Dose‐response Curves for Vecuronium during Halothane and Neurolept Anaesthesia: Single Bolus versus Cumulative Method

Abstract

The incremental, cumulative dose method and the single bolus injection technique for construction of dose-response curves for vecuronium were compared. Dose-response curves were determined in 77 patients divided into 4 groups according to the anesthetic given and the method used for construction of dose-response curves. The regression lines corresponding to the 4 dose-response curves were found to be parallel. For vecuronium ED50 [effective dosage] during neurolept anesthesia was 28 .mu.g kg-1 with the single bolus injection technique and 35.2 .mu.g kg-1 with the incremental, cumulative dose method (P < 0.05). During halothane anesthesia, ED50 was 25.7 .mu.g kg-1 and 26.2 .mu.g kg-1, respectively, (P > 0.05). Potentiation of vecuronium by halothane was found with the cumulative method only. The incremental, cumulative dose method is not suitable for potency determinations of vecuronium.