Wound infiltration with lidocaine prolongs postoperative analgesia after haemorrhoidectomy with spinal anaesthesia

Purpose: There are few clinical data examining whether sensitization of peripheral nerves contributes to postoperative pain when the entry of noxious impulses to the central nervous system is blocked. We hypothesized that wound infiltration with lidocaine would provide better postoperative analgesia than with normal saline following haemorrhoidectomy with spinal blockade. Methods: In a randomized, placebo-controlled blinded study, 168 adults undergoing haemorrhoidectomy were allocated to two groups. In Group L (n = 88) local infiltration was provided with lidocaine 1% and in Group S (n = 80) with normal saline. Following spinal anaesthesia with lidocaine 3%, the surgeon infiltrated 15 ml of either infiltration solution to the surgical area. Postoperative analgesia was obtained by continuous epidural administration of 90 mg eptazocine in normal saline for 48 hr. Supplemental analgesics were given on request. Postoperative pain control was assessed at rest and during coughing with a 10 cm VAS on the 1st, 2nd, and 3rd postoperative days (POD). Results: The VAS scores at rest in Group L were lower than those in Group S throughout the postoperative period. During coughing, VAS scores in Group S were increased on the 3rd postoperative day, while those in Group L remained constant (4.42 ± 0.27 vs 3.14 ± 0.28, P < 0.05). Fewer patients in Group L than in Group S required supplemental analgesics. Conclusion: Preoperative lidocaine infiltration to the surgical area provided prolonged postoperative analgesia in patients receiving haemorrhoidectomy with spinal anaesthesia.