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EEG bispectral index during carotid endarterectomy
1Dept. of Anesth. College of Medicine, King Saud Univ., Riyadh, 11461, P.O. Box: 2925, KSA. dawlatly@ksu.edu.sa
Insights
During carotid endarterectomy (CEA), the bispectral index (BIS) monitoring showed a significant decrease during internal carotid artery (ICA) clamping, indicating potential cerebral ischemia. Further research is needed to confirm BIS as a reliable indicator of cerebral perfusion during CEA.
Area of Science:
- Neurosurgery
- Anesthesiology
- Cerebrovascular Medicine
Background:
- Carotid endarterectomy (CEA) is a critical procedure for internal carotid artery (ICA) stenosis.
- Stroke is a primary risk during CEA, necessitating effective cerebral monitoring.
- The bispectral index (BIS) monitors anesthetic depth and has shown sensitivity to cerebral ischemia.
Purpose of the Study:
- To document changes in the bispectral index (BIS) during CEA under general anesthesia.
- To investigate the utility of BIS as a potential indicator of cerebral perfusion during CEA.
Main Methods:
- A study involving ten patients undergoing CEA under general anesthesia.
- Bispectral index (BIS) was measured across five perioperative phases: pre-anesthesia, pre-clamping, ICA clamping, post-declamping, and recovery.
- Statistical analysis compared BIS values across different phases.
Main Results:
- Mean BIS values varied significantly across phases, with notable decreases during ICA clamping (44.3 +/- 6.8) and post-declamping (54.7 +/- 8.3) compared to pre-anesthesia (91.4 +/- 5.6).
- Significant reductions in BIS were observed during phases B (pre-clamping), C (clamping), and D (post-declamping) relative to phase A (pre-induction).
Conclusions:
- A decreasing trend in the bispectral index (BIS) was observed during internal carotid artery (ICA) clamping in CEA.
- The study suggests that BIS may reflect changes in cerebral perfusion during CEA.
- Further investigation is required to establish BIS as a quantitative measure for assessing cerebral perfusion adequacy during CEA.
Purpose:
Carotid endarterectomy (CEA) is an established surgical procedure for the treatment of internal carotid artery stenosis. Stroke is the commonest risk factor during CEA, therefore, cerebral monitoring became essential. Currently the EEG bispectral index (BIS) is used as a monitor of depth of anesthesia and it has showed decreasing trend during cerebral ischemia. We conducted this study to document the changes of the BIS variable during CEA under anesthesia.
Methods:
Ten patients who underwent CEA under general anesthesia were studied. The EEG BIS was measured during the perioperative period where five phases were identified: (A) before induction of anesthesia, (B) before clamping of ICA, (C) during clamping of ICA, (D) after declamping of ICA and (E) during the recovery from anesthesia.
Results:
The age ranged between 53-69 yr. The mean values of the BIS were 91.4 +/- 5.6, 59.6 +/- 18.7, 44.3 +/- 6.8, 54.7 +/- 8.3 and 72.1 +/- 12.4 during A, B, C, D and E phases respectively with statistical significant low values during B, C, D and E phases versus phase A.
Conclusion:
The decreasing trend of the EEG BIS was shown during ICA clamping and whether this is an important quantitative variable to determine the adequacy of cerebral perfusion during CEA yet to be further studied.
