The “guidelines” say you should do it in the morning, with the logic being if there is a problem with it, you will know right away (well, within a few tests) rather than sleeping for 8 hours to wake up in DKA.
For some reason, I have a terrible time after changing my infusion sets. If I change in the morning (during which my BG’s are touchy, even without a set change), my blood sugar skyrockets, and takes me about two days to get things back under control. Another day later and it’s time for a set change again!
There is a lot of theories on this topic. Some arguing that the insulin “pools” at the new site, and takes some time to absorb. Others think it is due to some type of reaction from your body to the trauma of the needle and cannula. I’ve heard some people concerned about the little drip of insulin that may leak out when you pull out the old set (so they will leave the old one in for a few hours, but disconnected from the pump).
I’ve found what works best for me is to change my set at night, sometime after dinner. Seems like it “behaves” a little better when I give it some time to acclimate overnight without any boluses. Even still, the first meal I bolus for (which is usually breakfast, a good 6-8 hours after changing) still runs high at my post meal test.
I’ve even experimented with delivering a bolus after changing sets, in addition to the bolus that fills the cannula. I’ll pump in another 5 units or so, and it seems to have no impact on my readings at all. However, if I deliver more than that, say 7-10 units, it will drop my readings (although still not as much as it should).
Anyone else out there experience this? Have you found anything that works for you?