Remifentanil conscious sedation during regional anaesthesia for carotid endarterectomy: Rationale and safety

Objectives: to prospectively evaluate the safety and efficacy of remifentanil during regional anaesthesia for carotid endarterectomy. Methods: twenty-eight consecutive patients underwent carotid endarterectomy with combined superficial and deep cervical plexus block supplemented with continuous intravenous 0.04 μg·kg^-1·min^-1 remifentanil infusion. Depth of sedation was monitored using the Observer's Assessment of Alertness/Sedation Scale (OAA/S). The degree of pain, discomfort and anxiety was self-assessed by the patients using a horizontal visual analogue scale. Results: all patients experienced adequate comfort and analgesia. No local anaesthetic supplementation was necessary. No patient had a OAA/S score lower than 4 (with 5=awake/alert to 1=asleep). Respiratory depression did not occur. Selective shunting was required in four cases. No patient was converted to general anaesthesia. There were no permanent neurological deficits, cardiopulmonary complications or deaths. Conclusion: remifentanil as a supplement to regional aneasthesia for carotid endarterectomy, provides comfort and analgesia without hampering mental status evaluation.