Dosing and efficacy of intranasal dexmedetomidine sedation for pediatric transthoracic echocardiography: a retrospective study

Abstract

Purpose We designed this retrospective observational study on the use of α₂-agonist dexmedetomidine to determine the optimum intranasal dose to achieve sedation for pediatric transthoracic echocardiography and to identify any dose-related adverse effects. Methods Outpatient children aged three months to three years with diverse diagnoses of congenital heart disease, including cyanotic cardiac defects, underwent transthoracic echocardiography under dexmedetomidine sedation. Aerosolized intranasal dexmedetomidine was administered with initial doses ranging from 1-3 µg·kg⁻¹. A rescue dose of 1 µg·kg⁻¹ was administered if adequate sedation was not achieved within 45 min following the first dose. The primary study outcome was the achievement of adequate sedation to allow transthoracic echocardiography (TTE) scanning, including subxiphoid and suprasternal probe manipulation. Results Sedation with intranasal dexmedetomidine for transthoracic echocardiography was successful in 62 of the 63 (98%) patients studied, with an intranasal rescue dose required in 13 (21%) patients. Intranasal doses of dexmedetomidine 2.5-3.0 µg·kg⁻¹ were required for tolerating TTE probe placement, including subxiphoid and suprasternal manipulation, with minimal response and a 90% success rate. Excluding patients who required a second dose of dexmedetomidine, the mean (standard deviation) time from administration to achieving such sedation (onset time) was 26 (8) min for low-dose (1-2 µg·kg⁻¹) dexmedetomidine and 28 (8) min for moderate-dose (2.5-3.0 µg·kg⁻¹) dexmedetomidine (P = 0.33). Time from administration of low-dose dexmedetomidine to discharge, including TTE scan time, was 80 (14) min, and it increased with moderate-dose dexmedetomidine to 91 (22) min (P = 0.05). Mild to moderate bradycardia and hypotension were observed, but no interventions were required. Conclusion We found that aerosolized intranasal dexmedetomidine offers satisfactory conditions for TTE in children three months to three years of age with an optimal dose of 2.5-3.0 µg·kg⁻¹administered under the supervision of a pediatric cardiac anesthesiologist.