… and what exactly happens in the minutes leading to its expiration/deactivation?
This what we tried to figure out today. We had a pod that was shown on our PDM as being activated 3 days ago at 10:01am (9/7/2017). We decided to ride it as long as we could, and test a bolus at the very end of it to see what would happen.
Omnipod says that a pod should be changed 3 days (72 hours) after it has been activated, but that it will remain active another 8 hours after activation, so that you have a total of 80 hours per pod starting at activation.
This is what happened to us:
At 9:58 am we received a pod expiration alert (3 minutes prior to the 72-hour limit, per the PDM 10:01 activation time)
At 4:58 pm ( 1 hour and 3 minutes prior to the 80-hour limit), we received a pod expiration advisory
*at 5:56 pm we started a long bolus (9U)
at 5:57 pm we got a low reservoir alarm (20 U left)
at 5:57 pm the pod expired with the death siren blazing. We were 2.7U into a bolus, which stopped right there.
The open question are:
- What of the 4 missing minutes? Does the countdown start earlier, possibly when you actually fill the pod?
[EDIT] per Eric, it starts counting down when you fill the pod. The PDM, on the other hand, shows you the actual pod activation time.
- Is it always exactly 4 minutes, or does it depend upon another event, such as, for instance, the time at which you filled the pod?
[EDIT] see above: it depends upon when you activated the pod, which is what triggers the 80 hours
you will get very close to 80 hours per pod, but you may not get every minute you think you have: we were short 4 minutes per the PDM records, and got 79 hours and 56 minutes
the pod expiration will interrupt a bolus under way. So, if you start a bolus, be sure to leave plenty of time to complete it before the pod deactivates.
it is possible to know exactly when deactivation will occur, since the 72-hour alarm and the 79-hour alarm show up exactly (a) 7 hours 59 minutes and (b) 59 minutes prior to expiration.