Effect of pre- vs postoperative tonsillar infiltration with local anesthetics on postoperative pain after tonsillectomy

Background: Since pre-incisional peritonsillar infiltrations of local anesthetic solutions have been suggested to reduce postoperative pain after tonsillectomy, we compared the efficacy of either pre- or postoperative local anesthetic infiltration upon post-tonsillectomy pain. Methods: After the induction of general anesthesia, 68 consecutive healthy patients, ranging in age from 8 to 65 years, were randomly allocated to either receive peritonsillar infiltration with 0.25% bupivacaine (group 1) or normal saline (group 2) before incision. A third group (group 3) had their peritonsillar region infiltrated with 0.25% bupivacaine after the completion of surgery but before the patients were awakened from anesthesia. All the patients were treated in the same way in the postoperative period: NSAIDs were given intravenously to adults and rectally to children. Acetaminophen was given intravenously or rectally (children aged <15 yr) if additional analgesic support was requested by the patient. Additional acetaminophen consumption was recorded daily. Pain scores were assessed on every patient with the use of a visual analogue scale (VAS) at rest, 1, 5, 9, 13, 17, 21 and 36 h after surgery, and also on swallowing during the first postoperative day. Results: Global VAS pain scores were lower in the groups treated with bupivacaine infiltration during the first 24 h after surgery (P<0.05). Supplementary analgesic consumption was lower in group 3 than in group 2 during the 0-9 h interval immediately following surgery (P<0.05). There were no statistically significant differences for any other parameters between the 3 groups. Conclusion: These results suggest that the timing of peritonsillar infiltration with bupivacaine is not of clinical importance and does not affect the quality of postoperative analgesia in patients undergoing tonsillectomy. (C) Acta Anaesthesiologica Scandinavica 40 (1996)