The effect of different priming doses on the pharmacodynamics of cisatracurium

Objective: The aim of the study was to evaluate the effect of two different priming regimen on the onset time of 100 mu g/kg cisatracurium, when compa red to bolus administration. Methods: 51 patients were randomly assigned and received either a bolus of 100 mu g/kg cisatracurium, or a priming dose of 10 mu g/kg cisatracurium fo llowed after 4 min by 90 mu g/kg cisatracurium, ora priming dose of 15 mu g /kg cisatracurium followed after 4 min by 85 mu g/kg cisatracurium. The neu romuscular monitoring was performed using a mechanomyograph (Groningen II M onitor). Anaesthesia was induced with propofol and fentanyl and maintained by continuous infusion of propofol. Results: The priming combination of 15 mu g/kg cisatracurium followed after 4 min by 85 mu g/kg cisatracurium produced a statistically significant red uction in the onset time (95% block) (180+/-60 s) and time to complete bloc k (210+/-48 s), when compared to the bolus group (240+/-60 s and 288+/-66 s ) (p<0.05). Conclusion: Our data indicate that the "priming principle" is an appropriat e technique to shorten the onset time of cisatracurium. To achieve a maximu m effect the priming combination of 15 mu g/kg cisatracurium followed after 4 min by 85 mu g/kg cisatracurium is recommended.