Bispectral Index Monitoring in the Intensive Care Unit Provides More Signal Than Noise

Abstract

The bispectral index (BIS) is processed electroencephalographic technology used in concert with clinical evaluations to objectively evaluate a patient's level of consciousness and probability of recall. Although the BIS has been extensively studied in the operating room setting, differences in patient populations, goals of treatment, and the environments themselves necessitate the development of BIS data specific to the intensive care unit. Data have evolved over the last several years, but for many reasons, the results and conclusions have varied. Yet within the data are important consistencies that help define the usefulness of BIS in patients who cannot be evaluated with subjective assessment tools such as the Sedation-Agitation Scale or the Richmond Agitation-Sedation Scale. Some of these patients cannot be evaluated with such tools because they lack motor responsiveness due to therapeutic paralysis or because they are receiving deep sedation. Bispectral index scores that are higher than expected in clinically sedated patients can often be traced to electromyographic activity or to the possibility of inadequate sedation and analgesia. The BIS must not be regarded as the sole indicator of level of consciousness, but should be used as part of an integrated approach to the evaluation of carefully selected patients with critical illness.

Anesthetic Management of a Patient With Charcot-Marie-Tooth Disease

“…Bispectral index value would elevate, at least in part because of electromyographic artifact, and moving the head commonly results in elevated electromyographic activity. 14 We could manage this case using assessment of the Ramsay sedation score and tried to do moderate sedation. In addition, we prepared for basic and advanced life support for potential emergencies with the family physician's cooperation.…”

The α2-Adrenoceptor Agonist Dexmedetomidine in Current Sedation Practice

“…БСИ является экспертным методом оценки гипнотического компонента общей анестезии и до настоящего времени не имеет широкого распространения в практике ОРИТ [41][42][43]. В полной мере это относится и к другим вари антам ЭЭГ мониторинга седации.…”

Sedierung und Analgesie auf der Intensivstation: Physiologie und Anwendung

“…Ein Grund dafür sind wahrscheinlich Signalüberlagerungen mit dem Elektromyogramm, welche zu falsch hohen Werten führen können [73]. Andererseits kann der BIS bei Patienten herangezogen werden, die aufgrund von Muskelrelaxierung einer Evaluierung durch Sedierungsscores nicht zugäng-lich sind [74]. Für eine detaillierte Zusammenfassung des BIS auf der IBS wird auf den Review von LeBlanc et al verwiesen [73].…”