POSTOPERATIVE PAIN RELIEF BY TOPICAL LIDOCAINE IN THE SURGICAL-WOUND OF HYSTERECTOMIZED PATIENTS

Background: To improve postoperative analgesia, local anesthetics have been administered perioperatively as infiltration or as aerosol in th e surgical area. A previous study showed good analgesic effects by top ical lidocaine in the wound in minor extraabdominal surgery (herniorra phy), while the same treatment in minor lower laparothomies did not im prove postoperative analgesia. The present study investigated the effe ct of topical wound anesthesia using lidocaine aerosol on postoperativ e pain following major lower abdominal surgery. Methods: Postoperative pain and analgesic requirements were studied in a double-blind random ized trial including 30 hysterectomized patients. Patients were random ized to receive single wound treatment either with lidocaine aerosol 5 00 mg (100 mg/ml; Xylocain(R) aerosol, ASTRA, Sweden) (n=15) or placeb o aerosol (n=15). Postoperative pain was evaluated by visual analogue scale (VAS). Requirements of opiate analgesics (buprenorphine) after s urgery were monitored. Results: Lidocaine aerosol induced a significan tly (P<0.001) better analgesia at rest (VAS) and a significant (P<0.00 1) reduction in postoperative requirements of buprenorphine during the first 24 hours after surgery compared to placebo aerosol. Differences between the groups in pain scores (VAS) and buprenorphine requirement s during the second postoperative day were not significant. Mean pain scores upon mobilization 24 h after surgery were significantly lower i n the group receiving Lidocaine aerosol (P<0.05). The plasma lidocaine concentration 4 h after the administration of lidocaine was well belo w toxic level and plasma lidocaine was detectable 48 h postoperatively . No drug-related side effects were reported. Conclusion: A single dos e of Lidocaine aerosol topically administered in the surgical wound of hysterectomy patients improved analgesia during the first postoperati ve day with minimal risk of side effects.