Background: Not only perioperative high blood glucose but also glycemic variability (GV) is significantly associated with mortality in cardiac surgery. Perioperative hyperglycemia in diabetes (DM) patients is well-known, however, there is less information in non-diabetes (non-DM) patients.

Objective: The present study objectives were to show the variations of perioperative blood glucose, to compare the characteristics, frequency, and severity of hyperglycemia, and to compare GV between non-DM and DM undergoing cardiac surgery.

Materials and Methods: A prospective observational study was conducted between January 2016 and July 2018. Cardiac-surgery patients, age 20 to 80 years, undergoing cardiopulmonary bypass (CPB) were recruited. The differentiation between the DM and the non-DM was based on standard diagnosis. Perioperative blood glucose was measured every 30 minutes by POCT-glucose and controlled by insulin based on the institutional protocol. GV measures were standard deviation (SD), coefficient of variance (CV), and mean absolute glucose (MAG). Characteristics of blood glucose changes were demonstrated, which were related to events or surgical procedure. Comparison of blood glucose, GV, and events of hyperglycemia were carried out using Student t-test or chi-square test as appropriate.

Results: Perioperative hyperglycemia were 60% in DM and 30% in non-DM. Hyperglycemia started at the beginning of the operation in DM and in late CPB in non-DM. Inotropes or vasopressors was associated with sharp shooting increases of blood glucose. Hyperglycemia with more severity was commonly found during the early postoperative period in both DM and non-DM. The GV of DM was higher than in non-DM. The average MAG were 31.98 and 28.05 mg/dl/hour in DM and non-DM, which was the only measure that could significantly differentiate DM and non-DM.

Conclusion: Perioperative hyperglycemia in cardiac surgery occurred in both non-DM and DM despite the treatment by insulin infusion. Inotropes or vasopressors infusion was significantly related to a sudden hyperglycemia. MAG might be a better monitor of GV than SD and CV during cardiac surgery.

Trial registration: Thai Clinical Trials Registry, TCTR 20190411005

Keywords: Hyperglycemia, Glycemic variability, Mean absolute glucose, Cardiac surgery

DOI: doi.org/10.35755/jmedassocthai.2020.08.11095

Received 27 Jan 2020 | Revised 13 Apr 2020 | Accepted 17 Apr 2020