A dose-finding study of spinal ropivacaine when combined with fentanyl for cesarean section / 中华麻醉学杂志

ABSTRACT

Objective To investigate the dose-response relationship of spinal ropivacaine when it is combined with spinal fentanyl 20 ?g for cesarean section. Methods Sixty ASA Ⅰ-Ⅱ full-term nulliparous women undergoing cesarean section under combined spinal-epidural anesthesia (CSE) were randomized to receive spinal fentanyl 20?g and ropivacaine 10 mg (group A, n = 20) or 13 mg (group B, n = 20) or 15 mg (group C, n = 20) . Spinal puncture was performed at L2-3 interspace. A catheter was inserted 3 cm in the epidural space cephalad. If spinal analgesia was inadequate 2 % lidocaine was given epidurally. The clinical efficacy was rated based on analgesia, muscle relaxation and visceral traction response as Ⅰ-Ⅳ (Ⅰ= worst, Ⅳ= best). The probit log dose-response relationship was determined. The ED50 and ED95 of ropivacaine for spinal anesthesia when combined with spinal fentanyl 20 ?g were calculated. Complications such as hypotension, nausea, vomiting and shivering were recorded. Results The three groups were comparable with respect to age, sex, body weight, height and duration of operation. The clinical efficacy in group B and C was significantly better than that in group A ( P