Haemoglobin A1c as a predictor of postoperative hyperglycaemia and complications after major colorectal surgery

Abstract

Abstract Background Hyperglycaemia following major surgery increases morbidity, but may be improved by use of enhanced-recovery protocols. It is not known whether preoperative haemoglobin (Hb) A1c could predict hyperglycaemia and/or adverse outcome after colorectal surgery. Methods Some 120 patients without known diabetes underwent major colorectal surgery within an enhanced-recovery protocol. HbA1c was measured at admission and 4 weeks after surgery. All patients received an oral diet beginning 4 h after operation. Plasma glucose was monitored five times daily. Patients were stratified according to preoperative levels of HbA1c (within normal range of 4·5–6·0 per cent, or higher). Results Thirty-one patients (25·8 per cent) had a preoperative HbA1c level over 6·0 per cent. These had higher mean(s.d.) postoperative glucose (9·3(1·5) versus 8·0(1·5) mmol/l; P < 0·001) and C-reactive protein (137(65) versus 101(52) mg/l; P = 0·008) levels than patients with a normal HbA1c level. Postoperative complications were more common in patients with a high HbA1c level (odds ratio 2·9 (95 per cent confidence interval 1·1 to 7·9)). Conclusion Postoperative hyperglycaemia is common among patients with no history of diabetes, even within an enhanced-recovery protocol. Preoperative measurement of HbA1c may identify patients at higher risk of poor glycaemic control and postoperative complications.