The impact of general anesthesia applied alone or with epidural anesthesia on stress response caused by laparoscopic cholecystectomy, using hormonal, metabolic and inflammatory markers.

Patients undergoing laparoscopic cholecystectomy will be randomly assigned, to receive either general anesthesia or lumbar epidural anesthesia supplemented by general anesthesia. In general anesthesia group, following preoxygenation and an intravenous induction sequence consisting of propofol (2.5 mg/kg), lidocaine (1-1.5 mg/kg), fentanyl (2 microg/kg) and cis-atracurium (0.2 mg/kg), laryngoscopy and orotracheal intubation will be performed. In lumbar epidural anesthesia with supplemental general anesthesia group, an epidural catheter will be placed through the intervertebral space between T12 and L1 or L1 and L2 before induction of anesthesia. Then, a bolus dose of ropivacaine 10% (15 +/- 2 ml) will be injected while epidural anesthesia will be considered as adequate when sensory blockade reaches the T4 level. Induction of anesthesia will be identical to the one previously described for general anesthesia group. In both groups, blood samples for resting plasma concentrations of cortisol, human growth hormone, prolactin, glucose and C-reactive protein determination, will be collected at 9 AM on the day prior to surgery, intraoperatively (just before termination of pneumoperitoneum) and on the first postoperative day. Furthermore, intraoperative hemodynamic data will be recorded on seven predefined time points: following anesthesia induction, during institution of CO2 pneumoperitoneum, 15 minutes, 30 minutes, 45 minutes and termination of pneumoperitoneum and end of surgical procedure.