Comparison of preoperative with postoperative topical lidocaine spray on pain after tonsillectomy.

Seventy-five children aged 4-6 years scheduled for tonsillectomy were randomly allocated to receive either topical tonsillar spray with 10% lidocaine 4 mg kg-1 3 minutes before surgical incision; identical tonsillar spray after both tonsils had been removed; or no topical spray (control group). There were significant differences in postoperative pain between the lidocaine groups and the control group at 0.5 and one hour after awaking (P < 0.05). Also in the lidocaine groups, consumption of paracetamol on the day of operation was less, and additional postoperative pethidine was not required. There were no significant differences between pre- and postoperative lidocaine groups in pain scores during the observation period but the use of pre-operative lidocaine tended to be associated with a more rapid return to calm wakefulness. Topical lidocaine seemed to have short-acting analgesic activity. The results of this study do not support the theory of pre-emptive analgesia.