Jugular venous neurone specific enolase (NSE) increases following carotid endarterectomy under general, but not local, anaesthesia.

Abstract

Previous studies indicate that local (LA) rather than general anaesthesia (GA) for carotid endarterectomy (CEA) is associated with reflex hypertension and preservation of cerebral cytochrome oxidase after carotid clamping. The hypothesis that LA offers protection against ischaemic cerebral injury has been investigated by measuring ipsilateral jugular venous neurone specific enolase (NSE: neuronal glycolytic enzyme) and S-100B (glial cell protein) during and after CEA. 27 patients with symptomatic carotid artery disease (70-99% stenosis) underwent CEA, 14 under LA and 13 under GA. Jugular venous blood samples were assayed for NSE and S-100B before carotid clamping and at 5min before and 5min, 2, 4, 6, 8, 12 and 24h after clamp release. No neurological complications occurred. S-100B levels were low and did not increase from baseline in either group. Pre-clamp NSE levels were similar in both groups (LA: 17.6 (15.2-20.7)microg/l, GA: 21.5 (11.3-26.2)microg/l; p=0.37) but increased significantly 2h after clamp release in GA patients (LA: 25.5 (16.6-27.8)microg/l, GA: 48.2 (31.4-61.3)microg/l, p=0.05) with a significant rise from baseline in GA patients (p=0.04). CEA performed under GA is associated with greater rises in jugular venous NSE, and hence cerebral injury, than CEA performed under LA.