Postoperative analgesic requirements after subarachnoid or epidural anesthesia with ropivacaine 0.75% in cesarean section. A double-blind randomized trial

Abstract

Objective: Postoperative analgesic requirements and pain scores were compared after subarachnoid versus epidural anesthesia with plain ropivacaine 0.75% for elective cesarean section.

Study design: Ropivacaine 0.75% was randomly administered for subarachnoid or epidural anesthesia in 108 parturients, scheduled for cesarean section. Times for the sensory block to reach T4 level and to regress to T6 level were recorded. At 2, 4, 8 and 24 h postoperatively, pain scores at rest and cough, morphine consumption as well as patient satisfaction, incidence of headache, nausea and/or vomiting were measured.

Results: Median (min-max) time for the sensory block to reach T4 was 7 (3-0) min versus 24 (16-73) min and to regress to T6 was 126 (70-332) min versus 200 (98-439) min in the subarachnoid and epidural groups, respectively (p=0.001). Although the subarachnoid had more analgesic consumption than the epidural group at 2 and 4 h postoperatively (7.3±4.7 vs. 1.8±2.4 mg, p=0.001 and 9±5.7 vs. 3.3±3.8 mg, p=0.001, respectively) no difference was observed at 8 or 24 h postoperatively (p=0.14 and p=0.38, respectively). VAS scores at rest and after cough (p=0.56, p=0.35, respectively), patient satisfaction (p=0.61), incidence of headache (p=1.0), nausea and/or vomiting (p=0.78) did not differ between the two groups.

Conclusions: Postoperative pain, analgesic requirements, patient satisfaction and adverse effects did not differ when subarachnoid or epidural anesthesia with ropivacaine 0.75% was used for elective cesarean section. Nevertheless, subarachnoid provides faster onset and offset of the block, compared to epidural anesthesia. The key limitation of this study is the lack of postoperative serum ropivacaine measurements taken with concurrent pain score measurements.