Objectives

Diabetes and peri-operative hyperglycaemia are associated with increased morbidity and mortality following cardiac surgery. Despite this, specific guidance on peri-operative glycaemic management during cardiac surgery is lacking in United Kingdom (UK) and Europe. This narrative review presents evidence-based author recommendations for glycaemic control during adult cardiac surgery for those with, and without diagnosed diabetes.

Methods

A structured literature search was conducted using PubMed (1946–2025) and Embase (1974–2025), supplemented by Web of Science, Google Scholar, and thesis repositories. Studies reporting outcomes relating to diabetes status, HBA_1C, and/or blood glucose were included.

Results

Our recommendations include:- evaluating HbA_1c in all patients referred for cardiac surgery, regardless of diabetes status; HbA_1c target of 58 mmol/mol (7.5%) for patients with diabetes having elective cardiac surgery, maintenance of intra-operative blood glucose between 6–10 mmol/L (110–180 mg/dL) for all patients, and moderate rather than intensive peri-operative glycaemic control. We recommend patients with peri-operative hyperglycaemia be assessed by in-patient diabetes specialist team if available, and/or following discharge. All cardiac surgery hospitals in time, should aim to have a dedicated cardiac surgical diabetes working group, responsible for all cardiac surgery diabetes patients, and national outcome reporting.

Conclusions

Lack of consensus on peri-operative diabetes management for cardiac surgery exists in the UK and Europe. Our practical recommendations, including universal HbA_1c screening and glycaemic control targets, seek to standardize peri-operative management, improve clinical outcomes, and improve outcome reporting for this expanding vulnerable patient group.