Thoracic epidural versus intraperitoneal local anaesthetic for postoperative pain relief after laparoscopic or open cholecystectomy

ABSTRACT

Laparoscopic cholecystectomy [LPC] is increasingly used to treat symptomatic cholelithiasis. In this study, we compared the effects of cholecystectomy by subcostal incision to those of LPC on lung function and endocrine metabolic response. The effects of thoracic epidural analgesia and intraperitoneal local anaesthetics [0.25%] bupivacaine 20 ml for LPC were studied as well. Forty patients undergoing elective cholecystectomy under general anaesthesia were allocated into four study groups, group I, cholecystectomy by subcostal incision [CSI], group II, LPC, group III, LPC and epidural analgesia with 0.5% bupivacanie followed by continuous epidural infusion of 6 ml of 0.5% bupivacaine. Group IV, 0.25% bupivacaine 20 ml administered I.P., forced vital capacity [FVC] and forced expiratory volume in one second [FEV 1] were measured with the patients in a half-setting position. In all groups, sustained decrease in FVC, FEV1 were observed up to 24 hours after surgery. Reduction of FVC was significantly more in group I compared with groups II, III and IV [p < 0.05]. Two hours after surgery, FVC was decreased significantly in groups I, II, III and IV to 29.1, 58.3, 63.6 and 59% of the preoperative values respectively. At that time, FEV1 decreased to 27, 55, 60 and 56% of the preoperative values in groups I, II, III and IV respectively [p < 0.05]. In all groups, plasma glucose and cortisol levels increased after surgery compared with the baseline levels [p <0.05]. At 240 minutes after surgery, a small but significant decrease of cortisol was measured in group III [p < 0.05]. Patients in groups I, II and IV, received significantly more fentanyl during surgery and morphine postoperatively compared with patients in group III [p <0.05]. In group III, epidural analgesia decreased visual analogue pain scores [p <0.05], but there was no difference in pain scores between group I, II and IV. In conclusion, the endocrine metabolic response is not abolished after LPC. Thoracic epidural analgesia decreased postoperative pain and attenuated the metabolic endocrine response, but it did not improve lung function after LPC. Nevertheless, pulmonary function is significantly better after LPC than after cholecystectomy via subcostal incision