Detecting Infusion Failure

What are the early signs of infusion failure? I had a failure last week that took almost a day to figure out from elevated BGs. When I pulled the MM Quickset (6mm), it was bent in two spots. I’m not sure if it was an insertion problem or maybe pump clip slipping off my belt pulled the cannula part of way out. Skin was wet with insulin under the adhesive, but nothing on the outside. Are there any earlier typical indicators?

I’m using the same infusion set (9mm cannula though). Unexplained blood glucose numbers increasing is certainly one sign of issues with your site. Another would be that insulin smell - touching my site with my fingers, I don’t detect it but if yours was leaking insulin to the surface, you probably would.

If you happen to be using a CGM (Dexcom or other), you’ll notice the trend a lot sooner (increased frequency of blood testing is a pain in more ways than one).

At the opposite end of the spectrum are your pump’s NO DELIVERY warnings - that indicate either a problem with the reservoir, tubing or site itself - some sort of blockage. Since your case involved a good delivery of insulin, just not to the right place, it doesn’t apply.


Pain, when my site hurts after 1 hour, it gets pulled. Hurt is the first thing I usually notice.


Any time I have elevated BGs that I can’t explain, and that continue to rise or hold steady for more than a couple of hours, I do a correction or the next meal bolus with an injection. If that brings me down, I know it’s a site problem.

I also find that if it’s high with no reason, I use an injection to correct. If it comes down, I know it’s the infusion set. So if one or two corrections on the pump don’t work, injection and pull the old one out and put new one in. And I will put a side note here, since losing some weight, I had more than my fair share of kinked infusion sets. Made the change to metal a few years ago and have not had any problems since going metal.

I can usually taste/feel if its high (although, that wasn’t true this morning). My Omnipod pump sounds out an audible alarm. But, I remember that detecting a hardware failure was a huge problem for me on a MM. I could never be totally sure if it was a hardware problem or just me. Since it took 4 hours to see if the correction even worked, I was generally looking at 8 hours until I could say, for sure. Are you wearing your CGM?

Yes. Continuously except for changes/warm ups, failed calibrations and other CGM problems.

It’s different for everyone I think, but for me, the very first indicator that an infusion site will fail is pain right when I’m inserting. I use the Sure-T’s with the metal canula, which does not have an injector. I place it manually. If it hurts when I insert, chances are that it’s going to fail. Not entirely sure why that is, but if it’s painful, I know to keep an eye on my count all the time while it’s in. Second, is the sugars. For some reason when I get an alert from my pump that I have “No Delivery” all of the sudden, it means I haven’t been getting delivery for a while, and if I haven’t been checking my sugar often enough, I won’t catch it until my pump alarms. By then, I’m usually pretty high.

If you’re having a lot of issues, you might want to consider changing your infusion sets. See if you can get ones with a metal canula that won’t bend. Or just try any different kind from the one you have. Not all infusion sets work for everyone.