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

Abstract

We have measured the haemodynamic effects of mivacurium 0.15 and 0.2 mg kg-1, and atracurium 0.5 mg kg-1 administered over 10-15 s in patients undergoing coronary artery bypass surgery under fentanyl anaesthesia. There were no significant haemodynamic changes in the atracurium group, other than a transient decrease in pulmonary arterial wedge pressure. Changes in heart rate were small in all three groups. Mivacurium 0.15 mg kg-1 produced changes of only small magnitude (12% decrease in mean arterial pressure and 16% decrease in systemic vascular resistance index) however, mivacurium 0.2 mg kg-1 produced a 25% reduction in mean arterial pressure, a 14% increase in cardiac index and a 35% decrease in systemic vascular resistance index. Erythema developed in two, three and seven patients after atracurium, mivacurium 0.15 mg kg-1 and mivacurium 0.2 mg kg-1, respectively. One patient exhibited a 54% decrease in mean arterial pressure, generalized erythema and bronchospasm after mivacurium 0.2 mg kg-1. The haemodynamic changes with mivacurium suggested histamine release.