Perioperative dexmedetomidine compared to midazolam in children undergoing open-heart surgery: A pilot randomised controlled trial

OBJECTIVE: There is a need for evidence on the best sedative agents in children undergoing open heart surgery for congenital heart disease. This study aimed to evaluate the feasibility and safety of dexmedetomidine in this group compared with midazolam. DESIGN: Double blinded, pilot randomized controlled trial. SETTING: Cardiac operating theatre and paediatric intensive care unit in Brisbane, Australia. PARTICIPANTS: Infants (≤12 months of age) undergoing their first surgical repair of a congenital heart defect. INTERVENTIONS: Dexmedetomidine (up to 1.0mcg/kg/hr) versus midazolam (up to 80mcg/kg/hr), commenced in the cardiac operating theatre prior to surgery. MAIN OUTCOME MEASURES: The primary outcome was the time spent in light sedation (Sedation Behavior Scale [SBS] -1 to +1); Co-primary feasibility outcome was recruitment, retention and protocol adherence. Secondary outcomes were use of supplemental sedatives, ventilator free days, delirium, vasoactive drug support, and adverse events. Neurodevelopment and health-related quality of life (HRQoL) were assessed at 12 months post-surgery. RESULTS: Sixty-six participants were recruited. The number of SBS scores in the light sedation range were greater in the dexmedetomidine group at 24 hours, 48 hours, and overall study duration (0-14 days) versus the midazolam group (24hr: 76/170 [45%] vs 60/178 [34%], aOR 4.14 [95% CI 0.48, 35.92]; 48hr: 154/298 [52%] vs 122/314 [39%], aOR 6.95 [95% CI 0.77, 63.13]; 0-14 days: 597/831 [72%] vs 527/939 [56%], aOR 3.93 [95% CI 0.62, 25.03]). Feasibility was established with no withdrawals or loss to follow-up at 14 days and minimal protocol deviations. There were no differences between the groups relating to clinical, safety, neurodevelopment or HRQoL outcomes. CONCLUSIONS: The use of dexmedetomidine was associated with more time spent in light sedation when compared with midazolam. The feasibility of conducting a blinded RCT of midazolam and dexmedetomidine in children undergoing open heart surgery was also established. The findings justify further investigation in a larger trial. CLINICAL TRIAL REGISTRATION: ACTRN12615001304527.