Effect of surgical trauma on plasma concentrations of cyclic AMP and cortisol

The response of plasma cortisol and cyclic AMP concentrations to surgical trauma was examined in 7 general surgical patients. Five patients made uncomplicated recoveries and showed peak cortisol levels at 6 hours postoperatively, returning to normal by 24 hours. On patient developed postoperative pneumonia and the plasma cortisol remained elevated up to 48 hours, and the final patient showed no cortisol response at all. The plasma cyclic AMP concentrations showed a consistent rise during the operation itself, which was statistically significant when compared with preoperative levels (P less than 0.0125). Concentrations had fallen to normal by 6 hours in all the cases, except in the patient who developed pneumonia, where the plasma cyclic AMP also showed a prolonged elevation. The significance of these findings requires further elucidation, but the temporal relationship of the cyclic AMP and cortisol peaks would support the hypothesis that cyclic AMP may play a part in the mediation of ACTH release following surgical trauma.