Pipecuronium revisited: dose-response and maintenance requirement in infants, children, and adults.

STUDY OBJECTIVE: To compare dose-response relationship and maintenance requirement of pipecuronium in anesthetized infants, children, and adults. DESIGN: Prospective, consecutive sample trial. SETTING: Operating room at a university hospital. PATIENTS: 15 infants (1-11 months), 15 children (3-10 years), and 15 adults (35-50 years) of ASA physical status I and II. INTERVENTIONS: Anesthesia was induced and maintained with N2O:O2 2:1 and 1 minimum alveolar concentration end-tidal halothane. The neuromuscular function was recorded by adductor pollicis electromyogram evoked by a train-of-four ulnar nerve stimulation at 20 second intervals. An individual cumulative log-probit dose-response curve was established and maintenance requirement of pipecuronium determined. Between-group comparisons were made by analysis of variance and Scheffe F-test. MEASUREMENTS AND MAIN RESULTS: Dose-response curves were parallel with a dose-requirement of pipecuronium similar in infants and adults (ED95 of 40-42 micrograms/kg) and greater in children (ED95 of 52 micrograms/kg). After 30 minutes of surgical neuromuscular block, pipecuronium was required in each age group at a rate of 0.6 to 0.7 individual ED95 doses per hour to maintain an 85% to 95% neuromuscular block. CONCLUSIONS: Bolus dose requirement of pipecuronium is greatest in children. Maintenance requirement is related to potency in each age group studied.