Different Conditions That Could Result in the Bispectral Index Indicating an Incorrect Hypnotic State

Abstract

Since its introduction in 1996, the Bispectral Index (BIS) has gained increasing popularity in daily anesthesia practice. However, numerous reports have been appearing in the literature of paradoxical BIS changes and inaccurate readings. The purpose of this review is to assess the utility of BIS monitoring through examining the various published reports of all BIS values not coinciding with a clinically judged sedative-hypnotic state, whether arising from an underlying pathophysiology of electroencephalographic (EEG) cerebral function or because of shortcomings in the performance and design of the BIS monitor. High electromyographic activity and electric device interference could create subtle artifact signal pollution without their necessarily being displayed as artifacts. This would be misinterpreted by the BIS algorithm as EEG activity and assigned a spuriously increased BIS value. Numerous clinical conditions that have a direct effect on EEG cerebral function could also directly influence the BIS value.

Automatic administration of propofol and remifentanil guided by the bispectral index during rigid bronchoscopic procedures: a randomized trial

“…3 This observation can be explained by the unique characteristics of anesthesia for rigid bronchoscopic procedures, in particular, a short duration of maintenance (four times less than for routine surgical procedures), and electroencephalogram artefacts caused by inadequate neuromuscular blockade. 13 The dual-loop system and the manual TCI administration performed similarly in the present study with respect to time spent under adequate anesthesia (BIS 40-60 ), emergence time, and precision of the system, as estimated by the parameters proposed by Varvel et al 8 and by the GS, a novel index proposed by our group. 9 The median GS in the manual group was 37 in the present study, while it was 26 in our previous study performed in routine care.…”

BIS and Entropy in the elderly

“…It is possible that, in the patients with a disparity of greater than 20 points in processed EEG indices, one of the monitors was being affected by artifact. A comprehensive review of factors that affect BIS was recently published [23]. Alternatively, the different algorithms may interpret the EEG differently.…”

Efeitos de diferentes frações inspiradas de oxigênio no índice biespectral em cães submetidos à infusão contínua de propofol

“…Em outubro de 1996, a Food and Drug Adminstration (FDA) aprovou o monitor de índice biespectral (BIS) (Dahaba, 2005), desenvolvido a partir de uma variável derivada da análise biespectral do EEG, que possivelmente conseguiria determinar o estado de profundidade anestésica dos pacientes. Esse é um caso especial de análise poliespectral comumente aplicada para caracterizar o eletroencefalograma durante a anestesia (Abke et al, 1996).…”