IV insulin is a strange character. Once injected into the bloodstream it essentially shuttles the glucose that’s in the blood into the cells but then any residual insulin is filtered out of the body very quickly. It peaks in about three minutes and is mostly gone in fifteen. Which means that any glucose that is still being released into the bloodstream will need more coverage almost immediately. There is a place for insulin IV but it’s almost always given by a continuous, ongoing drip with close monitoring, like an ICU.
I was actually quite pleased with how they handled things for my surgery. They had said to take just basal (or keep my pump on just basal), but I woke up in the middle of the night before surgery fairly high and so I took a correction bolus. It flattened out around 175 and I suspended the basal at that point. The doctors were all fine with letting me keep my pump/CGM on, and the anesthesia nurse asked for me to show her how it worked so they could both know what the alarms meant and know how to silence the high alarm if it kept going off. They had no issue with me handling my control and said “you know best how to do it because you do it everyday, so whatever you think is best”. After I came out of surgery I was quite a bit higher, and stayed in the 200s for about a day all due to the steroids they gave during the surgery. Now also granted this was outpatient at a surgery center and not inpatient, so not sure how a hospital would have handled it for overnight.
Just catching up on this thread after several days. Interesting stuff! Seems like the real takeaway is that there is a LOT of variability between institutions and even within institutions as to how they handle insulin-dependent PWDs, which for me means ASSUME NOTHING. Get with your physician and surgeon well ahead of time to find out what the hospital’s official guidelines are and jump through whatever hoops are required to allow you to manage your own treatment when you’re under their care. I had no idea this was even an issue, the first time I was in for a longer stay. If I had to do it again I would want to be sure I had whatever was necessary in writing before the day-of.
70% seems to be the standard basal advice given to pre-op patients at the University of Michigan hospital, where I had my surgery. The orthopedic, anesthesia and endocrine clinics came up with that one with the understanding that it was a good place to start and close surveillance would then fine tune as needed. 70% just happened to be spot-on for me and no tweaking was needed. Good luck with your surgery @Ruth4! I had mine four weeks ago today and life is good. Pretty much back to baseline activity and almost pain-free.