Improving Blood Glucose Level Control Before Surgery

Published 26 April 2018. Last updated 10 May 2018.

Prince of Wales Hospital screened all patients booked for elective cardiac surgery, to diagnose diabetes and identify those requiring blood glucose level control before admission.


To reduce the number of diabetic patients who are admitted for a coronary artery bypass graft (CABG) and are hyperglycaemic (greater than 12 mmol/L), by 50 per cent within six months.


  • Reduces surgical site and other types of hospital-acquired infections.
  • Reduces hospital length of stay.
  • Reduces the risk of hospital readmission.
  • Improves health outcomes for the patient.
  • Reduces costs to the healthcare system.


In 2016, a high number of surgical site infections were observed in patients who had CABG surgery at Prince of Wales Hospital. A review of electronic patient records identified that insulin-dependant diabetes was common among patients with these infections.

A medical chart review also found a strong association between low blood glucose levels before surgery and higher rates of infections in hospital, which supports research that suggests diabetes and hyperglycaemia are both risk factors for infection.1

To improve patient outcomes and reduce the risk of infections, it was determined that a strategy was required to optimise blood glucose control before admission and reduce any gaps in blood glucose monitoring during the patient’s stay in hospital.


  • Patients were tested for glycosylated haemoglobin (HbA1c) and asked about their diabetes status in the preadmission clinic and in admission forms, with results captured in a database.
  • A trigger was added to the preoperative management process, to refer all newly-diagnosed diabetes patients (where HbA1c is more than 4.8mmol/mol or 6.5 per cent) and hyperglycaemic patients (where HbA1c is more than 75mmol/mol or nine per cent) for management, to make sure it is under control before surgery.
  • A reminder was added to the patient education pack about arranging an appointment with a general practitioner for a review of HbA1c test results and diabetes status, and to discuss the need for a diabetes care referral as soon as possible.


Implementation – The project is ready for implementation or is currently being implemented, piloted or tested.


  • July 2017: Mapping of preoperative management pathway
  • August 2017: Brainstorming workshop to identify the key drivers of the problem
  • September 2017: Implementation of HbA1c test request
  • March 2018: Interim report on baseline diabetes status and blood glucose level control
  • April 2018: Implementation of trigger for diabetes care and education pack
  • June 2018: Final project evaluation

Implementation sites

Department of Cardiothoracic Surgery, Prince of Wales Hospital, SESLHD


SESLHD Clinical Leadership Program


The project will be evaluated in three stages, involving all patients booked for an elective CABG with or without valve procedures at Prince of Wales Hospital.

Stage 1 (October 2017)

  • The proportion of patients with a HbA1c test requested before surgery and captured in the patient’s record increased from 25 per cent in July 2017 to 40 per cent in October 2017. The target of 100 per cent was not achieved, partly due to patients who were in the system before implementation.
  • The proportion of patients with a diabetes status recorded was 100 per cent by October 2017.

Stage 2 (April 2018)

This stage will measure compliance with Stage 1 as well as:

  • the proportion of patients diagnosed with diabetes (grouped by those who require insulin and those who do not)
  • the proportion of diabetic patients with suboptimal blood glucose level control, determined by a HbA1c or more than 75mmol/mol (nine per cent) within three months of surgery
  • the proportion of patients with suboptimal blood glucose level control who are referred for specialist diabetes care before surgery.

Stage 3 (June 2018)

This stage will test for significant associations between:

  • sternum surgical site infections and other hospital-acquired infections, as well as the following, adjusted by known surgical site infection risk factors:
  • all diabetes and insulin-requiring patients
  • suboptimal blood glucose level control (where HbA1c is more than 75mmol/mol or nine per cent) before and after surgery and within three months of surgery
  • diabetes management for insulin-requiring patients, including those managed by an endocrine specialist before admission, those managed by an endocrine registrar on admission but before surgery, and those not known to have received diabetes care before surgery
  • blood glucose level control and diabetes care as outlined above
  • the patient’s home, demographics and diabetes care as outlined above.

Lessons learnt

  • Ownership of the project must remain with cardiothoracic surgeons.
  • Mapping the preoperative work-up and post-operative care process is crucial to developing an agreed understanding of the project.
  • Make sure strategies are aligned to diabetes and surgical policies and guidelines in the facility.
  • Work with peak groups within and outside the local health district to spread the improvement across NSW.


  1. Martin E, Kaye K, Knott C et al. Diabetes and risk of surgical site infection: a systematic review and meta-analysis. Infection Control and Hospital Epidemiology 2016;37(1):88-99. DOI:10.1017/ice.2015.249

Further reading

  • Project poster
  • Davis N, Killen J, Lee T et al. ADS-ANZCA Perioperative Diabetes and Hyperglycaemia Guidelines. Melbourne VIC: Australian and New Zealand College of Anaesthetists; 2016.
  • Diabetes in Australia, Diabetes Australia
  • South Eastern Sydney Local Health District. Prince of Wales Hospital and Community Health Services. Surgery and Medical Procedures for Patients with Diabetes Mellitus. Clinical Business Rule. Kogarah NSW: SESLHD; 2016.


Michael Piza
District Manager of Clinical Performance, Improvement and Innovation Hub
South Eastern Sydney Local Health District
Phone: 0450 306 740


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