Asleep-awake-asleep technique during carotid endarterectomy: a case series

Objective: Carotid endarterectomy (CEA) has become one of the most common vascular procedures in the world. It can be performed both under general anesthesia (GA) and regional anesthesia (RA). The aim of this study was to present results of a technique for CEA in which the patients anesthetized with target-controlled infusions of propofol and remifentanil were awake during the endarterectomy phase. Neurologic function was evaluated as if under RA. Patient satisfaction and the incidence of major complications also were investigated.

Design: A prospective nonrandomized case series.

Setting: A single-institution, regional hospital.

Participants: One hundred eight patients with carotid artery stenosis undergoing CEA.

Interventions: Anesthesia was induced using TCI remifentanil at an initial effect-site concentration of 3 ng/mL and propofol TCI at an effect-site concentration of 2.5 to 3 microg/mL. Both drugs gradually were reduced shortly before the clamping phase until the patients were awake. The patients were asked to squeeze a child's toy placed in the contralateral hand from the side of the operation. If a deficiency of motor function occurred, the level of anesthesia was increased and a shunt was inserted. When the carotid artery was unclamped and there was no evidence that any other neurologic deficiency had occurred, both propofol and remifentanil infusions were increased until the patient fell asleep.

Measurements and results: Seventeen patients (15.7%) developed a neurologic deficiency within 13 minutes of the carotid artery clamping, which required a shunt. All patients were interviewed the next day; 2 patients (1.8%) felt a sense of anxiety when the technique was explained to them. No patients suffered from anxiety or agitation during the intraoperative awakening. One patient (0.9%) complained about discomfort because of the orotracheal tube, and 2 patients suffered from slight pain. One patient (0.9%) suffered from angina pectoris the following day, but no other major complication occurred. Six months later, a telephone interview was held with the patients included in the study; 5 had died and 2 had had a stroke within this period. All the interviewed patients judged this technique good, and they would recommend it to other patients.

Conclusions: Although this is a case series, the authors believe that this technique combines the advantages of RA (good evaluation of the patients' neurologic status) and GA (patients relaxed and comfortable). Moreover, the analysis of the results of the questionnaire suggests that the patients can tolerate the operation awake under propofol and remifentanil, and major complications also were low. It can be concluded that this technique appears to be safe and well accepted by patients and could be a good alternative in patients in whom RA cannot be performed.