Feature | April 17, 2007 | Christina A. Staccia, MA,CRC

Tight glycemic control for this growing critical-care patient population necessitates ongoing advances in continuous glucose monitoring devices.

The FDA recently expanded indication for Medtronic's REAL-Time CGM devices, such as the Paradigm system, to include children 7 to 17. Photo courtesy of Medtronic.


Healthcare professionals are under tremendous pressure to provide effective patient care services while striving to increase positive outcomes for all. Recently, much attention has been focused on providing continuous blood glucose monitoring for those critically ill patients with diabetes and other diseases that necessitate frequent objective data.
The number of patients with endocrine disorders that will be hospitalized on a critical care unit is only expected to grow. According to the American Diabetes Association, a person is newly diagnosed with some form of diabetes every 21 seconds in the U.S. The disease has reached a near pandemic level worldwide with nearly 300 million people currently diagnosed with the chronic illness.
The long-term complications of diabetes increase the number of patients who will be hospitalized with life-threatening conditions necessitating immediate corrective surgeries and critical-care intervention. Infected wounds with gangrenous ulcers, coronary heart disease with residual heart attacks and other similar severe diabetes complications are increasing as the diabetic population is growing older.
The Diabetes Control & Complication Trials (DCCT) conducted by the National Institute of Diabetes and Digestive and Kidney Disease (NIDDK) from 1983 to 1993 helped to substantiate the vital role that tight glucose management plays in reducing the short- and long-term complications of diabetes.
The DCCT results had shown that damage to the eyes, kidneys, nerves and heart could be reduced by at least 50 percent with tight glucose control. Additional research has shown that hospital stays and recovery time is much quicker with better outcomes when patients' glucose levels are regulated.
Clinicians and other critical care specialists serving patients with diabetes and similar disorders are now faced with hospital protocols necessitating optimal glucose regulation practices during all phases of treatment. An in-depth review of continuous glucose monitoring equipment and its effectiveness in treating the critically ill patient is in order.
Continuous Glucose Monitoring Devices
There are currently only a few companies with continuous glucose monitoring devices. These devices do not completely replace finger-stick blood glucose measurements. They provide additional information to the finger stick. High or low readings from the device must be confirmed with finger stick before treatment.
MiniMed Paradigm Real-Time Insulin Pump and Continuous Glucose Monitoring System received FDA clearance in 2006, and the company’s CGM devices were just approved in March 2007 for kids 7 to 17. The Paradigm system is made up of the REAL-Time Continuous Glucose Monitoring (CGM) System and the MiniMed Paradigm insulin pump. The CGM can display 288-blood glucose readings a day, which are displayed on the insulin pump. The REAL-Time continuous glucose monitoring kit is sold separately as a cash pay item (not covered by most insurance plans).
CGMS System Gold is used by healthcare providers seeking comprehensive glycemic patterns that cannot otherwise be obtained by traditional finger stick or HbAlC measurements. Clinicians can review the equivalent of 288 glucose readings per day over a 72-hour period of time. This system provides reports that may show dangerous glucose trends exhibited by the critically ill patient in need of a treatment adjustment.
The system contains two key components: a subcutaneous glucose sensor and a small, pager-type monitor. The glucose sensor is inserted into the patient's subcutaneous tissue, commonly in the abdominal area. It's typically worn for a period of 24 to 72 hours while a patient may be in a more critical point of treatment. During this time, the sensor measures glucose levels every 10 seconds.
The battery-operated monitor averages glucose measurements every five minutes, providing 288 glucose readings over a 24-hour period. Glucose data and event information is entered manually by the critical care nurse and is stored in the monitor. Clinicians can download data from the monitor to a personal computer for retrospective analysis.
The CGMS Gold is easy to operate and takes less than 15 minutes to learn how to use by healthcare professionals. The system is also reimbursed by Medicare in all 50 states and has broad private insurance reimbursement.
Dexcom STS System received FDA approval at the end of March 2006. The probe-like STS Sensor is inserted under the skin, held in place by an adhesive. Once inserted, the STS Sensor begins continuously monitoring blood glucose. The STS Transmitter holding the sensor wirelessly transmits the glucose data to a hand-held receiver. The receiver displays the patient's current glucose value. It also shows glucose trends over one hour, three hours and nine hours. The receiver sounds an alarm when a high or low glucose excursion is detected. The device is not waterproof but comes with an adhesive cover for the shower.
Freestyle Navigator is a device with a three-part design. The first is a sensor mount that adheres to the skin (like a patch). It is designed to be worn for several days. The second part is a transmitter that snaps into the sensor mount. The transmitter receives information wirelessly. The third part is a receiver the size of a pager that can be worn on the waist or in a backpack. It receives information from the sensor and transmitter every minute. The receiver displays glucose values, glucose trends and rate of change. The receiver also has high and low glucose alarms.
The Guardian RT System was approved recently by the FDA for people with Type 1 and Type 2 diabetes. This device displays an updated real-time glucose value every five minutes. An alarm goes off when the glucose levels become too high or too low, which helps patients take action before they experience a problem.
Tangible Results
These types of continuous glucose monitoring devices represent the first next steps toward development of a fully automated glucose monitoring and insulin delivery system, namely, an artificial pancreas.
The main advantage of continuous glucose monitoring is that it can help identify fluctuations and trends that would otherwise go unnoticed with standard hemoglobin A1c tests and intermittent finger-stick measurements. It can be useful for identifying nighttime hypoglycemia, comparing glucose patterns before and after starting a specific insulin protocol. It can also be used to educate patients, once they are out of the ICU, about the effects of their eating patterns, activity or effects of insulin regimes on their glucose levels.
The risk of infection and death in the diabetic population is greatly reduced as a result of tighter control of blood glucose before, during and after surgery. Evidence suggests that sickness and death can be reduced among surgical patients with diabetes when tighter glycemic control is maintained. This also helps to reduce the length of stay in the hospital.
Research continues throughout the country on the efficacy and positive outcomes that health professionals can expect while using continuous glucose monitoring devices. Expect to see more information as future improvements develop.

Christina Staccia is program director of A2Z Diabetes Resource Center. She is one of the longest living, healthy infantile-onset diabetics in the world today. She is a Certified Rehabilitation Counselor and author who has lived with diabetes since her diagnosis at the age of one. Staccia is the author of the new book, “Diabetes Living: The Will to be Well.”


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