On-line control of atracurium induced muscle relaxation.

We described recently a microcomputer system capable of controlling muscle relaxation during surgical procedures; the system was tested and evaluated in 42 clinical trials involving the use of the muscle relaxant, d-tubocurarine. The advent of new non-depolarizing neuromuscular blocking drugs with significant clinical advantages makes it essential that any automatic control system for muscle relaxation can also be used with such drugs, and benefit from their improved properties. This paper describes a series of 22 clinical trials in which our controller was used successfully to control muscle relaxation using atracurium. We also investigated an alternative control strategy, taking advantage of the rapid elimination of atracurium from the body.