[Blood glucose, ACTH, cortisol, T4, T3 and rT3 after cholecystectomy. Comparative studies of continuous peridural anesthesia and neuroleptanalgesia]

Abstract

15 patients (12 women and 3 men) undergoing cholecystectomy were randomized into two groups. 8 patients were operated on under continuous thoracic epidural anaesthesia in combination with light general anaesthesia. Postoperatively they were kept painfree by continuous infusion of an 0.125% solution of bupivacaine via epidural catheter at a rate of 0.25-0.3 ml/kg X h over a period of four days. The 7 patients in the control group were operated on under neuroleptanalgesia. Piritramide was given for postoperative analgesia. All patients received 40 ml/kg X day of electrolyte solution during the period of investigation. Blood was collected at 8 am, 12 am, 4 pm, 8 pm, and 12 pm on the day of operation and on the third postoperative day, at 8 am on the first and second postoperative day, and at 8 am, 12 am, and 4 pm on the fourth postoperative day. Plasma glucose, ACTH, cortisol, T4, T3, and reverse T3 were measured. During the operation and for 12 h thereafter a mild hyperglycaemia was observed in the neuroleptanalgesia group but not in the epidural group. The differences were significant. A rise in ACTH was seen in both groups during and shortly after operation. The increase in cortisol concentration following this ACTH release was significant only in the neuroleptanalgesia, but not in the epidural group. From the first to the fourth postoperative day ACTH levels were low and cortisol concentrations within the normal range. On the third day it appeared that a diurnal variation in cortisol levels was again present. Cortisol suppression following the administration of 2 mg dexamethasone on the fourth postoperative day was detectable in both groups. Of the thyroid hormones, T4 remained unchanged and at a normal level during the investigation. T3 decreased and reverse T3 increased significantly, the maximum rise being observed on the second day. There were no differences between the groups. These changes are defined as low T3 syndrome, following caloric deprivation, injury, and stress. The metabolic and hormonal alterations caused by cholecystectomy are marked only during operation and shortly thereafter and only in this period are they influenced by epidural analgesia. From the first postoperative day onwards they are almost negligible so that a mitigation by using continuous epidural analgesia is not to be expected.