Onset of vecuronium-induced neuromuscular block after a long priming interval
Lung function and clinical evidence of muscle weakness were assessed in 12 ASA I patients who received vecuronium 0.01 mg kg-1 pretreatment as a part of their anaesthetic management, before and 3 min after pretreatment. Most patients demonstrated ptosis and diplopia, while five of the 12 were unable to raise the head for > 4 s and had difficulty in swallowing. Significant reductions occurred in forced vital capacity, forced expiratory volume in 1 s, and maximum mid-expiratory flow rate. Among static lung volumes, functional residual capacity and expiratory reserve volume decreased significantly. However, these changes were not serious enough to cause clinically significant impairment of coughing or a decrease in oxygen saturation in any patient.