Epidural ropivacaine with fentanyl following major gynaecological surgery:the effect of volume and concentration on pain relief and motor impairment

In a prospective, randomized, double-blind study, 40 patients undergoing gy naecological oncology surgery received either 0.1% ropivacaine with fentany l I mu g ml(-1) or 0.2% ropivacaine with fentanyl 2 mu g ml(-1). A PCEA pum p was set to deliver ropivacaine 8 mg with fentanyl 8 mu g with each succes sful demand and a lockout period of 15 min without background infusion. Pat ients were observed for rest and activity pain VAS, side effect incidence, peak expiratory flow rate (PEFR), leg strength, sensory block to cold and p inprick, and PCEA usage into the second postoperative day. Passive and acti ve pain scores for both groups were both satisfactory and comparable for th e duration of the study. There were no differences between groups with rega rd to side effects. There was a 24% increase in total drug used in the high -concentration/ low-volume group (P<0.05). The study demonstrated that PCEA ropivacaine with fentanyl is an effective means of postoperative analgesia for this patient population. Reduced drug consumption with high-volume/low -concentration solution confirms similar findings by other investigators us ing alternate local anaesthetic agents, and suggests that the therapeutic r atio of ropivacaine is widened if a low-concentration/high-volume solution is used.