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. CONCLUSION: 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.

Herbal and homeopathic medication use in pediatric surgical patients.

BACKGROUND: Patients who present for surgery may be using herbal or homeopathic preparations; adverse effects of some of these substances include bleeding, cardiovascular changes, and liver dysfunction. Little information is available on the frequency of use in the pediatric surgical population. METHODS: With institutional approval, a survey was conducted to assess the use of vitamins, nutritional supplements, or herbal or homeopathic preparations in children presenting for surgery in five geographically diverse centers in the USA. RESULTS: A total of 894 completed surveys showed that overall, 3.5% of pediatric surgical patients had been given herbal or homeopathic medications in the 2 weeks prior to surgery. Most substances were prescribed by parents. The use of these medications did not differ between children with coexisting diseases and those without; use was also not different among ethnic groups or by residence setting (city, suburban, rural). There was a significant difference between the west coast centers in the study compared with the rest of the country (7.5% of patients in Palo Alto, CA; 5.5% of patients in Seattle, WA; 1.5% of patients in Chicago, IL; and 1.9% in Virginia and Delaware used herbal or homeopathic remedies). The most prevalent substance given to children presenting for elective surgery was Echinacea. CONCLUSIONS: Herbal and homeopathic medications are used by a small percentage of pediatric patients presenting for elective pediatric surgery patients. Use of these substances should be addressed in the preoperative history.