Dexmedetomidine-related atrial standstill and loss of capture in a pediatric patient after congenital heart surgery.
OBJECTIVE
Dexmedetomidine (DEX; Precedex) is an alpha-2 adrenergic receptor agonist that produces anxiolysis and sleep-like sedation without narcosis or respiratory depression and has relatively few cardiovascular side effects. Given its favorable sedative properties combined with its limited effects on hemodynamic and respiratory function, it is widely used in pediatric intensive care and anesthesia settings.


METHODS
Case report.


METHODS
Pediatric intensive care unit.


METHODS
A three-yr-old girl was admitted after mitral valve replacement for persistent severe mitral insufficiency. Her prior history was significant for tetralogy of Fallot which was repaired at nine months of age. A year later the patient developed mitral and tricuspid valve insufficiency and subsequently underwent mitral and tricuspid valve repair, pulmonary valve replacement, and a maze procedure (the latter was performed for persistent atrial flutter). Following that operation she developed sinus node dysfunction and had a permanent epicardial dual-chamber pacemaker implanted. Due to remaining severe mitral insufficiency the patient had increasing pulmonary symptoms, necessitating the most recent surgery to replace her mitral valve.


METHODS
On postoperative day two the patient was hemodynamically stable and weaning off mechanical ventilation. Tracheal extubation was anticipated to occur within the next 24 hrs. A DEX infusion of 0.6 mcg/kg/hr was initiated. A pacemaker interrogation performed on postoperative day three, 21 hrs after the initiation of DEX, revealed unsuccessful atrial capture.


RESULTS
Dexmedetomidine was subsequently discontinued and the patient's pacemaker was reinterrogated. The interrogation findings were similar to those seen prior to the initiation of DEX.


CONCLUSIONS
As a result of these findings, caution is warranted in the administration of DEX to patients with predisposing conduction abnormalities and patients who are pacemaker-dependent.
Rady Children's Hospital, San Diego, CA, USA. sshepard@rchsd.org
Suzanne M
SM
Shepard
Shai
S
Tejman-Yarden
Sandeep
S
Khanna
Christopher K
CK
Davis
Anjan S
AS
Batra
D054537:Atrioventricular Block / Q000139:chemically induced* / Q000628:therapy; D002675:Child, Preschool; D016292:Procedural Sedation / Q000009:adverse effects / Q000379:methods; D020927:Dexmedetomidine / Q000008:administration & dosage / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria / Q000187:drug effects; D006330:Heart Defects, Congenital / Q000175:diagnosis / Q000601:surgery; D019918:Heart Valve Prosthesis Implantation / Q000379:methods*; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000009:adverse effects*; D015278:Intensive Care Units, Pediatric; D008944:Mitral Valve Insufficiency / Q000175:diagnosis / Q000601:surgery*; D010138:Pacemaker, Artificial; D011182:Postoperative Care / Q000379:methods; D018570:Risk Assessment; D013997:Time Factors; D016896:Treatment Outcome
D006993:Hypnotics and Sedatives; D020927:Dexmedetomidine