The provision of neuromuscular block is a fundamental part of balanced anaesthesia. It is important that the degree of neuromuscular block is sufficient to provide adequate surgical conditions, while not so excessive as to make it difficult to antagonize at the end of surgery. Developed system for automatic delivery of neuromuscular blockers (RelaxA) comprised a general purpose IBM-compatible computer (PC) interfaced to a Datex AS/3™ NMT (neuromuscular transmission) monitor and Graseby Medical 3400 infusion pump. Datex AS/3™ was used to measure NMT every 20 sec while the PC was programmed to instruct the infusion pump to administer an atracurium infusion to maintain stable neuromuscular block (target level – 10 % of baseline). The system achieved stable control of neuromuscular block in 80 patients with a mean T1 error of –0.43 % (SD 0.36 %) accommodating a range in mean atracurium infusion rate of 0.11–0.46 mg . kg -1 . hr -1 . Precision of the regulation was far beyond that which was clinically required.

        Key words: neuromuscular block – automatic control – monitoring – neuromuscular blocking agent