Patient-controlled epidural fentanyl following spinal fentanyl at Caesarean section

Spinal fentanyl can improve analgesia during Caesarean section. However, there is evidence that, following its relatively short-lived analgesic effect, there is a more prolonged spinal opioid tolerance effect. The effectiveness of postoperative epidural fentanyl analgesia may therefore be reduced following the use of spinal fentanyl at operation. This randomised, double-blind study was designed to assess whether patient-controlled epidural fentanyl could produce effective analgesia following 25 microg of spinal fentanyl at operation. Patients undergoing elective Caesarean section received spinal bupivacaine combined with either fentanyl 25 microg (fentanyl group; n = 18) or normal saline (saline group; n = 18). Patient-controlled epidural fentanyl was used for postoperative analgesia. The fentanyl group used a mean of 23.4 (SD 14.5) microg x h(-1) of fentanyl, compared with 27.0 (10.8) microg x h(-1) for the saline group (p =0.41). Using a 0-100 mm visual analogue score for pain, the maximum pain score recorded at rest for the fentanyl group was median 24 [IQR 15-35] mm, compared with 15 [13-45] mm for the saline group (p = 0.41). The maximum pain score recorded on coughing for the fentanyl group was 29 [24-46] mm, compared with 27 [19-47] mm for the saline group (p = 0.44). Nine of the fentanyl group rated postoperative analgesia as excellent and nine as good, compared with 10 of the saline group who rated it as excellent and eight as good (p = 0.74). Epidural fentanyl can produce effective analgesia following the use of 25 microg spinal fentanyl at Caesarean section.