The primary purpose of this study is to determine the dose requirements of rocuronium bromide when administered as a bolus dose (a single, large dose) for intubation (insertion of a tube through the nose or mouth into the trachea to provide artificial ventilation) and when administered by either continuous infusion or bolus doses for maintenance of muscle relaxation in term neonates (birth to <28 days old), infants (28 days to <=3 months) and toddlers (>3 months to <=2 years), children (2 years to less than or equal to 11 years of age), and adolescents (>11 years to less than or equal to 17 years of age).