RESUMO
OBJECTIVE: To evaluate different doses of dexmedetomidine for the prevention of emergence agitation in children undergoing adenotonsillectomy. METHOD: One hundred and thirty children aged 3-10 years scheduled for adenotonsillectomy were randomly assigned to two groups. Anesthesia was induced with 0.5 µg.kg-1 dexmedetomidine (DEX 0.5 group) or 1 µg.kg-1 dexmedetomidine (DEX 1 group) at the beginning of surgery. Observers who recorded the data in the postanesthesia care unit were blinded to the allocation. The primary outcome was the percentage of emergence agitation. The times to spontaneous breath, awake, extubate, and postanesthesia care unit stay were also recorded. RESULTS: One hundred twenty four children were randomized into two groups. Five children were excluded because of adverse events and dropout (DEX 0.5 group, n = 58; DEX 1 group, n = 62). No significant differences were noted in the percentage of emergence agitation between the two groups. The times to extubation (p = 0.003), awake, and postanesthesia care unit stay in DEX 0.5 group were shorter than those in DEX 1 group (p < 0.0001). There was no significant difference between the two groups in the time to spontaneous breath. Approximately 8% of patients in DEX 0.5 group and 18% patients in DEX 1 group presented low SpO2, showing a significant difference between the two groups (p = 0.043). CONCLUSIONS: A dose of 0.5 µg.kg-1 dexmedetomidine was equally effective as 1 µg.kg-1 dexmedetomidine in preventing emergence agitation. TRIAL REGISTRATION: The trial is currently completed recruitment, registered in ClinicalTrials.gov (ID:NCT03760809). Inclusion began on 4 January, 2019.