How can you tell your insulin may have lost its power?

OK, a while back we had a discussion about site problems. Over the course of this weekend, I changed sites (yesterday morning) hoping that the change would help me get my numbers down (I had been dealing with 160-230 values for most of Saturday, in spite of not having eaten that many carbs).

Truth is numbers yesterday (and this morning) kept being high (my most recent one was 170, a few minutes ago).

Question is: could it be the insulin? I am starting to suspect it is. How do you judge a defective vial?

I know that the Humalog website recommends not letting insulin get above 86 degrees F. I wonder though, depending on where the pump is worn, if body heat or the temp. in the air (especially in summer) can affect the freshness of the insulin? I notice Noah’s BG creeping upward on day 2 sometimes and wonder about this as well.

I recently had a similar issue, where right after changing a site, my daughter’s numbers kept climbing up. By noon they got to ~300 despite a few boluses, I thought it might be a bad site, so I went ahead and changed the site again. Within a few hours her number didn’t go down and it looked like they kept going up.
That’s when I realized that I started a new bottle of insulin that morning, so I kept the site, but refilled her reservoir with another batch of insulin and with in an hour or so she was back to normal.
So, as far as I can tell, there was no visual indicator of “bad” insulin, it is a waiting game for me…

I know what you mean- a visual like going cloudy or changing color would be so helpful. I used to write the date on the vial when I opened it, but now we go through them too fast to worry about that.

I like the idea of refilling the reservoir. Let me confirm what would be required for this:

  1. Unplug.
  2. Take out the old reservoir.
  3. Rewind.
  4. Refill as you would normally.
  5. Prime but not through the needle? I’ve never done that… the little drops come out of the hole on the side of the ring that leads to the infusion set?
  6. After that, you do a fixed prime as well?

I’ve only had it go bad (i.e. lose effectiveness) due to time or heat. The insulin manufacturers say the 28 day clock begins once it comes to room temperature. So when it gets old, it just loses effectiveness. Sometimes if I can’t get my numbers down and I’m running high no matter what, I’ll change out the insulin and that fixes it. I’ve noticed that sometimes I have a harder time with Novolog from a 3-3.5 week old vial in my pump than I would have on injections. They don’t usually last that long, though.

The other time I had it go bad was when my purse was sitting under the heat vent in the car on a car trip.

Hmmm. If I definitively rule out other things, I simply try a new bottle. Do you use Novolog or Humolog? Apparently, people have noticed that the Humalog isn’t as stable…So often, though, it turns out something “sick” is sneaking up on me and my blood sugar registers it before my brain does. This actually happened to me a couple of weeks ago. I did the insulin exchange, but with no effect. It took several days before I realized what was going on. Body temp can destabilize the insulin most definitely. When I was waiting tables in grad school, I kept my insulin in my apron. Even though it was in an insulated pouch, it got too hot. I wasted a couple of bottles before the clue phone rang. Also, if you’re sustaining high for a couple of days, you may become a bit insulin-resistant in which case it takes more than your regular ISF to get it down.

I always think that somethign could be up with my infusion set or the site…even if i change it all out…when i run high for no good reason, i generally take a shot with the correction amount and sometimes add in my basal rate for an hour - (of course if you add your basal rate in, then suspend your pump for an hour) - then in 2 hours check my BS to see if it has any affect.

although i am an avid pumper, i have no problem taking a shot - sometimes i need to be absolutely certain that i am getting the insulin. When swimming for the day, i take my basal for one hour via pump - then if an hour passes, i will take my next hours basal in a shot. For me this easier than disconnecting 'water cover inset"(dont know what to call that) - and reconnecting the pump for .5 units of insulin - plus the infusion sets i use disconnect right at the site, which i wear on my hip and can be a little too much skin showing to reconnect. --anyway i know this part isnt necessarily related…but i have told others about my swimming plan and they seemed to like it.

If Aidan’s insulin is nearing 30 days old, I change that. His sites rarely go “bad,” unless they are nearing 2 days on tummy, or 3 days on rear end.

if after i have changed my infusion set and my site, and nothing happens, i throw the vial of insulin out and start again. this has made my life much easier. no more guessing games to deal with. for the most part (85%), this usually works. even if the experation date on the vial seems like it should be ok, sometimes its not. hope this helps. give it a try.