The aim of this study is comparing the effect on cerebral oxygenation by sevoflurane-remifentanil or propofol-remifentanil anesthesia in patient undergoing carotid endarterectomy. Cerebral oxygenation is measured by near-infrared spectroscopy. Sevoflurane and propofol reduce the cerebral metabolic rate for oxygen in similar degree. Propofol decrease the cerebral blood flow by dose-dependent manner, however, sevoflurane increase the cerebral blood flow in the concentration of avobe 1 MAC. Both drugs are widely used in general anesthesia for neurosurgical procedure, and their effect on cerebral oxygenation are acceptable. There is little data about the effect of general anethetics on cerebral oxygenation in patients undergoing carotid endarterectomy, who have imparied cerebral circulation. Our hypothesis is sevoflurane will show better cerebral oxygenation than propofol in patient have impaired cerebral circulation.

This study is performed by monitoring the cerebral oxygenation using near-infrared spectroscopy from general anesthesia induction to 10 min after releasing the carotid artery clipping.

Study group: Sevoflurane - remifentanil anesthesia group (S) Propofol - remifentanil anesthesia group (R)

Monitoring: near-infrared spectroscopy (SOMA sensor) BIS, HR, arterial blood pressure, SpO2, body temperature

Patient seletion

• inclusion criteria

  • American Society of Anesthesiologist (ASA) physical status 1-3
  • 18 ~ 70 years
  • patient who agree with informed concent

• exclusion criteria

  • ASA physical status > 4
  • preoperative SpO2 < 97%
  • patient who has other neurologic disease not related to carotid endarterectomy

Inclusion Criteria:

• American Society of Anesthesiologist (ASA) physical status 1-3
• 18 ~ 70 years
• patient who agree with informed consent

Exclusion Criteria:

• ASA physical status > 4
• preoperative SpO2 < 97%
• patient who has other neurologic disease not related to carotid endarterectomy