MODERN MUSCLE-RELAXANTS AND THEIR USE IN CLINICAL-PRACTICE

Various new muscle relaxants are available: atracurium, rocuronium and vecuronium all have an intermediate duration of action, whereas doxac urium and pipecuronium are long-acting and mivacurium is a short-actin g nondepolarizing muscle relaxant. The duration of action of atracuriu m and mivacurium is determined by their degradation, which makes them unique among the nondepolarizing muscle relaxants in this respect. The time of onset is shortest with rocuronium, while vecuronium is probab ly the muscle relaxant with the fewest undesirable side-effects. Tn cl inical practice, muscle relaxants of short and intermediate duration o f action should be preferred, since such agents carry the least risk o f residual neuromuscular block postoperatively. Because recovery from them is slow, long-acting agents should preferentially be used only wh en postoperative mechanical ventilation is intended. The use of a peri pheral nerve stimulator is the only reliable guide to appropriate admi nistration of muscle relaxants.