Intraoperative clonidine for prevention of postoperative agitation in children anaesthetised with sevoflurane (PREVENT AGITATION): a randomised, placebo-controlled, double-blind trial.

Background: Postoperative agitation is a frequent and stressful condition for a child, their family, and their health-care providers, and prevention would be of benefit. We aimed to assess the effects of intravenous clonidine administered intraoperatively on the incidence of postoperative agitation, pain, and adverse events.

Methods: We did this randomised, placebo-controlled, double-blind trial (PREVENT AGITATION) at one tertiary-level hospital and two urban-district hospitals in Denmark. Children aged 1-5 years, with an American Society of Anesthesiologists physical classification score of 1-2, who were scheduled for anaesthesia with sevoflurane and fentanyl were randomly assigned (1:1) in blocks of ten by computer-generated centralised randomisation, stratified by age (<2 years or ≥2 years) and site, to receive either intravenous clonidine 3 μg/kg or an equal quantity of isotonic saline in identical vials, administered around 20 min before the completion of surgery. Data were collected from the postoperative care unit (24 h) and at follow-up (30 days). Our primary outcome was the proportion of patients with one or more episodes of postoperative agitation, measured every 15 min in the postoperative care unit (POCU) with the four-point Watcha scale (ie, Watcha >2). We analysed by intention to treat. The trial is registered with ClinicalTrials.gov (number NCT02361476).

Findings: Between January and December, 2015, of the 379 eligible children, we randomly assigned 191 to receive clonidine treatment and 188 to receive placebo; 75 were girls (20%). Nine were excluded from the primary outcome analysis because of missing data points. 46 (25%) of 187 clonidine participants compared with 86 (47%) of 183 placebo participants had one or more episodes of postoperative agitation (Watcha score >2; relative risk 0·56, 95% CI 0·43-0·73; p<0·0001). 30 (20%) of 150 boys in the clonidine group were agitated compared with 69 (47%) of 147 boys in the placebo group (0·43, 0·30-0·61; p<0·0001). The observed effect was not significant in girls. Incidence of adverse events was similar in the clonidine and placebo groups.

Interpretation: On the basis of our results, clonidine might be used to safely prevent postoperative agitation in boys anaesthetised with sevoflurane.

Funding: Danish Society of Anaesthesia and Intensive Care.