Comparison of different bolus volume of the demand dose in a patient-controlled epidural analgesia after gastrectomy

Abstract

We investigated whether patient-controlled epidural analgesia (PCEA) with programmable maximal diluted bolus volume of bupivacaine plus fentanyl mixture has clinical advantages compared with an equivalent-dose, of an undiluted minimal mixture after gastrectomy. We randomly allocated 40 patients under general anesthesia to two groups in a randomized, double-blind study: one received a 9.9ml incremental bolus of diluted solution containing 0.051% bupivacaine and 2.53μg/ml fentanyl, and the other received a 2.5ml incremental bolus of a solution of 0.2% bupivacaine and 10μg/ml fentanyl with programmable maximal volume. We assessed analgesic efficacy and side effects. The number of deliveries for each 6h interval, the hourly drug consumption during the 48h postoperative period, and the VAS pain scales did not significantly differ between the two groups. The incidence of pruritus was significantly higher (p=0.039) in the 9.9ml group than in the 2.5ml group. The maximal diluted bolus volume of bupivacaine 5mg and fentanyl 25μg has no clinical advantages and produced a minor side effect in this post-gastrectomy PCEA regimen.