Effect of dexamethasone on nausea, vomiting, and pain in paediatric tonsillectomy.

BACKGROUND The efficacy of dexamethasone (DEX) to reduce morbidity after paediatric tonsillectomy remains controversial. We evaluated the effect of 0.15 and 0.5 mg kg(-1) DEX on the incidence of postoperative nausea and vomiting (PONV) and on pain intensity after paediatric tonsillectomy. METHODS A total of 147 children aged 2-8 yr undergoing elective tonsillectomy were included in this prospective randomized double-blind study. At the induction of anaesthesia, subjects received 0.15 mg kg(-1) (DEX 0.15), 0.5 mg kg(-1) (DEX 0.5) DEX, or an equivalent volume of saline solution (placebo). Anaesthetic and surgical techniques were standardized. The incidence of PONV and the need for anti-emetic drugs and additional analgesia (tramadol and/or morphine) were recorded. Postoperative pain was assessed using the Children's Hospital of Eastern Ontario Pain Scale, the visual analogue scale, and the postoperative pain measure for parents. RESULTS The incidence of early PONV (primary outcome variable) was lower in both DEX groups (DEX 0.15: 21%; DEX 0.5: 22%; placebo: 49%; P=0.001). The incidence of severe pain was reduced in the DEX groups on the second postoperative day (DEX 0.15: 20%; DEX 0.5: 5%; placebo: 47%; P<0.001). The study was not powered to assess a difference between the two DEX dose groups. CONCLUSIONS A single i.v. injection of DEX at the induction of anaesthesia was effective in reducing the incidence of early and late PONV and the level of pain on the second postoperative day. A 0.15 mg kg(-1) DEX dose appeared to be as effective as a 0.5 mg kg(-1) dose to reduce the incidence of PONV.