Analgesic Effects according to the Dose of Continuous Epidural Infusion of Morphine and Clonidine after Epidural Anesthesia for Cesarean Section

Lee, Ji Hyang; Lee, Yoon Ji; Lee, Sang Gon; Min, Byung Woo

Abstract

BACKGROUND: Epidurally administered clonidine represents an approach to control the pain after cesarean section that produces analgesia by an alpha 2-adrenergic mechanism and may provide postoperative analgesia without nausea, pruritus, and respiratory depression associated with systemic or intraspinal opioid administration. This study was undertaken to evaluate the analgesic effect according to the dose of appropriate bolus and the combination of epidural morphine and clonidine after cesarean section. METHOD: Forty five women, ASA physical status 1 or 2, scheduled for elective cesarean section were randomly assigned to receive epidural administration for postoperative pain control. Group A (n=15) received 1 mg morphine and 75 g clonidine bolus followed by 4 mg morphine and 150 g clonidine. Group B received 2 mg morphine and 75 g clonidine bolus followed by 4 mg morphine and 300 g clonidine. Group C received 3 mg morphine and 75 g clonidine bolus followed by 4 mg morphine and 450 g clonidine. Each combination of drug was injected at Bromage scale 1 after surgery.
RESULTS
All groups showed relatively stable hemodynamic status. Analgesic effect was significantly better in Group B and C than Group A (p<0.05). Sedative effect was not a problem in all groups. The incidence of side effects in Group C was more than Group B, which than Group A, but almost cases did not require treatment.
CONCLUSION
2 mg morphine and 75 g clonidine bolus followed by 4 mg morphine and 300 g clonidine with excellent analgesic effect and less side effects is considered as adequate dose in postoperative pain control after cesarean section with epidural anesthesia.