The addition of adrenaline to thoracic epidural meperidine does not improve analgesia following thoracotomy

Abstract

Purpose: Patient-controlled epidural analgesia (PCEA) with meperidine provides effective analgesia following thoracotomy. Accumulation of normeperidine, a meperidine metabolite with neuroexcitatory effects, has led to recommendations to limit the use of meperidine postoperatively. The purpose of this study was to determine if the addition of adrenaline to PCEA meperidine decreased meperidine consumption, reduced serum normeperidine levels, and improved analgesia following thoracotomy.Methods: Following Research Ethics approval consenting patients were randomly assigned to PCEA with either meperidine (2 mg·mL -1 ) + adrenaline (2 µg·mL -1 ) or meperidine alone (2 mg·mL -1 ). All patients received a standardized anesthetic and similar perioperative care. Visual analogue pain scores (at rest and with activity), quality of recovery (QoR) scores, and side effects were documented six, 24, and 48 hr postoperatively. Serum levels of meperidine and normeperidine were measured at the same time points.Results: Forty-six patients completed the study protocol. Meperidine consumption (mean ± SD) was similar in the meperidine + adrenaline and the meperidine groups (601 ± 211 mg vs 580 ± 211 mg over 48 hr, respectively; P = 0.744). Serum meperidine levels were similar at all study time points. Serum normeperidine was not detected in any sample. Pain scores, QoR scores, and adverse events were comparable in both study groups. Conclusion:The addition of adrenaline did not influence PCEA meperidine consumption, analgesia outcomes, or QoR. Normeperidine did not accumulate in patients of either study group during the 48-hr study period. Meperidine for patientcontrolled epidural analgesia, with or without adrenaline, provides effective post-thoracotomy analgesia in selected patients.