[Usefulness of Bispectral Index (BIS) monitoring for early detection of cerebral hypoperfusions]

Abstract

Objectives: The goal of the study was to assess whether clinically significant cerebral hypoperfusion in awake patients would be associated with some alterations in the values of the bispectral index (BIS) monitoring.

Study design: Observational study.

Population and methods: We monitored the BIS during endovascular carotid artery occlusion testing in awake patients.

Results: Twenty-eight patients were included. Twenty-one adequately tolerated the procedure. Their BIS value remained stable throughout the procedure. Four patients had poor angiographic tolerance, but no clinical symptoms. Their BIS value slightly decreased during the test (minimal BIS: 83 [79-87]). Three patients had poor clinical and angiographic tolerance of the occlusion. They all experienced an immediate and dramatic decrease in their BIS value (minimal BIS: ipsilateral to clamping: 50 [45-60]; contralateral to clamping: 48 [45-52]). In all patients, the clinical symptoms and the BIS normalized after deflating the occlusion balloon.

Conclusion: In awake patients, the observed values of the BIS monitoring seem to be associated with clinically relevant cerebral hypoperfusion.

Keywords: Bispectral index; Cerebral hypoperfusion; Cerebral ischemia; Hypoperfusion cérébrale; Index bispectral; Ischémie cérébrale.