The effects of incisional bupivacaine infusions on postoperative opioid consumption and pain scores after total abdominal hysterectomy

Abstract

Background: The aim of this study was to determine opioid requirements and pain intensity scores in patients after a total abdominal hysterectomy (TAH) administered with a bupivacaine infusion for a 30-hour period, and then to compare the data with that of a control group. Method: This was a prospective, parallel, single-blinded randomised trial which took place at the Rahima Moosa Mother and Child Hospital, Johannesburg. Thirty-six consenting patients, who underwent a TAH, were randomised to either having a 0.39% bupivacaine infusion in the incisional site or not. Morphine was administered via a patient-controlled analgesia pump (PCA) for rescue analgesia. Dynamic, static and worst pain scores were assessed one, six and 30 hours after surgery by using a visual analogue scale (VAS). Morphine consumption was recorded at set intervals. Results: There were statistically significant differences between the two groups’ dynamic VAS scores in the first hour and at 24 hours and 30 hours; in the static VAS score in the first hour; and in the VAS scores for the worst pain experienced since the patients were last seen in the first hour and six hours after the operation. There was no statistical difference between the two groups’ opioid consumption at all set observation points. Conclusion: The opioid requirements of the two groups were comparable, although participants who had the bupivacaine infusion experienced reduced pain intensity which lasted until six hours postoperatively, and also had reduced pain intensity when moving around 30 hours after the operation.