Electromyographic monitoring of neuromuscular block.

Neuromuscular blocking agents are widely used in anaesthesia, and a simple quantitative method of monitoring their effects is desirable. This paper describes a new instrument which has been developed for electromyographic monitoring of neuromuscular block by a non-invasive technique which is both reliable and easy to use. The median nerve is stimulated at the wrist and the electromyogram (e.m.g.) from a thenar muscle is detected, rectified and integrated electronically to produce a meter display of the assessment of block. The method is recommended for routine use.