Thoracic Epidural Anesthesia for Upper Abdominal Surgery and Postoperative Pain Control

상복부 수술을 위한 흉추 경막외 마취와 술후 통증관리

It has been standard practice in many institutions to use a combination of a light general anesthesia and an epidural block for lower abdominal and pelvic surgery. This combination of a balanced anesthesia can provide various benefits to the patient such as less bleeding in the surgical field, the use of a lower concentration of general anesthetics, less muscle relaxant, and post operative pain management. However, there are several problems associated with hemodynamics such as bradycardia and hypotension etc. In order to block the pain of the high surgical area with a lumbar epidural puncture postoperatively, a large volume of local anesthetic is required and consequently an extensive blockade of sympathetic, sensory and motor functions can occur causing motor weakness, numbness and postural hypotension. Therefore, the patient is unable to have early ambulation postoperatively. In this study, thoracic epidural catheterization was undertaken to locate the tip of the catheter exactly at the surgical level for upper abdominal surgery, and was followed by general anesthesia. Twenty-one patients scheduled for upper abdominal surgery were selected. Fifteen of them had hepatobiliary operations and the remaining 6 had gastrectomies. Thoracic epidural punctures were performed mostly at T9-T10 (57.1%) and T8-T9. Neuromuscular blocking agents were not used in half of the cases and the, mean doses of relaxant were $3.5{\pm}1.0mg$ in gastrectomies, and $2.7{\pm}0.9mg$ in cases of hepatobiliary operation. Epidural morphine was injected 1 hour before the end of the operation for postoperative pain control. Eight patients did not require additional analgesics and the mean dose of epidural morphine was $2.2{\pm}0.9mg$, and 13 cases were given 0.125% epidural bupivacaine when patients complained of pain. Their initial doses of epidural morphine were $1.9{\pm}0.4mg$ and the mean duration of bupivacaine was 6 hours 20 minutes${\pm}40$ minutes. In conclusion. thoracic epidural analgesia is valuable to reduce postoperative pain in patients with upper abdominal surgery, However, it is not easy to maintain this balanced anesthesia with high epidural analgesia-and light general anesthesia for upper abdominal surgery because of marked hemodynamic changes. Therefore, further practice will be required.