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

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.