Monitoring of Anesthesia by Bispectral Analysis of EEG Signals

Abstract

Background. In intensive care, monitoring the depth of anesthesia during surgical procedures is a key element in the success of the medical operation and postoperative recovery. However, despite the development of anesthesia thanks to technological and pharmacological advances, its side effects such as underdose or overdose of hypnotics remain a major problem. Observation and monitoring must combine clinical observations (loss of consciousness and reactivity) with tools for real-time measurement of changes in the depth of anesthesia. Methodology. In this work, we will develop a noninvasive method for calculating, monitoring, and controlling the depth of general anesthesia during surgery. The objective is to reduce the effects of pharmacological usage of hypnotics and to ensure better quality recovery. Thanks to the overall activity of sets of neurons in the brain, we have developed a BIS technique based on bispectral analysis of the electroencephalographic signal EEG. Discussion. By collecting the electrical voltages from the brain, we distinguish light sleep from deep sleep according to the values of the BIS indicator (ranging from 0 : sleep to 100 : wake) and also control it by acting on the dosage of propofol and sevoflurane. We showed that the BIS value must be maintained during the operation and the anesthesia at a value greater than 60. Conclusion. This study showed that the BIS technology led to an optimization of the anesthetic management, the adequacy of the hypnotic dosage, and a better postoperative recovery.

Multivariate Analysis for the Influence of Ejection Fraction Value on Propofol Anesthesia Induction Requirement and its Pharmacodynamic Properties in Cardiopulmonary Bypass Surgery (Observational Study based on the Clinical Outcomes)

“…The primary outcome in this observational study is the BIS index value where an anesthetist can determine the adequacy of anesthetic to produce unconsciousness without causing a coma (overdose of anesthetic) or awareness (inadequate anesthesia). The method of determining the level of consciousness of anesthetized patients using the BIS spectral index is an effective method based on a systematic review and meta-analysis study (22) , it was a result of BIS spectral index has a very good sensitivity in detecting brain waves such as alpha, beta, theta, delta, and gamma where in general hypnotic anesthetic drugs will produce delta waves (23) . In addition, the BIS index method has also received approval from the FDA to determine the level of consciousness in patients and has excellent sensitivity to propofol when compared to midazolam and sevoflurane (10) .…”

Anestezijos Gylio Monitoravimas Elektroencefalografija Pagrįstomis Sistemomis

“…bispectral index, BIS) [1]. Bispektrinio indekso monitorius apdoroja elektroencefalografinius signalus, kad gautų vertę, išreikštą skaitmenimis, kuri atspindi paciento sąmonės lygį [2]. BIS monitorius renka neapdorotus EEG duomenis per savo jutiklius ir naudoja algoritmą duomenims analizuoti ir interpretuoti.…”

“…BIS reikšmė paprastai laikoma tarp 40-60, kad būtų išvengiama paciento pabudimo ar intraoperacinio sąmoningumo. Tai puiki priemonė užkirsti kelią nepageidaujamiems reiškiniams arba juos sumažinti [2]. Nors BIS monitorius yra viena iš lengviausiai prieinamų EEG paremtų sistemų gydymo įstaigose, tačiau nėra tinkama visais klinikiniais atvejais − dėl skirtumų žievės EEG signaluose, nenaudojamas pediatriniams pacientams [6].…”