Clinical automatic control of neuromuscular blockade.

A simple feedback control technique has been used to automatically deliver pancuronium to anaesthetised surgical patients. The dosage rate is automatically adjusted at 10-second intervals, according to the measured evoked, rectified, integrated electromyogram. When set to demand 80 percent blockade, in 40 patients, the controller maintained blockade at a steady mean level of 72.9 percent (consuming pancuronium at a mean rate of 0.47 microgram/kg/minute). The main clinical practical problems involved protection against electrical noise and the need to spend time setting up the equipment.