title: Dosing and efficacy of intranasal dexmedetomidine sedation for pediatric transthoracic echocardiography: a retrospective study.
abstract: OBJECTIVE
  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.
  
  
  CONCLUSIONS
  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(-1)administered under the supervision of a pediatric cardiac anesthesiologist.
authors.affiliation: Department of Anesthesiology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue MLC2001, Cincinnati, OH, 45229, USA. Jeff.Miller@cchmc.org.
authors.forename: Jeffrey W
authors.initials: JW
authors.lastname: Miller
authors.affiliation: Department of Cardiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
authors.forename: Allison A
authors.initials: AA
authors.lastname: Divanovic
authors.affiliation: Division of Biostatistics & Epidemiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
authors.forename: Md M
authors.initials: MM
authors.lastname: Hossain
authors.affiliation: Department of Anesthesiology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue MLC2001, Cincinnati, OH, 45229, USA.
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: Mahmoud
authors.affiliation: Department of Anesthesiology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue MLC2001, Cincinnati, OH, 45229, USA.
authors.forename: Andreas W
authors.initials: AW
authors.lastname: Loepke
mesh_terms: D000281:Administration, Intranasal; D020927:Dexmedetomidine / Q000008:administration & dosage* / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D004452:Echocardiography; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage* / Q000627:therapeutic use; D007223:Infant; D008297:Male; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D006993:Hypnotics and Sedatives; D020927:Dexmedetomidine