Monitoring neuromuscular blockade and depth of anaesthesia

This article describes the main methods used to monitor the effects of muscle relaxants, and the ways in which they may be employed clinically to assess the effects of neuromuscular blockade and anticholinesterase drugs. It provides an overview of the main patterns of electrical stimulation used to assess residual muscle paralysis, including train-of-four and double burst stimulation. The article describes the techniques used to monitor depth of anaesthesia, and compares the advantages and disadvantages inherent in the methods currently in use. Methods based on processed electroencephalogram (EEG) signals are discussed, and include auditory evoked potentials (AEPs), bispectral index (BIS) and entropy.