NEW YORK (Reuters Health) - In children undergoing tonsillectomy, preoperative injection of lidocaine plus bupivacaine, with or without clonidine, does not reduce the use of analgesics in the following week, according to a report in the Archives of Otolaryngology--Head and Neck Surgery, published online March 21.

Based on the results, the authors advise, “We do not recommend pretonsillectomy injection for reducing morbidity in pediatric tonsillectomy patients.”

While the benefits of tonsillectomy are well known, substantial morbidity and pain occurs during recovery, Dr. Jonathan R. Moss, with Vanderbilt University in Nashville, Tennessee, and colleagues comment. Recent studies have indicated that early and late post-tonsillectomy pain may be reduced by preoperative injections of clonidine and local amide anesthetics.

“Our study was designed to validate and expand on these findings by using short-acting (lidocaine hydrochloride) and long-acting (bupivacaine hydrochloride) amide local anesthetics with and without clonidine hydrochloride to examine their effects on decreasing post-tonsillectomy morbidity,” they explain.

The study involved 120 children who were randomized to injections of saline, lidocaine 1% and bupivacaine 0.5%, or lidocaine plus bupivacaine plus clonidine 25 mcg, into the peritonsillar mucosa on each side. Tonsillectomy using monopolar electrocautery began 5 minutes after injection.

The median cumulative pain medication use in the following 7 days did not differ significantly between the three groups, according to the report. Specifically, the median number of doses of acetaminophen/hydrocodone (0.15 mg/kg/dose) was 14.0 for lidocaine plus bupivacaine plus clonidine, and 12.0 in both the lidocaine-plus-bupivacaine group and the saline group.

The pain scores measured by visual analog scale did not differ at discharge or on most postoperative days. However, on postop day 3, the placebo group actually had lower scores than patients given lidocaine plus bupivacaine plus clonidine (p=0.04).

Furthermore, the investigators report, the placebo group was significantly more likely to have an advanced diet on the first postop day than the lidocaine/bupivacaine/clonidine group (p=0.04).

The authors comment that the results were unexpected, and this prompted a review to confirm the integrity of randomization -- which was found to be accurate.

Consequently, they write, “Based on the results of our study, we have changed the practice at our institution to no longer inject local anesthetics during tonsillectomy.”

Arch Otolaryngol Head Neck Surg 2011.