title: Intramuscular rapacuronium in infants and children: a comparative multicenter study to confirm the efficacy and safety of the age-related tracheal intubating doses of intramuscular rapacuronium (ORG 9487) in two groups of pediatric subjects.
abstract: BACKGROUND
  This multicenter, assessor, blinded, randomized study was conducted to confirm and extend a pilot study in which intramuscular rapacuronium was given to infants and children to confirm efficacy and to evaluate tracheal intubating conditions.
  
  
  METHODS
  Ninety-six pediatric patients were studied in two groups: infants aged 1 to 12 months (n = 46) and children aged 1 to 3 yr (n = 50). Infants received 2.8 mg/kg and children 4.8 mg/kg of intramuscular rapacuronium during 1 minimum alveolar concentration halothane anesthesia. These two groups were studied in three subgroups, depending on the time (1.5, 3, or 4 min) at which tracheal intubation was attempted after the administration of intramuscular rapacuronium into the deltoid muscle. Neuromuscular data collected included onset time, duration of action, and recovery data during train-of-four stimulation at 0.1 Hz. Data were analyzed by the Cochran-Mantel-Haenszel procedure.
  
  
  RESULTS
  The tracheal intubating conditions were deemed acceptable in 17, 36, and 64% of infants and 20, 47, and 71% of children at 1.5, 3, or 4 min, respectively. The mean values for % of control twitch height (T1) 2 min after rapacuronium in both groups were similar. The mean (SD) time required to achieve more than or equal to 95% twitch depression in infants was 6.0 (3.7) versus 5.5 (3.8) min in children.
  
  
  CONCLUSIONS
  Only 27% of patients achieved clinically acceptable tracheal intubating conditions at 1.5 or 3 min after administration of 2.8 mg/kg and 4.8 mg/kg rapacuronium during 1 minimum alveolar concentration halothane anesthesia. Tracheal intubation conditions at 4 min were acceptable in 69% of subjects. The duration of action of 4.8 mg/kg of rapacuronium in children was longer than 2.8 mg/kg of rapacuronium in infants.
authors.affiliation: Department of Anesthesia, Massachusetts General Hospital, Boston, Massachusetts, USA. WDenman@lifespan.org
authors.forename: W T
authors.initials: WT
authors.lastname: Denman
authors.forename: R F
authors.initials: RF
authors.lastname: Kaplan
authors.forename: N G
authors.initials: NG
authors.lastname: Goudsouzian
authors.forename: T
authors.initials: T
authors.lastname: Uejima
authors.forename: S L
authors.initials: SL
authors.lastname: Barcelona
authors.forename: C J
authors.initials: CJ
authors.lastname: Cote
authors.forename: B
authors.initials: B
authors.lastname: Ginsberg
authors.forename: R S
authors.initials: RS
authors.lastname: Hannallah
mesh_terms: D000769:Anesthesia, Inhalation; D002675:Child, Preschool; D005260:Female; D006221:Halothane; D006801:Humans; D007223:Infant; D007273:Injections, Intramuscular; D007442:Intubation, Intratracheal; D008297:Male; D003473:Neuromuscular Nondepolarizing Agents / Q000008:administration & dosage* / Q000009:adverse effects; D014673:Vecuronium Bromide / Q000008:administration & dosage* / Q000009:adverse effects / Q000031:analogs & derivatives*
chemical_list: D003473:Neuromuscular Nondepolarizing Agents; D014673:Vecuronium Bromide; C082938:rapacuronium; D006221:Halothane