Role of epidural analgesia on endocrine & metabolic responses to surgery

Serum levels of cortisol, T3, T4 and blood levels of glucose, lactate and pyruvate were measured 15 min before anaesthesia, 15 and 60 min after skin incision and at 2 h after surgery, in 16 patients undergoing elective surgery on lower extremities either under epidural analgesia (group I) or general anaesthesia (group II). The results showed that as long as the effect of epidural analgesia persisted, it could inhibit the increases in cortisol and blood glucose and the decreases in T3 levels, observed under general anaesthesia. This is probably because of the blocking effect of epidural analgesia on the afferent neurogenic impulses from the area of surgery. T4, lactate and pyruvate levels were not affected to any significant extent. These observations could be of value in the operative management of patients with diabetes mellitus and others with a high surgical morbidity.