Background:

Glycaemic control at around the time of surgery is a critical part of surgical care in diabetic patients. Surgery is disruptive to the patients’ usual diabetic management and glucose homeostasis, often resulting in hyperglycaemia perioperatively. Hyperglycaemia has been associated with increased postoperative mortality and morbidity, as well as worse surgical outcomes in both cardiac and non-cardiac surgery. Studies have shown that treating hyperglycaemia can reduce the risk of these adverse events.

Despite earlier studies in the intensive care unit (ICU) setting, subsequent trials were not able to demonstrate improved outcomes with the use of intensive insulin therapy, which aimed for stricter glycaemic control (4.5–6.0 mmol/L). Whilst the optimal blood glucose concentrations are still unknown, current literature supports the use of moderately strict glycaemic control (5.0–10.0 mmol/L) via a basal-bolus insulin regimen, so as to balance the risks of inducing hypoglycaemia with the benefits of avoiding hyperglycaemia.

This audit aims to study the prevalence of hyperglycaemia in diabetic elective surgical patients at the Royal Melbourne Hospital (RMH), and will provide the initial data required for future systematic reviews. This audit ultimately aims to raise the standards of care for diabetic surgical patients.

Methods:

Patients undergoing elective surgery at RMH with a diagnosis of diabetes mellitus will be included. Preoperative blood sugar levels (BSLs) in diabetic patients will be assessed against the gold standard of 100% of preoperative BSLs being between 5 and 10 mmol/L.  BSLs will be collected on 200 consecutive eligible patients, and data that is confined to what is normally collected during routine care will be recorded from medical records. No intra- or post-operative data will be recorded. We anticipate about 25% of the patients will be hyperglycaemic.

Conclusion:

Hyperglycaemia is a common occurrence in diabetic surgical patients. One of the main findings of this audit is that approximately one third of all diabetic elective non-cardiac patients present with hyperglycaemia (>10.0 mmol/L) on the day of surgery. However, there is an underutilisation of the existing protocol, as hyperglycaemia was treated in 15% of patients.