A comparative study of sequential epidural bolus technique and continuous epidural infusion.
BACKGROUND
In this randomized, double-blind study, the authors compared the effectiveness of a sequential epidural bolus (SEB) technique versus a standard continuous epidural infusion (CEI) technique of local anesthetic delivery. Both techniques used the same hourly dose of local anesthetic.


METHODS
Sixteen gynecologic patients undergoing abdominal surgery received postoperative epidural analgesia using 0.75% ropivacaine at a dose of 22.5 mg (3 ml) per hour. Patients were randomly assigned to one of two groups. In the SEB group (n = 8), patients received one third of the hourly dose every 20 min as a bolus. In the CEI group (n = 8), the hourly dose was administered as a continuous infusion. Analgesia was assessed by rest pain scored by a visual analog scale and pinprick to determine the number of separately blocked spinal segments on each side of the body. Doses of rescue medication for pain were also recorded.


RESULTS
The median number of blocked spinal segments was 19.5 (range, 18-24) in the SEB group and 11.5 (range, 10-18) in the CEI group (P < 0.001). The median difference in the number of blocked segments between the right and left sides was 0 (range, 0-1) in the SEB group and 2 (range, 0-6) in the CEI group (P < 0.04). No patients in the SEB group but one patient in the CEI group required rescue medication for pain. The visual analog scale pain score was 0 in both groups except for one patient in the CEI group during the study period.


CONCLUSIONS
The SEB technique with ropivacaine provides superior epidural block compared with an identical hourly dose administered as a continuous infusion.
Ueda
Kenichi
K
Department of Anesthesia, Kochi Medical School, Japan. uedak@gf6.so-net.ne.jp
Ueda
Wasa
W
Manabe
Masanobu
M
D000328:Adult; D000577:Amides / Q000008:administration & dosage*; D000767:Anesthesia, Epidural / Q000379:methods*; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D007260:Infusion Pumps; D008875:Middle Aged; D010149:Postoperative Pain / Q000188:drug therapy* / Q000517:prevention & control; D000077212:Ropivacaine
D000577:Amides; D000077212:Ropivacaine