title: Effect of intraoperative analgesic therapy on end-expired concentrations of halothane associated with spontaneous eye opening in children.
abstract: We studied 94 healthy ASA physical status I or II children to determine the end-expired concentration of halothane associated with eye opening on emergence from anesthesia, and to determine if parenteral opioid therapy or regional analgesia significantly altered this concentration. In our study, anesthesia was maintained with halothane in an air-oxygen mixture. After the surgical procedure was completed, the inspired concentration of halothane was adjusted to zero and the end-expired concentrations were permitted to decrease spontaneously. The end-expired concentration at which the child spontaneously opened his or her eyes was recorded. There were no statistically significant differences in the values of the end-expired halothane concentration at eye opening between patients in the control group, who did not receive any supplementation of halothane anesthesia, and patients in the groups that received either morphine supplementation or regional analgesia. These data suggest that analgesia and hypnosis (or loss of consciousness) occur by different mechanisms during halothane anesthesia in children.
authors.affiliation: Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: M F
authors.initials: MF
authors.lastname: Watcha
authors.forename: R G
authors.initials: RG
authors.lastname: Lagueruela
authors.forename: P F
authors.initials: PF
authors.lastname: White
mesh_terms: D000293:Adolescent; D000698:Analgesia / Q000379:methods; D000762:Anesthesia Recovery Period; D000769:Anesthesia, Inhalation; D002648:Child; D002675:Child, Preschool; D005260:Female; D006221:Halothane / Q000008:administration & dosage / Q000032:analysis*; D006801:Humans; D007223:Infant; D007432:Intraoperative Period; D008297:Male; D009020:Morphine; D009407:Nerve Block; D009609:Nitrous Oxide; D009799:Ocular Physiological Phenomena; D012119:Respiration
chemical_list: D009020:Morphine; D009609:Nitrous Oxide; D006221:Halothane