Atracurium in infants and children.

For atracurium, as for other neuromuscular blocking agents, the determination of potency in children has been assessed using the evoked response of the adductor muscle of the thumb. This response has been evaluated either by an electromyogram (EMG) or by a recording of the force of contraction through a force displacement transducer. The method of stimulation was either the train-of-four (2 Hz, 2 s) or the single twitch at a frequency of 0.1 Hz. The method of drug administration has varied with different clinical studies. Some have used the incremental dose technique in which repeated doses are given to the same patient (Goudsouzian etal., 1983; Goudsouzian, Liu et al., 1985); others have used the bolus method in which each group of patients received a different dose (Brandom, Rudd and Cook, 1983; Brandom et al., 1985). With long-acting blocking agents, both methods yield nearly identical data (Donlon et al., 1980), but with shortto intermediate-acting agents the incremental technique (Goudsouzian et al., 1983; et al., 1982) because the effect of the first dose partially dissipates before administration of the subsequent dose.