Preoperative sedation in children with congenital heart disease: 50% and 95% effective doses, hemodynamic effects, and safety of intranasal dexmedetomidine

Study objective: To determine the 50% and 95% effective doses (ED50 and ED95, respectively), hemodynamic effects, and safety of intranasal dexmedetomidine for preoperative sedation in pediatric patients with congenital heart disease (CHD) with a left-to-right shunt. Design: Double-blind sequential allocation trial. Setting: Pediatric preoperative waiting area. Patients: 86 pediatric patients ASA physical status II-III scheduled for cardiac surgery, agedl-month to 6-yearsold with left-to-right type CHD. Interventions: Children were divided into three groups according to age: infants (1 month-1 year), toddlers (1-3 years), and preschoolers (3-6 years). The first patient in all groups received intranasal dexmedetomidine (2 mu g/kg), using the up-and-down Dixon method, and the and the next patient's dose was dependent on the previous patient's response. Measurements: Assessment using the Modified Observer's Assessment of Alertness/Sedation Scale and the Mask Acceptance Scale was performed before and every 5 min after treatment. Pulse oxygen saturation and heart rate were recorded at baseline, at 10-min intervals, and after admission to the operating room. Systolic pulmonary artery pressure was measured before anesthesia induction. Main results: The respective ED50 (95% confidence interval [CI]) and ED 95 (95% CI) values for preoperative sedation using intranasally administered dexmedetomidine were 3.1 (2.8-3.3) and 3.5 (3.3-4.0) mu g/kg for infants; 3.4 (3.2-3.6) and 3.9 (3.7-4.4) mu g/kg for toddlers; and 2.4 (2.2-2.6) and 2.9 (2.6-3.3) mu g/kg for preschoolers. ED 50 was lower for preschoolers than for toddlers (p < 0.001) and infants (p = 0.044). No obvious difference in ED50 was found between infants and toddlers. There was no significant difference in sedation onset time among the groups, and no adverse events were observed during sedation in all patients. Conclusions: Intranasal dexmedetomidine can be safety used for preoperative sedation in children with CHD and is effective for sedation when dosed appropriately.