Pretreatment with atracurium: the influence on neuromuscular transmission and pulmonary function

The influence of pretreatment with atracurium on neuromuscular transmission was evaluated in 60 healthy volunteers using train-of-four (TOF) nerve stimulation and measurement of respiratory rate (RR), vital capacity (VC), inspiratory force (IF), and peak expiratory flow (PEF). The subjects were randomly allocated to one of four groups: Group I received atracurium 0.02 mg/kg, Group II 0.03 mg/kg, Group III 0.04 mg/kg, and Group IV atracurium 0.05 mg/kg. TOF ratio decreased significantly in all four groups. There was, however, no difference between the groups after injection. PEF decreased significantly in all four groups, VC decreased in Groups I and IV, and RF increased significantly only in Group IV. Three subjects (5%) had shallow, frequent respiration; however, none needed respiratory support. The majority of the volunteers experienced blurring of vision and heavy eyelids: 82% and 67%, respectively. All subjects were able to sustain head lift for 10 s or more after atracurium. Careful observation of respiration is necessary, especially when using the higher doses of atracurium.