Effects of clonidine and superficial cervical plexus block on hemodynamic stability after carotid endarterectomy.

Objectives: To evaluate the effects of 2 interventions (intravenous clonidine and superficial cervical block) on hemodynamic stability after carotid endarterectomy and to identify variables associated with hemodynamic instability.

Design: Prospective, observational study, sequential enrollment.

Setting: University hospital.