An evaluation of eight peripheral nerve stimulators for monitoring neuromuscular blockade

The features of eight commercially available peripheral nerve stimulators were compared with those evolved as ideal for monitoring neuromuscular blockade. The pulse waveforms were satisfactory except for that delivered by the CIG series 80 nerve/muscle stimulator. The error in timing of the stimulation patterns was up to 60% in the Professional Instruments NS-2C compared with 8% or less in the other devices. All of the stimulators had maximum current outputs suitable for monitoring with surface stimulating electrodes. The current delivered by the CIG series 80 nerve/muscle stimulator and the Stimlocator SL1.4 sagged by 21% and 25% respectively during a tetanus. The Digistim III, Bard Biomedical 750 digital and the Professional Instruments NS-2C had accurate digital readouts of delivered current.