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