Clinical use of peripheral nerve stimulators in anaesthesia.

The use of the peripheral nerve stimulator is essential for adequate assessment of the degree of neuromuscular block. To ensure that the data derived are accurate one must understand the effects of stimulus frequency, electrode type, position and polarity, stimulus intensity, duration, waveform and the various ways used to observe the data, electromechanical, EMG, tactile or visual. Once these features are understood, a better interpretation of the various tests is possible. While a lot of information regarding the proper use of the PNS is derived from meticulous scientific experimentation, it is possible to apply this information for clinical use. Most information is available based on ulnar nerve stimulation. Information on stimulation of other nerves (e.g., current to achieve SMS on the peroneal nerve) is lacking. With this in mind, the authors present in Table III the minimum requirements for a PNS and an algorithm to illustrate use of the PNS, in Figure 6.