Clinical and Laboratory Correlates of Excessive and Persistent Blood Glucose Elevation During Cardiac Surgery in Nondiabetic Patients: A Retrospective Study

Background: Hyperglycemia during cardiac surgery in nondiabetic patients is a common finding associated with increased morbidity and mortality, but its predictors have not been studied to date. Methods: To identify clinical and laboratory correlates of excessive and persistent blood glucose (BG) elevation during cardiopulmonary bypass (CPB) in nondiabetic patients, the authors reviewed 195 medical records. After exclusion of patients with preoperative BG >120 mg/dL and with missing preoperative BG data, 163 cases were included in the final analysis. Patients with BG ≥200 mg/dL during CPB and remaining ≥200 mg/dL either during or after CPB or at the first postoperative measurement formed the study group (n = 35). One case had insufficient data to determine group assignment and was not used in comparison. The remaining patients formed the control group (n = 127). Results: BG was ≥200 mg/dL at least once perioperatively in 114 of 163 (70%) patients. It occurred during CPB in 100 of 163 (61%) cases and persisted beyond CPB in 35 of 162 (22%) cases. Univariate analysis revealed a significant difference between groups in preoperative use of angiotensin-converting enzyme (ACE) inhibitors (51% v 29%, p = 0.02), total dose of phenylephrine during CPB (14.1 mg ± 10.6 mg v 10.3 ± 9.6 mg, p = 0.003) and pre-CPB BG (123 ± 22 mg/dL v 113 ± 18 mg/dL, p = 0.02). In multivariate analysis, ACE inhibitors and pre-CPB BG remained statistically significant. Conclusions: Nondiabetic patients with excessive and persistent BG elevation during cardiac surgery are more likely to take ACE inhibitors preoperatively, show relatively high pre-CPB BG, and possibly require higher doses of vasoconstrictors during CPB.