Effect of lumbar epidural anaesthesia on plasma cortisol levels in children.
The cortisol response to surgery was studied in two groups of children one to eight years old during the first 24 hours after lower abdominal or peripheral surgery. The children were randomly allocated to a control (C) group (n = 6) or an epidural (E) group (n = 7). In Group C, surgery was performed under general anaesthesia and postoperative pain relief was achieved by using non-narcotic analgesics only. In Group E, lumbar epidural anaesthesia was combined with light general anaesthesia and postoperative pain relief was achieved by intermittent doses of bupivacaine administered through an epidural catheter. Cortisol levels were assessed before surgery (C), at the end of surgery (H0), at the 3rd, 6th, 12th and 24th postoperative hours (H3, H6, H12, H24). In Group C, cortisol levels increased significantly at H0, H3 and H6, whereas in Group E, a significant decrease was observed at H0 and a significant increase at H12. Mean cortisol values at H0 and H24 were significantly lower in Group E, when compared with those measured in Group C. In Group E, all postoperative cortisol values remained within the normal range, despite the low level of sensory blockade achieved. This suggests that minimal doses of epidural bupivacaine are effective in decreasing the endocrine stress response to surgery in children. This could be of clinical relevance in high-risk children with poor nutritional status. In Group C, the cortisol response remained altered for a longer period of time.