I inserted a new glucose sensor today and as soon as I pulled the needle out, it began to gush up through the site and all over the place. I put pressure on it for about 10 minutes and managed to stop the bleeding, and because it says some bleeding is to be expected sometimes, I attached the sensor and went on my way. Well about 7 hours later, I checked it again and it must have started bleeding again because it went through the adhesive tape and all over my shirt. In addition, I had been getting wildly inaccurate readings throughout the day (i.e. pump flipping out that I was 45 and dropping when a meter says I’m at 135.) which made me suspect that some blood had congealed inside the sensor tube and it wasn’t getting fresh fluid.
So I guess my question is, how much blood is too much? I’m afraid to waste the sensors, but if I can’t stop the bleeding/it doesn’t become more accurate after numerous calibrations, I should pull it and put in a new one, right? Other than pressing on it, is there any other way to prevent/slow bleeding?
Unrelated to diabetes, but all my facebook friends are tech-saavy enough to find their own way, so I figured I’d offer to you guys on TuD – private message me your email if you would like an invite to Google+. 
I usually try to wait and see if the sensor values improve. Like you I don’t like to waste especially the sensors. I really try to resist the urge to calibrate too frequently as I think it only makes things worse. The Dexcom seems to be more forgiving in that arena. Usually if I just leave it alone it slowly gets closer and closer at which point I calibrate. I find one that starts out that way never really does that great though. As far as the bleeding I would suggest an ice pack to the area. The cold makes the blood vessels constrict which usually stops the bleeding (although not sure how it will effect the sensor readings). I guess if it is bleeding all over your shirts you have to start comparing the money for the sensor vs the money to replace shirts. Good luck!
I can’t help you with the blood question, but it will definitely make your CGM readings go wacky. The interstitial fluid only has a percentage of glucose in it, which is relative to the glucose in the blood (the calibration helps determine this percentage). If you calibrate with a lot of blood in the area (meaning that ratio of interstitial-fluid-glucose-to-blood-glucose is high), then the blood moves away from the sensor site, it’ll think you’ve just dropped dramatically.
Sometimes if I have a really bad calibration (i.e. I’m forced to METER BG NOW when my sugar isn’t stable), I’ll selet “NEW SENSOR” rather than “CALIBRATE”. This will wipe out all of the previous (bad) calibration info and start from the current reading. I’m referring to the Medtronic pump/CGM. But I’ve had some bad luck with my CGM over the past couple of days. See my recent blog post…
TDC: Google+ is Google’s new social networking site that’s supposed to be a better alternative to Facebook in terms of controlling the privacy of what you share online and organizing your friends into different groups based on the types of things you want to share (i.e. put your bosses in a separate “circle” if you wanna post an inappropriate joke, etc). It’s not entirely open yet, somebody who is already a member has to invite you to join.
Scott: I’ve only had a really bad time with it lately with this bad site. It must have gone right into a vessel because it bled for hours despite pressure, continued to bleed after I pulled it out, and there’s a huge bruise there now. I figured that it was something like your explanation, as my initial assumption was that some of the blood had clotted inside of the sensor tube making it unable to access any fresh fluid.
MossDog: My pump educator said that as you calibrate spread out over a few days, it’s designed to become more accurate over time i.e. more accurate readings on day 3 than on day 1. Of course, that’s for the Minimed and I don’t know a whole lot about the Dexcom… Thanks for the ice pack tip, I’ll definitely try that next time because I don’t want anymore of my favorite shirts being ruined by surprise gushers.
