The effects of dexmedetomidine on cardiac electrophysiology in children.
BACKGROUND
Dexmedetomidine (DEX) is an alpha2-adrenergic agonist that is approved by the Food and Drug Administration for short-term (<24 h) sedation in adults. It is not approved for use in children. Nevertheless, the use of DEX for sedation and anesthesia in infants and children appears to be increasing. There are some concerns regarding the hemodynamic effects of the drug, including bradycardia, hypertension, and hypotension. No data regarding the effects of DEX on the cardiac conduction system are available. We therefore aimed to characterize the effects of DEX on cardiac conduction in pediatric patients.


METHODS
Twelve children between the ages of 5 and 17 yr undergoing electrophysiology study and ablation of supraventricular accessory pathways had hemodynamic and cardiac electrophysiologic variables measured before and during administration of DEX (1 microg/kg IV over 10 min followed by a 10-min continuous infusion of 0.7 microg x kg(-1) x h(-1)).


RESULTS
Heart rate decreased while arterial blood pressure increased significantly after DEX administration. Sinus node function was significantly affected, as evidenced by an increase in sinus cycle length and sinus node recovery time. Atrioventricular nodal function was also depressed, as evidenced by Wenckeback cycle length prolongation and prolongation of PR interval.


CONCLUSIONS
DEX significantly depressed sinus and atrioventricular nodal function in pediatric patients. Heart rate decreased and arterial blood pressure increased during administration of DEX. The use of DEX may not be desirable during electrophysiology study and may be associated with adverse effects in patients at risk for bradycardia or atrioventricular nodal block.
Hammer
Gregory B
GB
Department of Anesthesiology, Lucile Packard Children's Hospital and Stanford University School of Medicine, Stanford, California, USA. ham@stanford.edu
Drover
David R
DR
Cao
Hong
H
Jackson
Ethan
E
Williams
Glyn D
GD
Ramamoorthy
Chandra
C
Van Hare
George F
GF
Niksch
Alisa
A
Dubin
Anne M
AM
D000293:Adolescent; D000316:Adrenergic alpha-Agonists / Q000008:administration & dosage / Q000009:adverse effects*; D001283:Atrioventricular Node / Q000187:drug effects / Q000503:physiopathology / Q000601:surgery; D001794:Blood Pressure / Q000187:drug effects; D017115:Catheter Ablation; D002648:Child; D020927:Dexmedetomidine / Q000008:administration & dosage / Q000009:adverse effects*; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006329:Heart Conduction System / Q000187:drug effects* / Q000503:physiopathology / Q000601:surgery; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000009:adverse effects*; D007262:Infusions, Intravenous; D008297:Male; D015656:Respiratory Mechanics / Q000187:drug effects; D012849:Sinoatrial Node / Q000187:drug effects / Q000503:physiopathology / Q000601:surgery; D013617:Tachycardia, Supraventricular / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery; D016896:Treatment Outcome
D000316:Adrenergic alpha-Agonists; D006993:Hypnotics and Sedatives; D020927:Dexmedetomidine