Effectiveness of preemptive analgesia with epidural morphine in elective thoracic surgery

Abstract

Introduction: Postoperative pain has an acute nature. Its origin is the result of nociceptive stimulation due to the aggression caused by the surgery. Objectives: To compare the effectiveness of analgesia with preemptive and postoperative epidural morphine in the treatment of acute postoperative pain in elective thoracotomy. Method: A quasi-experimental study to compare the effectiveness of preemptive and postoperative analgesia with epidural morphine 4mg in the management of pain associated to elective thoracotomy was conducted at the Arnaldo Milian Castro Provincial University Hospital in Santa Clara from January 2006 to January 2009. The study included 62 patients who were surgically intervened. They were divided into two groups. Both groups received thoracic epidural analgesia with lyophilized morphine 4mg , one pre-emptively and postoperatively the other. With the patient's informed consent, the mean arterial pressure, heart rate and pain intensity (by means of the visual analogue scale) were recorded at 8 times in the first 24 hours after surgery. Results: A significant decrease of the intensity of postoperative pain was achieved in the group of patients that received the preemptive analgesia, with a reduction of the need of rescue analgesia and improved postoperative satisfaction. There were no hemodynamic changes or significant adverse effects in both analgesic modalities. Conclusions: analgesia with morphine, both preemptive and postoperative, is effective in controlling postoperative pain in this kind of procedures; however, it was demonstrated that preemptive analgesia is more effective in this type of surgery.