The efficacy of intravenous or peritonsillar infiltration of ketamine for postoperative pain relief in children following adenotonsillectomy.

BACKGROUND: A few previous studies have suggested the efficacy of i.v. ketamine for postoperative pain relief in children after adenotonsillectomy, but none has investigated the efficacy of peritonsillar infiltration of ketamine in these children.

METHODS: This randomized, placebo-controlled study evaluated the effects of peritonsillar infiltration of ketamine in children undergoing adenotonsillectomy. Ninety ASA I-II children were randomized three groups of 30 each. Group I received: 2 ml i.v. saline, group II received i.v. ketamine (0.5 mgxkg(-1)) and group III received a local peritonsillar infiltration of ketamine (0.5 mgxkg(-1)). All medications were 2 ml in volume which was applied 1 ml per tonsil 3 min prior to tonsillectomy. Modified Hannallah pain scale [observational pain scores (OPS)], nausea, vomiting, bleeding, rescue analgesia, sedation and Aldrete scores were recorded at first, 15th, 30th and 60th min postoperatively. Patients were interviewed on the day after surgery to assess the postoperative pain, nightmares, hallucinations, vomiting and bleeding.

RESULTS: Group I had higher OPS scores than group II and group III. Group II and group III had comparable scores, which were not statistically significant (P > 0.05). Group II had higher sedation score at 15th min (P = 0.015). Thirty-two children, 19 of whom were in group I had rescue analgesia in postanesthesia care unit (P < 0.05) and the time to first analgesic requirement was significantly shorter in group I than the other groups (P = 0.006). Group II and group III also had less pain than group I at home (P = 0.023).

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