What Nurses Need to Know About Continuous Glucose Monitoring

Case 1. A 27-year-old man has had type 1 diabetes for 19 years. His hemoglobin A_Ic level prior to starting RT-CGM

[real-time continuous glucose monitoring] was 9.4%. . . . Over the 15 months of RT-CGM use, he was able to decrease his hemoglobin A_Ic level to 7.7% and maintain it at that level for several months. After he stopped using RT-CGM because his insurance didn’t cover sensors, his hemoglobin A_Ic level rose to 8.5%. When he got a new job and was able to resume use of RT-CGM, after three months his hemoglobin A_Ic level had once again decreased, this time to 7.9%.

Case 2. A 10-year-old girl has had type 1 diabetes for almost three years. Her hemoglobin A_Ic level before starting RT-CGM was 9.8%. By five months after starting RT-CGM her hemoglobin A_Ic level had decreased to 7.2%. After discontinuing sensor use because of the high cost of RT-CGM supplies and a lack of insurance coverage, her hemoglobin A_Ic level rose to 8.2%.

The above are composite cases of patients with type 1 diabetes who used real-time continuous glucose monitoring devices as a tool to improve their blood sugar control. They’re from an article in the April issue of AJN that gives a balanced overview of this technology, including how it works, its current uses (as a diagnostic tool, a warning system for hypo- and hyperglycemia, and a way to improve long-term glycemic control), its coverage and costs—and its advantages and disadvantages, as described here:

The advantages of using a sensor include

* the availability of glucose values every few minutes.

* a possible reduction in the frequency of hypo- and hyperglycemia.

* tighter glycemic control and a possible decrease in long-term complications.

* a possible reduction in the frequency of finger-sticks.

The challenges to using a sensor are that

* it requires its own insertion site in the body, and the receiver must be within five to 10 feet of the transmitter, depending on the product, for glucose values to be detected.

* it often requires the patient to carry the receiver around, in addition to the other supplies. (Medtronic currently has a product on the market that’s both an insulin pump and CGM receiver in one unit, and Abbott’s CGM receiver also functions as a glucose meter. Other companies are also working on creating integrated products that deliver insulin and measure glucose values. Currently, two insertion sites, one for the insulin pump and one for the RT-CGM sensor electrode, are needed in the sensor-enhanced pump. Several companies are at work on combining insulin delivery and glucose measurement at a single injection site.)

* patients may need to actually do more frequent glucose testing.

* some patients will have difficulty understanding the difference between finger-stick glucose values and sensor values. There is a learning curve here

This technology is right for some, not so right for others. Nurses caring for people with diabetes will need to know more about it as it becomes more common.

Patients who decide to use RT-CGM devices may initially face frustration while getting used to the system, especially when adjusting to the differences that can occur in either direction between blood glucose and sensor values. Many will need encouragement from nurses. It’s nurses’ responsibility to give their patients the most updated information about the advantages and disadvantages of new tools that may help them better manage their diabetes.

We hope you’ll read the article, and let us know your experiences with continuous glucose monitoring, either as patients or nurses…or both.