The effect of combined preinduction thoracic epidural anaesthesia and glucocorticoid administration on perioperative interleukin-10 levels and hyperglycemia. A randomized controlled trial.

AIM

Anti-inflammatory cytokines such as interleukin-10 (IL-10) play a key role in the anti-inflammatory cascade after cardiopulmonary bypass (CPB). Even moderate hyperglycemia can increase mortality/morbidity, stroke, and myocardial infarction after coronary artery bypass grafting (CABG). The purpose of our study was to investigate whether preinduction thoracic epidural anesthesia (TEA) and preinduction glucocorticoid have an effect on perioperative anti-inflammatory and perioperative hyperglycemia in patients undergoing CABG with CPB.

METHODS

Sixty low-risk patients (n=60) undergoing elective CABG were randomly allocated into 4 groups: Group corticosteroid (Group S) (n=15) received 6-methylprednisolone 15 mg/kg IV 60 min before induction; Group TEA+corticosteroid (Group TEA+S) (n=15) received 20 mg bupivacaine in bolus 60 min before induction followed by 20 mg/h bupivacaine infusion intraoperatively and postoperatively via epidural catheter. Group TEA (n=15) received 20 mg bupivacaine in bolus 60 min before induction followed by 20 mg/h bupivacaine infusion intraoperatively and postoperatively via epidural catheter. Group control (Group C) (n=15) received neither preinduction TEA nor a preinduction steroid. Blood samples were sequentially taken before surgery (baseline), before CPB, 1 h after CPB, in the intensive care unit (ICU) and 24 h after surgery from an indwelling radial arterial catheter.

RESULTS

Before CPB, circulating IL-10 levels were higher in groups TEA+S and S than in group C (P<0.05). At 1 h after CPB, IL-10 levels were higher in groups TEA+S and S than in group C (P<0.001). Before CPB and at 1 h after CPB, IL-10 levels were lower in group TEA than in group C (P<0.05). Before CPB, glucose levels were higher in group S than in groups TEA, C or TEA+S (P<0.001; P<0.05). There was no significant difference in glucose levels between groups TEA, TEA+S and C. At 1 hour after CPB, glucose levels were significantly lower in groups TEA and TEA+S than in groups S and C (P<0.001; P<0.05). At 1 hour after CPB, glucose levels were significantly higher in group S than in group C (P<0.05). At ICU, glucose levels were significantly lower in group TEA than in groups S, C and TEA+S (P<0.001; P<0.05).

CONCLUSION

The study results show that preinduction TEA improves glucose homeostasis during the perioperative 24-h period in CABG surgery. In addition, we found that while preinduction TEA reduced blood IL-10 levels, preinduction glucocorticoid and TEA+S increased the circulating levels of IL-10.