificial pancreas, which is what many of us are waiting for.
Another problem is unpredictable variability in absorption from subcutaneous injection sites. These features make it difficult to approach a normal metabolic state. Individualized target values for blood glucose are necessary for each person with a pump and therefore frequent self-monitoring becomes part of the program.
Insulin Pump Guidelines and Tips
There are some guidelines that must be addressed before using a pump. First, you as the diabetic, must be willing and able to monitor your blood glucose at least 4 times a day. For those of us on multiple injections a day, this is no problem.
For those of you taking 2 injections a day, you may want to think about this aspect of the pump. Those of us who follow our diet carefully are also more likely to succeed on the pump for all of the reasons that they do well with multiple injections.
Second, blood glucose values need to be selected to ward off hypoglycemic events. Why state that here? The pump itself does not raise the number of these events; however, as we try to keep our blood glucose in the old normal range and we intensify treatment, we may increase the risk of serious hypoglycemia. This is especially true for people who do not experience symptoms before hypoglycemia occurs.
Skin care is very important with the pump as you may get more infections at infusion sites. People with a history of repeated staphylococcal skin infections or who are nasal carriers may be at higher risks for these infections.
Plugging of infusion sets and leaks in infusion-set connections are common in this type of therapy. These problems can be corrected with a correction of the system that you can learn, but if you don't know your insulin delivery has been interrupted, you can develop ketoacidosis.
This is a system, as you have seen, that requires effort, perhaps more effort than using injections to control diabetes. The plus side to using the pump is an increased sense of well being; however, those under extreme stress or those with emotional problems may have difficulty with the program.
This is said so that you think more than twice about the program and so that you look at yourself honestly before looking into the pump more carefully.
Here are some guidelines that physicians use to get a patient started.
- First, the diabetic must be an "expert" on caring for his or her diabetes in the conventional manner.
- Once the pump is implanted, the diabetic should have a 2 to 3 day period of training, if this is outpatient. A friend or relative who knows about diabetes should be with the new pump user because of the risk of hypoglycemic events. No unusual activities should be started until the appropriate insulin doses have been established.
- Before using the pump, the user should practice loading and programming the pump and changing infusion sets. The infusion set is secured with an occlusive dressing or paper tape and is changed every 2 to 3 days to avoid irritation.
- The target ranges need to be set. These will be higher for those with a history of hypoglycemic events, and lower (not exceeding 100mg/dl) for pregnant women. Generally, they will be between 80 and 140 mg/dl before meals and at bedtime.
- Initial doses with the pump are set. The basal rate is usually set at 50% of the total prepump dose. Pre-meal doses are started and these are changed 10% to 20% every 1 or 2 days to move toward target values.
- Finally, decisions as to the type of short-acting insulin are monitored (eg, regular or lispro depending on blood glucose levels before meals and prebreakfast readings will determine changes in basal doses).
Is an Insulin Pump Right for You?
OK, we have given you the real skinny on the pump and perhaps you're saying "why?"
Well, here are some reasons. Approximately 90% of persons who change to the pump achieve improvement in diabetes control. If you believe the results of the DCCT, you will know the benefits of this last sentence.
Add to that 50% of those who go on the pump achieve at least temporary normal glycated hemoglobin concentration, and 15% are able to maintain normal yearly averages for at least 3 years. Most people who use the pump appreciate the greater flexibility in terms of matching insulin doses to variations in diet and exercise.
It would appear that pump therapy is as safe as multiple-injection therapy when recommended procedures are followed.
Once again, we can go over the complications. These include infections at infusion sites, which occur in about 30% of users. Ketoacidosis can occur if there is an undetected obstruction of the infusion tubing, and finally, more hypoglycemic events as with any intensified therapy may occur, as the person tries to gain closer control of diabetes.
Finally, let me tell you the results of a very unscientific survey that I did with only people from my city and only people I know who have a pump.
There was not one of these fine people who would go back to pre-pump days. One showed me her son and said, "See why I love the pump."
Another who is a doctor said, "It makes emergencies less of a problem for the doctor," and for others, the answers were more of the same. Each of these people is highly motivated. They would be excellent with a multiple injection program. They are educated about diabetes and want to live the fullest of lives.
If you think you are a candidate, do talk to your specialist about the pros and cons for you. Read the literature from the makers and ask to speak to people who have the pump. They really know what life is like on and off the pump.