title: Oral atropine premedication in infants attenuates cardiovascular depression during halothane anesthesia.
abstract: The efficacy of oral atropine premedication in attenuation of the cardiovascular depression associated with halothane anesthesia has not been previously evaluated. A solution containing either oral atropine 0.04 mg/kg (HI), 0.02 mg/kg (LO), or a placebo (NO) was randomly administered to 36 infants 1-6 months old and 36 infants 7-15 months old 30-90 minutes before induction of anesthesia. The onset of action of atropine was approximately 25 minutes after administration as determined by a 15% increase in heart rate (HR) above baseline levels. Heart rate, systolic blood pressure (SBP), and mean arterial blood pressure (MAP) were then measured at 1-minute intervals starting just before induction of anesthesia and continuing until onset of surgical stimulation during anesthesia with halothane (up to 3%), nitrous oxide (60%), and oxygen (40%). In infants 1-6 months old, either dosage of oral atropine preserved HR and SBP as compared with placebo. In infants 7-15 months old, either dosage preserved HR but not SBP. The severity of hypotension was greatest in infants 1-6 months of age given placebos. No significant differences existed between oral atropine 0.04 mg/kg or 0.02 mg/kg in either age range. It is concluded that premedication with oral atropine 0.02 mg/kg is effective in attenuating the cardiovascular depression associated with halothane anesthesia in infants.
authors.affiliation: Department of Anesthesiology, Children's Hospital, Denver, Colorado.
authors.forename: B R
authors.initials: BR
authors.lastname: Miller
authors.forename: R H
authors.initials: RH
authors.lastname: Friesen
mesh_terms: D000284:Administration, Oral; D000704:Analysis of Variance; D001285:Atropine / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D001794:Blood Pressure / Q000187:drug effects*; D002986:Clinical Trials as Topic; D004311:Double-Blind Method; D006221:Halothane / Q000009:adverse effects / Q000037:antagonists & inhibitors*; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D007223:Infant; D011292:Premedication; D011446:Prospective Studies; D011897:Random Allocation; D013599:Systole / Q000187:drug effects; D013997:Time Factors
chemical_list: D001285:Atropine; D006221:Halothane