Intraoperative glucose variability, but not average glucose concentration, may be a risk factor for acute kidney injury after cardiac surgery: a retrospective study

PurposeAltered perioperative glycemic control may contribute to the development of renal dysfunction in cardiac surgery patients. Nevertheless, whether it is intraoperative hyperglycemia or increased glucose variability that affects postoperative outcomes is not yet clear. The aim of this study was to assess the association of intraoperative glucose concentration and variability with acute kidney injury (AKI) after cardiac surgery.MethodsWe retrospectively reviewed the electronic medical records of 3,598 patients who underwent cardiac surgery between November 1, 2006 to December 31, 2016. The time-weighted average glucose (TWAG) and coefficient of variation of glucose measurements were both used as measures of intraoperative glucose control with multivariable logistic regression to evaluate their relationship to postoperative AKI.ResultsThe intraoperative glucose coefficient of variation was an independent risk factor for AKI after cardiac surgery (highest quartile odds ratio, 1.38; 95% confidence interval, 1.09 to 1.75; P = 0.01). Nevertheless, the intraoperative TWAG did not remain in the final multivariable model of postoperative AKI.ConclusionIntraoperative glucose variability, but not the average glucose concentration itself, may be a risk factor for AKI after cardiac surgery.