Hi Bobbie,
I don't usually post in PZI because I have so little personal experience with PZI or Prozinc compared to Lantus and Levemir, but your post title caught my eye. I hope you don't mind if I leave some non-insulin-specific thoughts here. I enjoy seeing people who want to think things through so maybe something I say can help.
When I'm studying someone's spreadsheet, I look at the past for history and perspective, but I don't necessarily consider it in my dosing recommendations. I usually spend the most time looking at what has been going on for the past two weeks, and since Bubba had surgery 9 days ago I would probably look mostly at the last 7-8 days. So yes, he got green on a lower dose in the past, but that was then and this is now. Yes he may have been unpredictable in the past, but right now he's pretty darn predictable (basically flat yellow). You say he tends to be higher in one cycle than the other, but really most of his preshots in the past 7-8 days are nearly the same. He is pretty much yellow and some pink, so I wouldn't worry too much about any variance right now. And you're right, if he decides yellow is normal then it could become harder to break through it as time goes on.
What I would do is deal with the "now." For Bubba, that probably means dealing with the flat yellows. Get through that, then deal with whatever his next trick is. His past patterns may or may not return once whatever is causing this resistance goes away (could be residual pain, or meds, some glucose toxicity, or something else or nothing at all). You test enough to catch a breakthrough when it happens, and you know how to deal with low numbers should you find them.
About sliding scales, for what it's worth those were the norm in the PZI ISG when I first came to FDMB eons ago. Most of the PZI users on Health were more conservative and basically went with Start Low, Go Slow. I didn't do it with Lucy because at that point I was still too overwhelmed to think that hard. When the original Idexx PZI was discontinued and Prozinc came out, people here got away from the sliding scale because they weren't sure how similar Prozinc would be to PZI. Lots of people (including me) switched to Lantus at that time and the sliding scale largely disappeared from FDMB. I haven't used Prozinc at all so I have no opinion on how to best use it or whether it is similar to PZI. I did use a sliding scale for KK (on compounded PZI) for about a week because that's what insulin his foster mom had him on, but he only came with a few days' worth of insulin so when that ran out I went with what I knew better (Levemir).
Anyway, those are my thoughts. Good luck with Bubba!
