Intranasal dexmedetomidine versus oral midazolam premedication to prevent emergence delirium in children undergoing strabismus surgery A randomised controlled trial

BACKGROUND Dexmedetomidine is being used increasingly as a premedicant in the paediatric population. However, the effectiveness of pre-operative intranasal dexmedetomidine premedication, compared with oral midazolam, for emergence delirium is not well characterised. OBJECTIVE To identify the effectiveness of pre-operative intranasal dexmedetomidine for emergence delirium in the paediatric patient population following general anaesthesia. DESIGN A prospective, randomised, double-blind, parallel-group, placebo-controlled trial. SETTING Single university teaching hospital, from September 2013 to August 2014. PATIENTS One hundred and fifty-six patients undergoing anaesthesia for strabismus surgery were included in the study. INTERVENTION Patients were randomised in a 1 : 1 : 1 ratio to receive premedication with intranasal dexmedetomidine 2 mu g kg(-1) (the dexmedetomidine group), oral midazolam 0.5 mg kg(-1) (the midazolam group), or 0.9% saline (the placebo group). MAIN OUTCOME MEASURES The primary outcome was the incidence of emergence delirium assessed by the Paediatric Anaesthesia Emergence Delirium scale. Secondary outcomes included the quality of the inhalational induction, emergence time, postoperative pain intensity, length of stay in the postanaesthesia care unit, the incidence of postoperative nausea or vomiting (PONV) and parents' satisfaction. RESULTS The incidence of emergence delirium was lower in patients given dexmedetomidine compared with that in patients given midazolam (11.5 versus 44%, relative risk = 0.262, 95% confidence interval 0.116 to 0.592) or 0.9% saline (11.5 versus 49%, relative risk = 0.235, 95% confidence interval 0.105 to 0.525). Likewise, the incidence of PONV was lower in the dexmedetomidine group (3.8%) than that in the midazolam (22%; P = 0.006) or placebo (29.4%; P < 0.001) groups. However, there was no difference among the groups concerning postoperative pain scores and length of postanaesthesia care unit stay. CONCLUSION In paediatric patients undergoing strabismus surgery intranasal dexmedetomidine 2 mu g kg(-1) premedication decreases the incidence of emergence delirium and PONV, and improves parents' satisfaction compared with oral midazolam.