Management of muscle relaxation during target-controlled anaesthesia

Muscle relaxation is an essential component of adequate anaesthesia. Because of inter-individual variations in the response to neuromuscular blocking agents, monitoring should be used. The limitations of current monitoring modalities should be understood, and this applies chiefly to the assessment of recovery. Many methods (double burst stimulation, submaximal stimulation, 100-Hz tetanus, assessing the movement of the index finger) have been proposed for improving the detection of fade. A large bolus dose is usually required for tracheal intubation, because the muscles that must be relaxed for this purpose are resistant to the effect of non-depolarizing drugs. Maintenance of relaxation may be achieved by bolus or infusions. Closed-loop systems have been designed for this purpose. Adequate assessment of recovery should be made to avoid residual paralysis and, under most circumstances, reversal should be used.