Original Article Age and the neuromuscular blockading effects of cisatracurium

Purpose: To investigate the influence of age on the neuromuscular blocking effect of cisatracurium. Meth - ods: 90 patients with ASA I and II were assigned to the following groups according to their age: adults, children, and infants. Each group was subdivided into three subgroups according to the first dose of cisatracurium. Patients were administrated at a first dose of cisatracurium randomly, and their responses to train-of-four (TOF) stimulation were observed. When the same degree of the first response (T 1 ) continuously repeats three times, the percentage of T 1 inhibition was recorded, and the curve of dose-effect relationship and ED 95 were calculated. A second dose of cisa- tracurium was then administrated (total volume 100 μg/kg). The recovery phase in each patient was observed upon T 1 reaching the maximum blocking effect (100%). Results: Once the maximum blocking effect was reached, patients were intubated. There were 83 cases (92.2%) of patients with grade 1 and 7 (7.8%) patients with grade 2 intubating conditions. ED 95 was 59.29, 55.88 and 45.39 μg/kg in adults, children, and infants, respectively. ED 95 positively cor- related with age. The clinical duration of neuromuscular blockade, effective action duration of neuromuscular block- ade, and in vivo action duration of neuromuscular blockade in adults was longer than that in children (P 0.05). Conclusion: Age influences the neuromuscular blocking effects of cisatracurium to a certain extent.