THE ROLE OF HISTAMINE IN THE CARDIOVASCULAR EFFECTS OF ATRACURIUM

We have investigated the effect of a bolus injection of atracurium0.6mg kg^–1 on the cardiovascular system in 16 patientsundergoing aortocoronary bypass surgery. H₁- and H₂-receptorantagonists were administered to eight patients before the neuromuscularblocker. A standard anaesthetic was used comprising fentanyl,flunitrazepam, etomidate and enflurane. After administrationof atracurium, haemodynamic changes and plasma histamine concentrationswere measured at frequent intervals. In the first group, whoreceived only atracurium, a brief but marked decrease in SVRand MAP occurred, accompanied by an increase in Cl, togetherwith a marked increase in plasma concentration of histamine.In the second group, who received H₁ and H₂-receptor block,there was no decrease in MAP and only a small increase in plasmahistamine concentration. However, there were significant changesin SVR and Cl similar to those in the atracurium group.