THE EFFECTS OF THORACIC EPIDURAL ANALGESIA ON POSTOPERATIVE COGNITIVE FUNCTION AFTER THORACOTOMY SURGERY

Purpose: To investigate the effects of thoracic epidural analgesia on postoperative cognitive functions after thoracic surgery. Materials and Methods: Thirty patients were included in this study after ethics committee approval was obtained. The patients were divided into two groups: those that received thoracal epidural analgesia (group E) and those that received remifentanyl analgesia (group R). All patients underwent a preoperative mini-mental test (MMT) in their hospital rooms before the operation and the same test was performed again on postoperative days 1 and 7 by the same anesthetist. Before anesthesia induction epidural catheterization was performed on thoracal 4-5 or 5-6 level and a 3 ml test dose (60 mg lidocaine + 15 mu g epinephrine) was applied to all patients. After the test dose, in group E 7 ml 0.25% isobaric bupivacaine bolus and then 5 ml/hour 0.25% isobaric bupivacaine infusion were started via an epidural catheter. No medication was applied to group Rafter the test dose via epidural catheter. Anesthesia was induced using thiopentone and pancuronyum. After double lumen tube intubation anesthesia was maintained with isoflurane (according to BIS value) in an oxygen-air mixture and only in group R 0.2 mu g kg(-1) min(-1) remifentanyl was used during the operation applied via intravenous infusion. Bolus 7 ml isobaric bupivacaine (0.25%) was applied via an epidural catheter during skin saturation in group R. At the end of the operation the muscle relaxant was reversed and the patients were extubated. Epidural morphine was used for postoperative analgesia in both groups. Results: In group R MMT-orientation day 7 scores were lower than their preoperative values and group E scores. MMT-recall day 7 scores were lower in group R than in group E. In group R MMT-language day 1 scores were lower than their preoperative and group E scores but day 7 scores were lower than group E day 7 scores. In both groups total MMT day 1 scores were lower than their preoperative scores, but, while day 7 group R scores were lower than their preoperative scores, group E scores returned to preoperative values. Conclusion: Thoracic epidural analgesia combined with general anesthesia improves postoperative cognitive functions after thoracic surgery.