Background
The aim of this study was to investigate the effects of a multimodal analgesic regimen, including intravenous ketamine and peritonsillar infiltration of bupivacaine, on post-tonsillectomy pain in children.
Material and Method
Ninety children aged 2-12 years, undergoing tonsillectomy, were enrolled in this randomized, controlled and double-blinded study. Group I (n=30) received intravenous and peritonsillar saline, group II (n=30) received intravenous saline and peritonsillar bupivacaine, and group III (n=30) received intravenous 0.5 mg/kg ketamine and peritonsillar 0.25% bupivacaine (3-5 ml per tonsil). Pain was evaluated using a modified Children's Hospital of Eastern Ontario Pain Scale (mCHEOPS) recorded 15 min and 1, 4, 12, 16, and 24 h postoperatively.
Results
No difference was found in the demographic data among the groups. Group I patients who received intravenous and peritonsillar saline solution as placebo had higher pain scores at 15th min, and 1st and 4th h than group II, and at all time intervals, than group III (P<0.05). Patients in group III also had significantly lower pain scores than group II at all time intervals except at 15th min (P<0.05). Analgesic requirements and the time to first analgesia were also significantly (P<0.05) better in the ketamine group.
Conclusions
Intravenous ketamine and peritonsillar infiltration with bupivacaine are safe and effective as part of a multimodal regime in reducing post-tonsillectomy pain.

Keywords: Pain Measurement, Ketamine - therapeutic use, Injections, Intravenous, Combined Modality Therapy, Demography, Child, Preschool, Child, Bupivacaine - therapeutic use, Analgesics - therapeutic use, Adolescent, Pain, Postoperative - drug therapy, Tonsillectomy