Achieving a Preoperative Target HbA1c of < 69 mmol/mol in Elective Vascular and Orthopedic Surgery: A Retrospective Single Center Observational Study

Diabetes mellitus (DM) is present in 10–15% of the surgical population. It is a known risk factor for adverse postoperative outcomes. UK perioperative guidance recommends optimizing glycemic control preoperatively, aiming for a target glycated hemoglobin (HbA 1c ) of < 69 mmol/mol. However, real-world compliance with this guidance remains unknown. The aim of our study was to determine how many patients with DM undergoing elective orthopedic and vascular surgery had a preoperative HbA 1c of < 69 mmol/mol. We also reviewed the surgical reasons for non-concordance with the recommended preoperative HbA 1c target. This was a retrospective observational study of 1000 consecutive patients who had been referred for elective vascular and orthopedic surgery at a large tertiary center. Data were collected on these patients, both those with and without DM, between January 2016 and February 2017. Electronic databases were used to collect information on the patients’ preoperative HbA 1c concentration and to determine whether there was a resulting delay in surgery when the preoperative HbA 1c target of < 69 mmol/mol was exceeded. Of the 1000 patients referred for surgery (500 orthopedic and 500 vascular patients) included in the study, 201 (20%) had diabetes. Among these 201 people with DM, 155 (77%) had a preoperative HbA 1c < 69 mmol/mol. Among the 46 people with DM whose HbA 1c exceeded the recommended target, 41 were operated on despite the high HbA 1c level, and only five had their surgery deferred or canceled due to suboptimal preoperative glycemic control. Our data shows that the majority (77% ) of people undergoing elective vascular and orthopedic surgery were able to achieve a target HbA 1c of < 69 mmol/mol. The current preoperative guidance is therefore achievable in a real-life setting. However, as is stated in the national guidance, this target should only be used where it is safe to do so and a degree of clinical discretion is necessary.