ObjectiveTo investigate and compare the effectiveness of preincisional peritonsillar infiltration of ketamine and tramadol for post-operative pain on children following adenotonsillectomy. Study designProspective randomized double blind controlled study. MethodsSeventy-five children aged 3–10 years undergoing adenotonsillectomy were included in study. Patients received injections in peritonsillar fossa of tramadol (2mg/kg-2ml), ketamine (0.5mg/kg-2ml) or 2ml serum physiologic. During operation heart rate, oxygen saturation, average mean blood pressures were recorded in every 5min. Operation, anesthesia and the time that Alderete scores 9–10, patient satisfaction, analgesic requirements were recorded. Postoperatively nausea, vomiting, sedation, dysphagia, bleeding scores were recorded at 0, 10, 30, 60min and 2, 4, 8, 12, 18, 24h postoperatively. Pain was evaluated using modified Children's Hospital of Eastern Ontario Pain Scale (mCHEOPS) at fixed intervals after the procedure (15min and 1, 4, 12, 16, and 24h postoperatively). ResultsThe recordings of heart rate, mean arterial pressure, nausea, vomiting, sedation and bleeding scores were similar in all groups (p>0.05). The mCHEOPS scores at 10min, 30min, 1h, 8h were significantly lower in both tramadol and ketamine group when compared with control (p<0.05). Use of additional analgesia at 10min and 18h were higher in control group than ketamine, tramadol group (p<0.05). Dysphagia scores were significantly lower for both ketamine and tramadol group when compared with control group (p<0.05). mCHEOPS, additional analgesia, dysphagia, patient satisfaction scores were similar in tramadol, ketamine groups (p>0.05). ConclusionsPreincisional injection of ketamine and tramadol prior to tonsillectomy is safe, effective method and equivalent for post-tonsillectomy pain, patient satisfaction, postoperative nausea, vomiting, dysphagia.