I would take him into his ped, have them see the hospital reports and ask about the BG's. There are reasons other than Diabetes that can cause high Bg's but not alot of reasons and I too would want to make sure that it's been thoroughally checked out. The stuff he would have been given for respritory issues could since both adrenaline and steroids can cause bg's to increase, but a fully functional pancrease should correct for that and if they were inhaled not given systematically then not alot of the drugs would have been in his blodd streat to have a big impact on bg.
Also if they do think it is or might be diabetes make sure they check for the "Kir6.2 Mutations" - a specific genetic form that only starts in young babies. If he did have diabetes and did have this specific form, it can be treated well with an oral med and does not need insulin - which is a really good thing.
Hi, I'm not a medical professional, just the parent of a kid with diabetes. I concur with Cococay7's advice. It's entirely possible that stress on your son's system can cause increases in blood sugars that are not tied at all to the food eaten. Medicines can also raise blood sugars. And the advice about checking for that mutation is you do choose to visit your doctor is also good advice. That is a specific genetic condition which causes symptoms similar to type 1 diabetes, and it's only diagnosed in infants under a year old. If you have concerns and want to ease them, it's never wrong to visit your doctor to verify.