Onsets of Train-of-Four Responses and Discomfort Associated with the Ulnar Nerve Stimuli at Varying Currents
An ulnar nerve stimulation at submaximal current is useful because it is less uncomfortable than at supramaximal stimulation. Further, some investigations also reported that train-of-four ratio(TOFR, T4/T1) remained consistent over a wide range of stimulating currents. To determine a recovery of neuromuscular transmission, nevertheless, not only TOFR but also the onsets of TOF responses, i. e., the first appearances of T1, T2, T3, and T4 are important. In this study the onsets of T1, T2, T3, and T4 responses were examined after administration of vecuronium during clinical anesthesia, and TOF stimulation-induced discomfort was evaluated at varying currents using visual analog scale(VAS) in awake volunteers.