The clinical experiment to develop the brain protection protocol in cerebral ischemia using compressed spectral array

Abstract

Objective：The clinical experiment to establish the cerebral protection protocol for hemodynamically vulnerable patients from ischemic insult during surgery is presented.

Methods：The experiment divided in two parts, one is to analyze the effect of intravenous anesthetics and inhalation anesthetics on EEG activity in neurologically intact 81 patients. The others is to develop the stepwise cerebral protection protocol during aneurysm surgery which required temporary clipping, carotid endarterectomy and extracranial intracranial arterial bypass surgery in 61 patients. The cerebral protection protocol included the use of intraoperative compressed spectral array(CSA) monitoring, induced hypertension, thiopental induced burst suppression and moderate hypothermia.

Results：With the efforts of brain protection protocol, 59 of the 61 patients recovered without any newly developed neurological deficit from the surgery. One patient had carotid stenosis with multiple untreated aneurysms, and therefore, induced hypertension was not applied. This patient developed significant postoperative neurological deficits correlated well with the CSA changes. In one patient who has cerebral aneurysm, thiopental bolus injection was used. This patient has reduction of EEG activity during temporary clipping and developed the relatively well correlated neurologic deficit postoperatively. Among 28 carotid endarterectomy cases, three patients has definite reduction of EEG activities within 7 to 15 seconds of interval carotid artery(ICA) test clamping before endarterectomy. But, these patients recovered from surgery without any neurological deficit inspite of 28 to 35 minutes ICA clamping with the effort of thiopental induced burst suppression, induced hypertension and moderate hypothermia.

Conclusion：Cerebral protection protocol under CSA monitoring could prevent ischemic insults from circulatory disruption on vulnerable ischemic hemisphere.