I was wondering what are some factors affecting post operative blood glucose levels?

Surgery and diabetes: Post op, the stress level is high, which will elevate glucose. Infection (if present) will elevate glucose, as will any tissue necrosis (if present). But then you are (usually) not eating. It is hard to precisely balance all this, which is why the post op blood glu levels need to be monitored and treated.

High glucose levels: One is certainly under a lot of stress post-surgery. To find out if diabetes was present prior to the surgery, and undiagnosed, ask the doctor to order a hemoglobin a!c (h) level. If elevated, the patient had diabetes for at least 3 months prior to the surgery. If not, check the h 1 month after the patient is discharged.