Isoflurane: effect on the encephalogram during carotid endarterectomy

Area of Science:

• Anesthesiology
• Neuroscience
• Cardiovascular Science

Background:

• Carotid endarterectomy requires careful anesthetic management to monitor cerebral blood flow.
• Isoflurane is a common inhalation anesthetic used in surgical procedures.

Purpose of the Study:

• To evaluate the impact of isoflurane on electroencephalogram (EEG) monitoring during carotid endarterectomy.
• To assess if isoflurane affects the detection of cerebral ischemia during carotid artery occlusion.
• To determine the effects of isoflurane on hemodynamic parameters, specifically mean arterial pressure (MAP).

Main Methods:

• Patients undergoing carotid endarterectomy were monitored using electroencephalography.
• Isoflurane was administered at increasing concentrations.
• Cerebral ischemia was induced by temporary occlusion of the internal carotid artery.
• Mean arterial pressure was recorded throughout the procedure.

Main Results:

• Isoflurane caused dose-dependent changes in the electroencephalogram.
• The anesthetic did not impair the ability to detect cerebral ischemia during carotid artery occlusion.
• Isoflurane concentrations of 1.0% and 1.5% led to significant reductions in mean arterial pressure.

Conclusions:

• Isoflurane can be used during carotid endarterectomy without compromising the EEG-based detection of cerebral ischemia.
• The significant decrease in mean arterial pressure associated with isoflurane use is a concern for patients undergoing vascular surgery, necessitating careful hemodynamic management.