@furrypaul glad you survived, hope you’re all fit and well now.
Pumps are a real mystery to most medics outside the diabetes team (and I suppose why shouldn’t they be, they’re not particularly common and if your job is to operate on people you’ll see them very rarely).
High BGs increase the chances of infection, and also slow down healing/make it harder to get rid of any infection. All that sugar makes for a tasty place for infection to feast. In the mind of Drs who’ve once read a paragraph in a textbook on diabetes this translates as “all diabetics are a hotbed for infection” which isn’t strictly true. If it’s controlled there shouldn’t be an issue.