Continuous-plus-on-demand Epidural Infusion of Morphine for Postoperative Pain Relief by Means of a Small, Externally Worn Infusion Device

Abstract

Patients received an initial bolus epidural injection of 2 mg morphine-hydrochloride followed by a continuous-plus-on-demand epidural infusion of a 0.25% morphine-hydrochloride solution by means of a small, externally worn infusion device, for constant pain relief after abdominal operations. Mean morphine consumption on the operation day (until 0800 h on the 1st postoperative day) was 4.8 .+-. 0.2 mg, on the first postoperative day (until 0800 h on the 2nd postoperative day) 1.9 .+-. 0.2 mg, and on a 2nd postoperative day until 2000 h, 0.6 .+-. 0.1 mg. The mean morphine consumption over 50 h was 7.1 .+-. 0.3 mg; in the first 25 h and in the following 25 h after the operation, 5.44 .+-. 0.3 mg and the significantly lower amount of 1.64 .+-. 0.2 mg morphine, respectively, were consumed (P < 0.001). There were no serious side effects. Serum levels of ree, unmetabolized morphine immunoreactivity decreased during the treatment. The described method is recommended for treating postoperative pain, as it offers ocnstant analgesia and the possibility of individualized treatment.