[Continuous infusion of morphine in use of pain relief after upper abdominal surgery]

This study was designed as a prospective randomized comparative trial of continuous infusion of morphine (CIM) controlled by a micro-electric pump and traditional intermitted intramuscle injection of pethidine (IMP) to relieve pain after surgery. 40 patients submitted from upper abdominal surgery were divided into two groups, 20 patient receiving CIM and others using IMP. The amount of morphine used during the 24 hours was 0.5 mg/kg in CIM group. In IMP group, 20 patients were given standard intramuscular dosages of 1.5 mg/kg of pethidine, then, every 4-6 hours repeatedly within 24 hours after operation. An analgesic scale was observed by WHO's pain score from I to IV degree. The result showed that all patients of CIM group had good analgesic effect (I and II degree), however, 10% of the patients in IMP group had only analgesic effect of I and II degree during the first 24 hours after operation. Their respiratory frequency, heart rate, BP and SpO2 had no significant difference in two groups. It woule appear that CIM is an efficacious and safe method for providing postoperative pain relief.