Tag Archives: constant glucose monitoring

Minimed Constant Glucose Monitor

Happy New Year! As promised a follow up to my earlier post in which I detailed my changeover to an insulin pump with constant glucose monitoring. As described on December 12, I’ve been using the Minimed Paradigm 522 with the Guardian constant glucose sensor.

If you’re completely bored by this and follow my articles of travel, restaurants, clubs, and Denver life – you should skip this and read my story on American Airlines flight 1469. However as insurance starts to cover this equipment more type 1 diabetics will be utilizing this and similar monitors – so hopefully this will help those new to this.

In brief: Pager size insulin pumps are used by type 1 diabetics in lieu of injections. Pumps better mimic the pancreas by giving a constant dose of insulin with manual doses at meals or as needed. An ancillary gadget called a “constant glucose sensor” sends your current blood sugar reading to your pump, providing you with a constant stream of blood sugar numbers and direction of blood sugar level – rather than the lone number obtained from a finger prick.

Overall it’s an incredible life changing tool for a type 1 diabetic. Knowing the TREND of your glucose is something that was only in the realm of imagination for years. Now, to be aware and know your blood sugar minute by minute, WITHOUT the need for (as many) messy finger pricks is an enormous step forward. And to have to blood glucose number sent directly to a small screen is a wonder of med-techy synergy.

Here are the drawbacks. Well not exactly drawbacks, but things to be aware of in order to develop your own workarounds and methods to match your daily life.

Appearance: The sensor and transmitter piece aren’t quite as sexy looking as the photos. It’s necessary to cover them with a small dressing. No big deal – the starter kit includes transparent adhesives. Medtronic sells a pack of 100 at the astronomical price of $62, but you can find similar at Walgreens for under $5.
New Sensor Obligation: When starting a new sensor you need to allot yourself a seven hour block of “awareness time.” Better said: keep your meter handy.

After starting a new sensor you’re required to enter your first BG in two hours, then another in five hours. It’s not practical to start a new sensor late in the evening, as you’ll be alerted to enter a BG in the middle of the night. After the two and five hour BG calibrations you’ll be prompted for one BG entry (calibration) every 12 hours. This is pretty easy, and I’m getting used to “thinking 12 hours ahead.” For example if I do a calibration at 2pm, I have to remember to do one around 10pm or before bed so my pump doesn’t wake me up at 2AM requesting a calibration. Typically morning and early evening is best, (before meals,) as your BG needs to be relatively stable for the best calibrations. You can set your calibration reminders up to four hours before a necessary BG entry. But again think 12 hours ahead. If you’re planning to sleep in Saturday morning you don’t want your last Friday entry to be 6pm, or you’ll be harassed by your pump at 6am. This hasn’t been an issue so far as I’ve actually been taking MORE manual readings to test the accuracy.

Accuracy and Rapid Changes: During periods of rapid change the CGM definitely lags. If my BG is 200 and I lower it down to 100, my spot checks show it will be a bit slower to reach 100. BUT, I do show during normal periods of minor fluctuation it’s very accurate. Its stable periods (non-rapid change) it’s been leveling out matching my finger sticks within 20 points.

However I am bit disappointed in how it matches blood sugars that are rapidly rising. And I’ve found when my level is LOW and bring it up, the readings bottom out and take quite a while to reach up to where it should be. These “flat periods” and annoyances are similar to blogger Jay’s experience in this recent post. I see way too many of these stagnant periods when I KNOW my levels are changing, but the results are slow to follow and stagnate within 10 points.

Attempting to remedy this I’m experimenting with new sensor sites. I realized my last sensor was on a site where I’ve given myself many shots over the years. I’m on day two of a new sensor, placed on my upper leg, and am watching the results closely. Pasta dinner at Maggiano’s last night DID prove more accurate, although my manual checks showed little fluctuation anyway.

Continue reading Minimed Constant Glucose Monitor