Perioperative Glycemic

Surgery and anaesthesia activate a stress response. Cortisol, catecholamines, glucagon, growth hormone, and inflammatory cytokines signal the liver to release glucose while making muscle and fat less responsive to insulin. The result is increased glucose production combined with insulin resistance. This can occur in a person with known diabetes, newly recognized diabetes, or no previous diagnosis of diabetes. A postoperative glucose elevation is therefore not automatically “just stress” and should not be dismissed. Hyperglycemia impairs neutrophil function, worsens inflammation, and interferes with tissue repair. It is associated with surgical site infection, delayed wound healing, longer hospital stay, and increased mortality. Stress hyperglycemia in someone without known diabetes can carry as much risk as hyperglycemia in someone with diabetes. The goal is not tight euglycemia at any cost. Overly aggressive insulin treatment can cause hypoglycemia, which may be difficult to recognize in a sedated, anaesthetized, or cognitively impaired patient. Perioperative management balances both hazards.