I think you might be thinking of New Dose Wonkiness (NDW)..when you increase the dose and instead of the numbers going down, they go up
When a cat isnt regulated, the blood glucose has probably been high for a while. As the insulin starts to take effect and numbers start to come down, the liver has to learn to adjust to the lower numbers. We call this "liver training school". But before it relearns that low numbers are ok, when the BG drops to a number lower than the liver is accustomed, or if BGs drop low, or if the BG drops suddenly, the liver”panics” and reacts by releasing counterregulatory hormones and glucagon. This drives the BG back up. This is what we call a "bounce". Bounces can take up to 72 hours to clear so we are generally careful about increasing doses during the bounce. Once the bounce clears, then you can see the "real" numbers and determine if the dose needs to go up or down.
There are a couple of things that can trigger bounces.
A level less than the cat is used to (can be any number, not necessarily under 50)
Fast dropping numbers (like 50 points an hour)
Does that help?