Comparison of Intranasal Dexmedetomidine and Oral Pentobarbital Sedation for Transthoracic Echocardiography in Infants and Toddlers: A Prospective, Randomized, Double-Blind Trial

BACKGROUND: Acquisition of transthoracic echocardiographic (TTEcho) images in children often requires sedation. The optimal sedative for TTEcho has not been determined. Children with congenital heart disease are repeatedly exposed to sedatives and anesthetics that may affect brain development. Dexmedetomidine, which in animals alters brain structure to a lesser degree, may offer advantages in this vulnerable population. METHODS: A prospective, randomized, double-blind trial enrolled 280 children 3-24 months of age undergoing outpatient TTEcho, comparing 2.5 µg·kg intranasal dexmedetomidine to 5 mg·kg oral pentobarbital. Rescue sedation, for both groups, was intranasal dexmedetomidine 1 µg·kg. The primary outcome was adequate sedation within 30 minutes without rescue sedation, assessed by blinded personnel. Secondary outcomes included number of sonographer pauses, image quality in relation to motion artifacts, and parental satisfaction. RESULTS: Success rates with a single dose were not different between sedation techniques; 85% in the pentobarbital group and 84% in the dexmedetomidine group (P = .8697). Median onset of adequate sedation was marginally faster with pentobarbital (16.5 [interquartile range, 13-21] vs 18 [16-23] minutes for dexmedetomidine [P = .0095]). Time from drug administration to discharge was not different (P = .8238) at 70.5 (64-83) minutes with pentobarbital and 70 (63-82) minutes with dexmedetomidine. Ninety-five percent of sedation failures with pentobarbital and 100% of dexmedetomidine failures had successful rescue sedation with intranasal dexmedetomidine. CONCLUSIONS: Intranasal dexmedetomidine was comparable to oral pentobarbital sedation for TTEcho sedation in infants and did not increase the risk of clinically important adverse events. Intranasal dexmedetomidine appears to be an effective "rescue" sedative for both failed pentobarbital and dexmedetomidine sedation. Dexmedetomidine could be a safer option for repeated sedation in children, but further studies are needed to assess long-term consequence of repeated sedation in this high-risk population.