Severe cardiovascular depression with remifentanil

We compared the hemodynamic effects of a bolus administration of 1 mu g/kg remifentanil for 1, 3, and 5 min (1, 0.33, and 0.2 mu g . kg(-1) . min(-1), respectively) in patients scheduled for coronary artery bypass grafting an esthetized with small-dose propofol. The study was terminated after only ei ght patients had been enrolled (three received remifentanil at a rate of 1. 0 mu g . kg(-1) . min(-1), two at 0.33 mu g . kg(-1) . min(-1), and three a t 0.2 mu g . kg(-1) . min(-1)) because of severe hemodynamic instability, w hich was particularly marked in four patients and consisted of severe brady cardia in one patient and severe hypotension with a reduction in systemic v ascular resistance in three others. One patient showed evidence of myocardi al ischemia. All patients responded to therapeutic interventions. The resul ts show that remifentanil should be given only by slow infusion to such pat ients.