MIVACURIUM AFTER ATRACURIUM IN CHILDREN

The effect of mivacurium after atracurium was evaluated in 36 children anesthetized with halothane-nitrous oxide-oxygen by measuring the for ce of contraction of the adductor pollicis during train-of-four stimul ation at 0.1 Hz. The children were evaluated in two main groups. In Gr oup 1 the effect of bolus doses of mivacurium after equipotent repeat doses of atracurium were evaluated. When the first twitch of the train -of-four response (T1) had recovered to 25% of control after a trachea lly intubating dose of atracurium, a repeat dose of atracurium was giv en, on subsequent recovery to 25%, an equipotent dose of mivacurium wa s administered. In Group 2 when T1 had recovered to >10% from 0.5 mg/k g atracurium, a mivacurium infusion was started; the initial infusion rate was 4 mu g.kg(-1).min(-1) with adjustments made to maintain 90%-9 9% depression of T1. Patients were allowed to recover spontaneously fr om the effect of the relaxants.