Low Baseline Bispectral Index of the Electroencephalogram in Patients with Dementia

Abstract

This prospective, controlled, observational study demonstrates that electroencephalogram slowing associated with dementia affects the Bispectral Index of the electroencephalogram. A significant proportion of patients with dementia have a lower than normal "awake" Bispectral Index.

Early postoperative delirium after open-heart cardiac surgery is associated with decreased bispectral EEG and increased cortisol and interleukin-6

“…In agreement with Renna et al [13], we found that the BIS index could predict delirium with a low sensitivity, a high specificity, and an overall good accuracy (Fig. 3).…”

“…In contrast to the low sensitivity, the specificity of the BIS index was high. Based on these and Renna et al's data [13], the overall accuracy of bilateral BIS as a screening tool for postoperative delirium is similar to conventional, quantitative EEG [29]. We demonstrated that increased plasma cortisol levels are related to postoperative delirium after open-heart surgery, which is in line with previous studies [30,31].…”

“…Power analysis, assuming a clinically important difference of 4 mean BIS levels [13] between the two groups (nondelirious and delirious), suggested that 114 patients were required for the study (alpha = 0.05; 1-beta = 0.8).…”

“…Our previous study on the surgical ICU [12] detected decreased cerebral cortical activity in patients during delirium, measured by a time-consuming 16-channel EEG system. Furthermore, investigating the role of monolateral BIS EEG (ASPECT Medical System) in detecting dementia or delirium produced controversial results [13,14]. Up to now, no studies have used the newly available bilateral BIS EEG VISTA Ò to investigate postoperative ICU delirium.…”

How deep is your love: Awareness monitoring during general anesthesia

“…In the case of epidural anesthesia, clinical trials have shown that sedation of such patients requires much smaller MAC of Sevoflurane (0.59% compared to 0.92%) to achieve an adequate BIS It is important to note that among patients with dementia value of BIS index (alertness) is lower than in patients who do not have such pathology 31 . Although BIS represents a useful monitoring for the assessment of anesthesia depth, further studies are necessary in patients with congenital disorders of the central nervous system since BIS can give abnormal responses which do not correspond to the specific stage of anesthesia.…”