ABSTRACT
BACKGROUND: Coronary artery bypass graft surgery with cardiopulmonary bypass induces a systemic inflammatory response. However, when thoracic epidural anaesthesia is administered as part of a combined anesthetic technique, the stress response associated with the cardiopulmonary bypass (CPB) may be attenuated. METHODS: Twenty-two patients undergoing elective coronary artery bypass graft surgery were randomized to receive either balanced general anesthesia with 7-20 microg/kg fentanyl (GA group) or combined anesthesia with 3-6 microg/kg fentanyl and an epidural bolus of 0.33% bupivacaine followed by a continuous perfusion of 0.175% bupivacaine, which was continued up to 48 hours after surgery (TEA group). The hemodynamic levels, troponin I, C-reactive protein (CRP), fibrinogen, leukocyte and platelet counts were recorded preoperatively, and 5 h, 16 h, 24 h, and 36 h after termination of the cardiopulmonary bypass. The time to tracheal extubation and cardiopulmonary complication rate were measured postoperatively. Data were analyzed with the Student's t and Mann Whitney tests, as appropriate. Differences were considered significant at P<0.05. RESULTS: All parameters significantly increased following CPB. The increase in CRP levels were lower in the TEA group at 16 hours (P=0.048). The increase of fibrinogen levels were lower in the TEA group at 24 hours (P=0.047). No differences were found in troponin levels between groups during the study. No significant differences were observed in extubation times (GA group 750+/-144 min; TEA group 702+/-451 min). CONCLUSION: Thoracic epidural anaesthesia, as a part of a combined anesthetic technique, attenuated the inflammatory response (CRP and fibrinogen levels) to cardiac surgery with cardiopulmonary bypass. However, this effect was not reflected in a decrease of troponin I levels, reduced incidence of complications, or in an earlier extubation time.
