Comparison of the haemodynamic effects of mivacurium and atracurium during fentanyl anaesthesia

We have measured the haemodynamic effects of mivacurium 0.15and 0.2 mg kg^–1, and atracurium 0.5 mg kg^–1 administeredover 10–15 s in patients undergoing coronary artery bypasssurgery under fentanyl anaesthesia. There were no significanthaemodynamic changes in the atracurium group, other than a transientdecrease in pulmonary arterial wedge pressure. Changes in heartrate were small in all three groups. Mivacurium 0.15 mg kg^–1produced changes of only small magnitude (12% decrease in meanarterial pressure and 16% decrease in systemic vascular resistanceindex) however, mivacurium 0.2 mg kg^–1 produced a 25%reduction in mean arterial pressure, a 14% increase in cardiacindex and a 35% decrease in systemic vascular resistance index.Erythema developed in two, three and seven patients after atracurium,mivacurium 0.15mgkg^–1 and mivacurium 0.2 mg kg^–1,respectively. One patient exhibited a 54% decrease in mean arterialpressure, generalized erythema and bronchospasm after mivacurium0.2mg kg^–1. The haemodynamic changes with mivacurium suggestedhistamine release. (Br. J. Anaesth. 1995; 74: 330–332)