Isoflurane does not increase the incidence of intraoperative myocardial ischaemia compared with halothane during vascular surgery.

Abstract

We have studied the incidence of new intraoperative myocardial ischaemia (IMI), myocardial infarction (MI) and cardiac death (CD) in 500 consecutive patients undergoing elective major non-cardiac vascular surgery. Patients were allocated randomly to receive either halothane (n = 226) or isoflurane (n = 274) as principal anaesthetic agent. Using real-time ST segment trend analysis (leads V5 and II) IMI (halothane 39%, isoflurane 38%), MI (halothane 1.3%, isoflurane 1.5%) and CD (halothane 0.4%, isoflurane 0.7%) did not differ significantly between the two groups. Twenty-three per cent of IMI episodes were related to haemodynamic disturbances, but unrelated to the type of surgery: 148 supra-aortic (IMI = 39%), 244 abdominal aortic (IMI = 41%) and 108 lower extremity revascularizations (IMI = 33%). We conclude that the choice of volatile anaesthetic agent does not influence cardiac morbidity or mortality in this type of patient.