Low dose ketamine given i.v. or by peritonsillar infiltration perioperatively provides efficient pain relief without side-effects in children undergoing adenotonsillectomy.

SIR IR-Thank you for giving us the opportunity to respond to the letter of Shah and Preciado. The effects of perioperative peritonsillar infiltration of drugs prior to tonsillectomy on postoperative analgesia have not been well evaluated. Apart from published case reports about the complications of peritonsillar space injections, there are also many studies in the literature reporting no complication related to injection of various drugs into the peritonsillar space for postoperative pain relief.In our article we did not imply that 1 ml is a small amount to inject into this space. There are several published articles, involving ting peritonsillar infiltration of various drugs with 1 ml to a maximum of 5 ml per tonsillar region in children. In our study we preferred the minimum volume which was 1 ml per side.Again in our article we did not suggest routine injection into the peritonsillar space. We compared the effects and results of i.v. and peritonsillar administration of ketamine on patients undergoing adenotonsillectomy. We found that both routes of administration of ketamine have similar effects on postoperative pain relief in children. Of course there could be serious complications of any procedure in inexperienced hands but we could not find any published material regarding complications such as pseudo aneurysms, thrombi, or mortality after injection into the peritonsillar space. In a recent publication, posttonsillectomy infiltration of 2 ml, 0.5 mgAEkg )1 of ketamine and 2 ml of saline into the tonsillar region in 60 children were compared (1) with the results being similar to ours. Moreover in that study (1) they compared ketamine infiltration with saline infiltration, which was lacking in our study and they found ketamine infiltration easy and effective for postoperative pain relief after tonsillectomy with no side effects.According to the power analysis in our study, 30 patients in each group would have an 80% power to detect a 20% difference in the OPS (Observational Pain Scores) between the placebo and the ketamine group. We also emphasized the mechanism of action of ketamine in the limitations of our study in our article.Our results showed that there were no differences between the i.v. ketamine and peritonsillar infiltration of ketamine groups in pain relief or side effects. That is why we did not suggest a preference of one method over the other. There are many a ways of administering ketamine as shown in previous studies (2,3). As there is a risk of an unexpected complication in any new technique, patients should be observed carefully for signs of complications after such procedures. In our study peritonsillar infiltration of the drug was performed by the same experienced surgeon in all cases. All patients were followed up for at least 48 h after the surgery via phone calls.Keeping in mind the possibility of complications especially after any kind of procedure applied in children, the safest and most reliable and effective treatment modality should always be preferred.D id em D al M D