Priming with nondepolarizing relaxants for rapid tracheal intubation: a doubleblind evaluation

Abstract

Succinylcholine has long been the standard muscle relaxant for facilitation of rapid tracheal intubation. In the patient at high risk for aspiration a rapid-sequence induction with suceinylcholine is often utilized. Due to its rapid onset succinyleboline has also retained its position in elective anaesthetic induction, However, succinylcholine has a number of undesirable side-effects, detracting from its use in many clinical settings. Therefore, an alternative relaxant fascilitating intubation as rapidly as succinylcholine would be desirable. It has been suggested that utilizing a divided-dosage regimen, the priming principle, excellent intubating conditions can be rapidly produced with nondepolarizing relaxants alone, thus eliminating the need for suocinyleholine. 1,2 This paper reports the results of a series of randomized, double-blind trials investigating this hypothesis. MethodsThis study was conducted in three phases. The first two phases were conducted at Brooke Army Medical Center (BAMC) and the third phase at Landstuhl Army Regional Medical Center (LARMC). The study was approved by the Institutional Review Board at BAMC and by the Hospital Ethics Committee at LARMC. All patients gave written informed consent. Adult ASA physical status 1 and 1I patients weighing more than 45 kg and scheduled for elective surgery were eligible for the study. The following patients were excluded; those with asthma, those at high risk for aspiration (e.g., hiatus hernia, pregnancy, morbid obesity), and those in whom a difficult intubation was anticipated. Additionally, any patient with a history of sensitivity to any of the medications specified by the protocol or in whom any of the medications were contraindicated was excluded.The protocols and dosages are summarized in

Dose preparatória versus injeção única: estudo comparativo entre diferentes doses de cisatracúrio

“…Esta técnica, por encurtar o tempo de latência de bloqueadores neuromusculares de duração de ação intermediária e de longa duração, constitui alternativa às altas doses para intubação traqueal. Além disso, o emprego de uma menor dose total (dose preparatória mais dose de intubação traqueal) pode levar à menor duração clínica e à rápida recuperação 2,4-6, [11][12][13][14][15] . Adose subparalizante embora insuficiente para produzir bloqueio neuromuscular, ocuparia um considerável número de receptores pós-sinápticos, diminuindo a margem de segurança da transmissão neuromuscular e permitindo o aparecimento mais rápido do efeito da segunda dose 16,17 .…”

“…This technique, for shortening intermediate and long duration neuromuscular blockers onset time, is an alternative for high tracheal intubation doses. In addition, a lower total dose (priming plus tracheal intubation dose) may lead to shorter duration and faster recovery 2,4-6, [11][12][13][14][15] .…”

Optimum priming dose of vecuronium for tracheal intubation

“…Therefore, the priming technique has been practiced to reduce onset time. A priming dose of vecuronium of approximately 10~tg.kg -~ is recommended [3][4][5]. Mahajan and D'Honneur et al recently reported, however, that 10 gg.kg-~ of vecuronium has caused impairment of pulmonary function [6], lowered glossal muscle activity on electromyography (EMG) [7], and resulted in swallowing difficulty in some cases [6].…”

“…For quick and smooth tracheal intubation with vecuronium, many anesthesiologists have used large doses of vecuronium [1][2] or the so-called priming technique [3][4][5]. Although the former is simple and effective, it is not suitable for brief operations.…”

The priming saga: where do we stand now?

“…Using vecuronium, Baumgarten et al 7 report an improvement in intubating conditions with 0.01 mg.kg-' followed by 0.09 rag. kg-i when compared with 0.1 mg-kg-i but two studies have failed to confirm this benefit for comparable doses of atraeurium.…”