Pre- Versus Post-Incisional Epidural Morphine: Higher Postoperative Pain Perception and Extra Morphine Consumption

On the day of surgery, patients were brought to the operating room (OR) where routine monitors were placed and an epidural catheter was inserted at the level of L3-4 to a distance of 10 cm. All patients received two injections via the catheter: one injection contained 3 mg morphine (MO), and the other contained normal saline (NS) of the same volume. Patients were randomized to receive either NS preoperatively and MO postoperatively or vice versa. The first injection was administered 40 minutes before initiation of surgery, and the second one was given 15 minutes after surgery ended. All epidural catheters were removed before the patients were discharged from the post-anesthesia care unit (PACU).