Comparaison des profils tensionnels sous flunitrazépam/fentanyl/N 2O vs anesthésie péridurale cervicale pour chirurgie carotidienne

Abstract

A study was carried out to compare the evolution of arterial blood pressure during carotid endarterectomy performed under either general anaesthesia (GA) or cervical epidural anaesthesia (CEA). 20 patients were randomly assigned to two equal groups. In the CEA group, 15 ml of 0.375 % bupivacaine and 150 μg fentanyl were injected into the epidural space at C7-D1 level. In the GA group, patients were anaesthetized with 0.2 mg · kg −1 flunitrazepam and 5 μg · kg −1 fentanyl ; intubation was carried out using 0.08 mg · kg −1 vecuronium, and the patients were ventilated with a mixture of nitrous oxide and oxygen (50 % of each). Further injections, every 30 min, of 2 μg · kg −1 fentanyl were given to the patients in group GA. Blood pressure was monitored continuously, up to 4 h postoperatively, with a radial arterial catheter. Per- or postoperative hypertension was defined as a rise in systolic arterial blood pressure (Pa sys) over 180 mmHg for > 3 min ; this was treated with 20 mg nifedipine intranasally (group CEA) or 100 μg fentanyl with 0.5 mg flunitrazepam with or without nifedipine (group GA). Per- or postoperative hypotension was defined as a fall in Pa sys below 100 mmHg and or a 30 % fall in mean arterial blood pressure for > 3 min ; this was treated, in both groups, with an intravenous bolus of 3 mg ephedrine. Patients in group CEA experienced more frequent episodes of peroperative hypertension (8/2 ; p < 0.02) and postoperative hypotension (5/1) than group GA. Although CEA was expected to induce a sympathetic block which could have reduced haemodynamic disturbance during and after surgery, there was no greater haemodynamic stability in group CEA. Both an accurate monitoring and blood pressure control remain the main problems of carotid endarterectomy whatever the anaesthetic technique used.