The onset of pipecuronium following application of the priming principle

Pipecuronium bromide, a long acting non-depolarizing neuromuscular blocking agent was administered to four groups of 10 patients using the priming technique.The effects of the combination of two different priming doses (0.01 or 0.015 mg kg−1) given at two different time intervals (3 or 4 min) before the ‘main’ intubating dose (0.07 or 0.065 mg kg−1) were investigated. Onset times were recorded and the intubation conditions were scored and compared with a group of patients receiving the same total amount of pipecuronium(0.08 mg kg−1) in a single bolus injection. Intubating conditions at 90 s after administration of the intubating dose were found to be significantly improved in all primed groups but the onset times, evaluated using the response of the adductor pollicis muscle to a single twitch stimulation, were similar to that observed after the single bolus injection. The optimal priming combination is considered to be 0.01 mg kg−1 of pipecuronium followed 3 to 4 min later by 0.07 mg kg−1.