Comparison of Cumulative and Single Bolus Dose Techniques for Determining the Potency of Vecuronium

Abstract

The potency of vecuronium was determined using single bolus dose administrations of 10-50 micrograms kg-1 in 28 patients anaesthetized with thiopentone, nitrous oxide, oxygen and fentanyl. The results were compared with those previously obtained using a cumulative dose technique in a comparable group of 10 patients. The 50% and 95% blocking doses (ED50 and ED95) of vecuronium were found to be 23.1 and 39.6 micrograms kg-1, respectively. These were significantly lower than the 30.5 and 56.7 micrograms kg-1 obtained previously using the cumulative dose technique. We recommend the use of single bolus dose method of determining potency for relatively shorter-acting drugs like vecuronium.

L’anesthésie intraveineuse totale avec le propofol augmente la puissance du mivacurium

“…2 The potency for mivacurium was determined using the incremental dose method. 9 Although it has been postulated by some authors that, in comparison to the single-dose method, the determination of the potency of shorter-acting neuromuscular blocking drugs produces lower values, when the incremental dose method is used, 14,15 no previous study compared both methods for mivacurium. For the purpose of this study, comparing NMBA drug potency during two different durations of TiVA propofol, the use of the incremental dose method was deemed to be sufficiently accurate, since it was the difference, rather than the absolute value, of drug potency which was the focus of the investigation.…”

Dose-response and time-course of the effect of rocuronium bromide during sevoflurane anaesthesia

“…The incremental cumulative dose technique was used to evaluate the dose-response relationship of rocuronium in the current study. Some investigators have found that the cumulative dose technique may underestimate the potency of neuromuscular blocking agents with rapid distribution and elimination [19][20][21][22]. However, administration of rocuronium was consistent throughout the study and the patients were chosen randomly, thus the degree of redistribution would have been similar in the two groups of patients.…”

Comparative Potency of Pipecuronium Bromide and Pancuronium Bromide

“…The method of estimating potency has been shown to be important [3,4]. Although these studies have shown that a single dose method of estimating potency is more accurate for relatively shorter acting neuromuscular blocking drugs, these have shown no significant difference in the case of agents with a relatively long duration of action.…”