SummaryBackground and aimWe investigated the haemodynamic stability and emergence characteristics of isoflurane/nitrous oxide anaesthesia supplemented with remifentanil or fentanyl in patients undergoing carotid endarterectomy.MethodsAnaesthesia was induced with propofol (1–2 mg kg−1) and either remifentanil (0.5 µg kg−1) or fentanyl (1 µg kg−1), followed by an infusion of remifentanil (0.2 µg kg−1min−1) or fentanyl (2 µg kg−1h−1).ResultsThere were no significant differences between the groups in haemodynamic variables, postoperative pain, nausea or vomiting. After induction there was a significant decrease in mean arterial pressure for both groups (P< 0.001) and a decrease in heart rate (P= 0.001) in the remifentanil group. In both groups these haemodynamic changes continued during maintenance of anaesthesia (P< 0.05). The time to eye opening after surgery was significantly shorter with remifentanil compared with fentanyl (6.62 ± 3.89 vs. 18.0 ± 15.18 min,P= 0.015).ConclusionRemifentanil appears to be a comparable opioid to fentanyl when supplementing isoflurane/nitrous oxide anaesthesia for carotid endarterectomy.