Fentanyl and the metabolic response to gastric surgery

The effect of the supplementation of nitrous oxide-oxygen anaesthesia with either 50 micrograms fentanyl/kg body weight or 0.5-1.0% halothane on the metabolic and hormonal response to gastric surgery was investigated in 16 patients. Those patients who received fentanyl showed a significant decrease (p less than 0.05) in the hyperglycemic response to surgery after 30 and 90 minutes and a significant decrease (p less than 0.05) in the plasma cortisol response after 30 minutes. Profound respiratory depression occurred at the end of surgery in all patients who were given fentanyl. This required the intravenous administration of naloxone and careful supervision in the early postoperative period. It is concluded that the transient metabolic and endocrine benefits produced by fentanyl do not compensate for the severe respiratory problems postoperatively and thus 'high-dose fentanyl' cannot be recommended for upper abdominal surgery.