Combined epidural-general anesthesia [CEGA] in patients undergoing pancreatic surgery: comparison between bupivacaine 0.125% and 0.25%

ABSTRACT

Major abdominal surgery results in homodynamic instability mainly due to endogenous prostacyclin release, bleeding, major intercompartemental fluid shift and the hormonal surgical response. This study compared the effects of low thoracic epidural anesthesia with 0.125% and 0.25% bupivacaine on haemodynamic variables, sevoflurane requirements, and stress hormone responses during pancreatic surgery under combined epidural-general anaesthesia [CEGA]. Forty patients undergoing different pancreatic surgery were randomly allocated into two equal groups to receive 10 ml of either isobaric bupivacaine 0.125% [group I] or 0.25% [group II] by low thoracic epidural with sevoflurane general anaesthesia. Sevoflurane was adjusted to achieve a target bispectral index [BIS] of 40-60. Measurements included the inspired [F'SEVO] and the end-tidal sevoflurane concentrations [E'SEVO], blood pressure [BP] and heart rate [HR] before surgery and every 5 min during surgery for 2 h, and stress hormones. Plasma samples for stress response evaluation were taken before and 1 and 2 h after the start of surgery for measurements of epinephrine, and cortisol. During surgery, both groups were similar for HR, BPand BIS, but [EISEVO] and [E'SEVO] were significantly higher and more fluctuated with bupivacaine 0.125% than with 0.25%. Moreover, the total amount of propofol used for induction of general anesthesia and the total fentanyl used during anesthesia were significantly low in 0.25% bupivacaine group. Intraoperative requirements of ephedrine were higher in 0.25% bupivacaine group, Intraoperative blood loss and fluid requirements were significantly increase in 0.125% group. Plasma concentrations of epinephrine and cortisol were found to be higher with bupivacaine 0.125% as compared with 0.25%. Combined thoracic epidural-general anesthesia [CEGA] for pancreatic surgery, with 0.25% bupivacaine significantly reduces sevoflurane requirements, blood loss and fluid requirements. In addition, bupivacaine 0.25% suppressed the stress hormone responses better than 0.125% did. However this was on the expenses of more ephedrine requirements