Brazilian Journal of Anesthesiology
https://app.periodikos.com.br/journal/rba/article/doi/10.1590/S0034-70942001000500008
Brazilian Journal of Anesthesiology
Miscellaneous

Monitor de profundidade da hipnose. A eletroencefalografia bispectral

Monitoring the adequacy of hipnosis by bispectral index

Pedro Thadeu Galvão Vianna

http://dx.doi.org/10.1590/S0034-70942001000500008 Braz J Anesthesiol, vol.51, n5, p.418-425, 2001
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Resumo

JUSTIFICATIVA E OBJETIVOS: A monitorização da profundidade da hipnose e da anestesia é um ato complexo. A maioria das propostas para monitorizar os níveis adequados da hipnose, durante a anestesia, envolve o EEG usando as ondas do EEG, ou mais recentemente, usando a forma processada. A análise bispectral é o método que permite analisar o EEG nas diferentes fases de freqüências. CONTEÚDO: O EEG processado é iniciado com a conversão do sinal de EEG para a forma digital. O EEG digitalizado pode ser matematicamente transformado pelo processo conhecido como análise de Fourier, que separa o complexo sinal do EEG em vários componentes da onda, ou seja, em cada porção de diferente amplitude, mas cuja soma corresponde à forma original da onda. Com o emprego deste método surgem vários parâmetros. O Índice Bispectral, ou simplesmente BIS (100 - acordado até 0 - isoelétrico), é derivado dos melhores parâmetros (p.ex.: freqüência da borda spectral, freqüência mediana e o "burst supression" ou surto de supressão) que foram avaliados através de análise estatística. CONCLUSÕES: A experiência clínica tem mostrado que o BIS pode predizer uma resposta à incisão da pele durante a anestesia. Entretanto, o BIS não é independente da técnica anestésica usada. Há diferentes respostas, a depender do hipnótico e analgésico empregado.

Palavras-chave

MONITORIZAÇÃO, MONITORIZAÇÃO

Abstract

BACKGROUND AND OBJECTIVES: Monitoring the "depth" of anesthesia is a complex process. Most approaches to monitoring anesthetic adequacy involve EEG waves or, more recently, some EEG processed form. Bispectral analysis is a method which allows for EEG analysis in different frequency phases. CONTENTS: Processed EEG starts with the digitalization of the EEG signal. The digitized EEG can then be mathematically transformed by a process known as Fourier analysis, which divides the complex EEG signal in a number of sine wave components, that is, in each portion of different amplitude, but whose sum corresponds to the original EEG waveform. Many parameters are derived from this method. Bispectral index, or simply BIS (100 = awaken to 0= EEG isoelectric) is derived from the best parameters (e.g. spectral edge frequency, median frequency and burst suppression) which are evaluated by statistical analysis. CONCLUSIONS: Clinical experience has shown that BIS may predict a response to skin incision during anesthesia. However, BIS is not independent of the anesthetic technique. There are different responses depending on which hypnotics or analgesics are used.

Keywords

MONITORING, MONITORING

Referencias

Gibbs FA, Gibbs EL, Lennox WG. Effect on the electroencephalogram of certain drugs which influence nervous activity.. Arch Intern Med. 1937;60:154-166.

Rampil IJ. A primer for EEG signal processing in anesthesia. Anesthesiology. 1998;89:980 -1002.

Schwilden H, Schüttler J, Stoeckl H. Quantitation of the EEG and pharma-codynamic modelling of hypnotic drugs: etomidate as an example. Eur J Anaesth. 1985;2:121-130.

Levy WJ, Shapiro HM, Maruchak G. Automated EEG processing for intraoperative monitoring: a comparison of techniques. Anesthesiology. 1980;53:223-236.

Rampil IJ, Matteo RS. Changes in EEG spectral edge frequency correlate with the hemodynamic response to laryngoscopy and intubation.. Anesthesiology. 1987;67:139-142.

Schwilden H, Stoeckl H. Effective therapeutic infusions produced by closed-loop feedback control of methohexital administration during total intravenous anesthesia with fentanyl. Anesthesiology. 1990;73:225-229.

Barnett TP, Johnson LC, Naitoh P. Bispectrum analysis of electroencephalogram signals during waking and sleeping. Science. 1971;172:401-402.

Rosenblatt M, Van Ness JW. Estimation of the bispectrum.. Ann Math Stat. 1972;36:1120-1136.

Nikias CL, Raghuveer MR. Bispectrum estimation: a digital signal processing framework. IEEE Proc. 1987;75:869-891.

Sigl J, Chamoun N. An introduction to bispectral analysis for the electroencephalogram.. J Clin Monit. 1994;10:392-404.

Glass PSA, Bloom M, Kearse L. Bispectral analysis measures sedation and memory effects of propofol, midazolam, isoflurane, and alfentanil in healthy volunteers. Anesthesiology. 1997;86:836-847.

Dutton RC, Smith WD, Smith NT. The Use of EEG to Predict Movement during Anesthesia, Consciousness, Awareness and Pain em: Rosen M, Lunn JN - General Anaesthesia. 1987:72-82.

Kearse LA, Manberg PJ, de Bros F. Bispectral analysis of the electroencephalogram during induction of anesthesia may predict hemodynamic responses to laryngoscopy and intubation. Electroenceph Clin Neurophl. 1994;90:194-200.

Sebel PS, Bowles SM, Saini V. EEG bispectrum predicts movement during thiopental isoflurane anesthesia.. J Clin Monit. 1995;11:83-91.

Dwyer RC, Rampil IJ, Eger IEI. The electroencephalogram does not predict depth of isoflurane anesthesia.. Anesthesiology. 1994;81:403-409.

Moriaka N, Ozaki M, Matsukawa T. Ketamine causes a paradoxical increase in the bispectral index.. Anesthesiology. 1997;87:A502.

Suzuki M, Edmonds HL, Tsueda K. Ketamine on bispectral index and levels of sedation.. J Clin Monit. 1998;14:373-377.

Sakai T, Singh WD, Kudo T. The effect of ketamine on clinical endpoints of hypnosis and EEG variables during propofol infusion. Acta Anaesthesiol Scand. 1999;43:212-216.

Avramov MN, Badrinath S, Shadrick M. The effect of ketamine on EEG-bispectral index (BIS) during propofol sedation. Anesthesiology. 1997;87:A501.

Barr G, Jakobsson JG, Owall A. Nitrous oxide does not alter bispectral index: study with nitrous oxide as sole agent and as adjunct to i. v. anaesthesia.. Br J Anaesth. 1999;82:827-830.

Kearse LA, Rosow CE, Zaslavsky A. Bispectral analysis of the electroencephalogram predicts conscious processing of information during propofol sedation and hypnosis.. Anesthesiology. 1998;88:25-34.

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