The differential impact of two anesthetic techniques on cortisol levels in Nigerian surgical patients.

Background: Surgical procedures are associated with a complexity of stress response characterized by neurohumoral, immulogic, and metabolic alterations. Aim: The aim was to compare the effects on the stress response by isoflurane-based intratracheal general anesthesia (ITGA) and bupivacaine-based epidural anesthesia (EA), using cortisol as a biochemical marker. Materials and Methods: Following the approval of the Hospital Ethical Board, informed written consent from patients recruited into this study was obtained. One group received general anesthesia with relaxant technique (group A) while the other group had bupicaine epidural anesthesia with catheter placement for top-ups (group B) for their surgeries. Both groups were assessed for plasma cortisol levels - baseline, 30 minutes after skin the start of surgery and at skin closure. Results: There was no statistically significant difference in the baseline mean heart rate, mean arterial pressure (mean MAP) and the mean duration of surgery between the two groups; the baseline mean plasma cortisol level was 88.70 3.85 ng/ml for group A and 85.55 2.29 ng/ml for group B, P=0.148. At 30 minutes after the start of surgery the plasma cortisol level in the GA group was 361.60 31.27 ng/ml while it was 147.45 22.36 ng/ml in the EA group, showing a significant difference, P=0.001. At skin closure the mean plasma cortisol value of 384.65 48.04 ng/ml recorded in the GA group was found to be significantly higher than the value of 140.20 10.74 ng/ml in the GA group, P < 0.002. Conclusion: Using plasma cortisol as a measure, bupivacaine-based epidural anesthesia significantly reduces the stress response to surgical stimuli when compared with isoflurane-based tracheal general anesthesia.