Background

Surgical outcomes are worse in people with diabetes, in part, because of the effects of hyperglycaemia, obesity and other comorbidities. Two important uncertainties in the management of people with diabetes undergoing major surgery exist: (1) how to improve diabetes management prior to an elective procedure and (2) whether that improved management leads to better post-operative outcomes.

Objective

The Optimising Cardiac Surgery ouTcOmes in People with diabeteS project aimed to assess whether a pre-operative outpatient intervention delivered by a multidisciplinary specialist diabetes team could improve diabetes management and cardiac surgical outcomes for people with diabetes. Although the intervention could be applied to any surgical discipline, cardiothoracic surgery was chosen because 30–40% of those undergoing elective cardiac revascularisation have diabetes.

Methods

The project had three phases: (1) designing the intervention, (2) a pilot study of the intervention and (3) a multicentre randomised controlled study in United Kingdom cardiothoracic centres to assess whether the intervention could improve surgical outcomes. The first two phases were completed, but the COVID-19 pandemic and its subsequent effects on cardiothoracic services and research capacity in the United Kingdom meant that the randomised controlled study could not be undertaken.

Intervention development

Two rapid literature reviews were undertaken to understand what factors influence surgical outcomes in people with diabetes and what interventions have previously been tested. The Optimising Cardiac Surgery ouTcOmes in People with diabeteS intervention was based on an existing nurse-led outpatient intervention, delivered in the 3 months before elective orthopaedic surgery. This intervention reduced pre-operative glycated haemoglobin and reduced length of stay. We undertook a survey of United Kingdom cardiothoracic surgeons, which found limited and inconsistent pre-operative management of people with diabetes awaiting cardiothoracic surgery. A prototype intervention was developed following discussions with relevant stakeholders.

Pilot study

The pilot feasibility study recruited 17 people with diabetes and was undertaken by the diabetes and cardiothoracic surgery departments at University Hospital Southampton NHS Foundation Trust. Biomedical data were collected at baseline and prior to surgery. We assessed how the intervention was used. In-depth qualitative interviews with participants and healthcare professionals explored perceptions and experiences of the intervention and how it might be improved.

Thirteen people completed the study and underwent cardiothoracic surgery. All components of the Optimising Cardiac Surgery ouTcOmes in People with diabeteS intervention were used, but not all parts were used for all participants. Minor changes were made to the intervention following feedback from the participants and healthcare professionals. Median (interquartile range) glycated haemoglobin fell 10 mmol/mol (3–13) prior to surgery. The median duration of admission for surgery was 7 (interquartile range 6–9) days.

Multicentre randomised controlled study of the United Kingdom cardiothoracic centres

We could not proceed to the multicentre randomised controlled study because of the impact of COVID-19 on the delivery of cardiothoracic surgical services and research capacity.

Conclusion

There remains an urgent need to improve the surgical outcomes for people with diabetes. This project demonstrated that it is possible to develop a clinical pathway to improve diabetes management prior to admission.