Reversal agents for nondepolarizing neuromuscular blockade: Reasons for and development of a new concept

Abstract

T HE INTRODUCTION of muscle relaxants into clinical anesthesia had an enormous impact on the possibilities of the surgical treatment of patients. The development of cleaner and shorteracting nondepolarizers with a benzylisoquinoline or a steroidal chemical structure further improved clinical anesthesia. However, their introduction coincided with a relatively high morbidity and mortality rate compared with anesthetic techniques when relaxants are not administered. 1 This is mainly caused by the occurrence of postoperative residual curarization, resulting in hypoxemia and airway obstruction. 2'3 Although the incidence of residual curarization with the newer intermediately short-acting and short-acting relaxants is lower than with the older long-acting relaxants, it still poses a problem. 4 The nondepolarizing relaxants still do not have a fast onset of action combined with a short duration of action. When a rapid onset is needed, a high dose is needed, causing a prolonged neuromuscular blockade, frequently outlasting the duration of surgery. Besides, a long duration of action may also cause a problem in the rare situation of intubate, cannot ventilate, which requires immediate restoration of spontaneous ventilation. In the clinical situation, an unexpected long duration of action of nondepolarizing relaxants may occur caused by an interaction with other drugs or by concurrent diseases present in the patient. With the current muscle relaxants, the possibility to reverse neuromuscular blockade thus remains important. For legal reasons, many anesthetists do routinely reverse neuromuscular blockade. 5 However, with the current reversal agents, this only provides an unjustified