Minimal low-flow isoflurane-based anesthesia benefits patients undergoing coronary revascularization via preventing hyperglycemia and maintaining metabolic homeostasis

Abstract

Background: The objectives of this study were to determine whether minimal low-flow isoflurane-based anesthesia could be a feasible technique for patients undergoing coronary artery bypass graft surgery. It is hypothesized that isoflurane-based anesthesia facilitates an agreeable recovery from surgery is mediated through preventing hyperglycemia and metabolic disturbance associated with cardiopulmonary bypass.

Methods: 107 consecutive patients were randomly assigned to two groups, i.e., isoflurane-based anesthesia group (n = 54) and fentanyl-based anesthesia group (control group, n = 53). In isoflurane-based anesthesia group, patients received isoflurane from induction up till departure from operating room to intensive care unit (ICU). In the control group, fentanyl (66.4 +/- 3.2 micrograms/kg) and midazolam (320 +/- 20 micrograms/kg) were administered to anesthetize the patients during the operation.

Results: Patients with isoflurane-based anesthesia required less dopamine (0.6 +/- 0.2 vs. 4.2 +/- 0.4 micrograms/min) and dobutamine (0.4 +/- 0.2 vs. 4.1 +/- 0.5 micrograms/min); they could be extubated earlier (7.9 +/- 1.0 vs. 35.1 +/- 2.9 h), and had a shorter stay at ICU (2.2 +/- 0.2 vs. 4.8 +/- 0.4 days). In addition, occurrence of hyperglycemia (167 +/- 7.7 vs. 243 +/- 9.5 mg/dl) and bicarbonate requirement (128 +/- 7.0 vs. 313 +/- 22.0 mEq) were less in patients with isoflurane-based anesthesia as compared with those in fentanyl group.

Conclusions: These results demonstrate that isoflurane, not fentanyl, benefits patients undergoing coronary artery bypass grafting surgery. This benefit perhaps is mediated through maintaining hemodynamic stability and metabolic homeostasis and preventing hyperglycemia.