Brazilian Journal of Anesthesiology
https://app.periodikos.com.br/journal/rba/article/doi/10.1590/S0034-70942004000300002
Brazilian Journal of Anesthesiology
Scientific Article

Entropia: um novo método de mensuração da profundidade da anestesia. Estudo comparativo com o índice bispectral na avaliação clínica da intubação traqueal com sevoflurano

Entropy: a new method of measuring depth of anesthesia. Comparative study with bispectral index during clinical evaluation in tracheal intubation of patients anesthetized with sevoflurane

Rogean Rodrigues Nunes

http://dx.doi.org/10.1590/S0034-70942004000300002 Braz J Anesthesiol, vol.54, n3, p.289-302, 2004
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Resumo

JUSTIFICATIVA E OBJETIVOS: Entropia espectral, um novo método de análise do EEG, baseado na quantificação do caos do EEG, foi desenvolvido para monitorização da profundidade anestésica. Ele separa a monitorização em dois tipos de análise: entropia de estado (SE), que inclui sinais de baixa freqüência (< 32 Hz) e entropia de resposta (RE), que inclui sinais com freqüência até 47 Hz. O objetivo deste estudo foi comparar os valores de entropia com os do BIS e respostas sub-corticais à intubação orotraqueal, em pacientes submetidos à anestesia geral com sevoflurano. MÉTODO: Participaram do estudo 36 pacientes com idades entre 20 e 44 anos, ASA I, distribuídos em quatro grupos de nove, submetidos à intubação orotraqueal (IOT). Em todos os grupos, a anestesia foi induzida com sevoflurano, associado ou não ao fentanil, de acordo com o seguinte: (G1 = sevoflurano e 2,5 µg.kg-1 de fentanil; G2 = sevoflurano e 5 µg.kg-1 de fentanil; G3 = sevoflurano e 7,5 µg.kg-1 de fentanil e G4 = sevoflurano e solução fisiológica). Foram avaliados os seguintes parâmetros: PAS, PAD, FC, BIS, SE, RE, concentração expirada do sevoflurano (CE) e resposta motora à IOT em três momentos: M1 = imediatamente antes da indução; M2 = imediatamente antes da intubação traqueal e M3 = um minuto após a intubação traqueal. RESULTADOS: Os valores de BIS e SE variaram de maneira linear em todos os grupos, com diferenças significativas entre M2 e M3 nos grupos G1 e G4, tendo ambos (BIS e SE) apresentado valores acima dos limítrofes entre consciência e inconsciência no momento M3 do G4. Em relação ao RE, apenas o G3 não mostrou variações estatisticamente significativas entre os momentos M2 e M3. As variações hemodinâmicas não ultrapassaram valores clinicamente significativos, exceto elevações da FC no G4 entre os momentos M1 e M3 (p < 0,05%). No G1, 66% dos pacientes reagiram as manobras de IOT e 100% no grupo G4. CONCLUSÕES: Este estudo indica que o sevoflurano isoladamente, associado a 2,5 µg.kg-1 ou 5 µg.kg-1 de fentanil, não bloqueia efetivamente as respostas dos componentes cortical e sub-cortical do SNC, sendo a dose de 7,5 µg.kg-1 a melhor associação ao sevoflurano para controle destes componentes anestésicos.

Palavras-chave

ANALGÉSICOS, ANALGÉSICOS, ANESTÉSICOS, ANESTÉSICOS, MONITORIZAÇÃO, MONITORIZAÇÃO, MONITORIZAÇÃO

Abstract

BACKGROUND AND OBJECTIVES: Spectral entropy, a new EEG analysis method based on the quantification of EEG chaos, was developed to monitor anesthetic depth. The spectral entropy involves two distinct types of analysis: state entropy (SE), which includes low frequency signals (< 32 Hz), and response entropy (RE), which includes signals up to 47 Hz. This study aimed at comparing entropy-derived values to BIS-derived values and sub-cortical (autonomic and somatic) responses recorded during tracheal intubation in patients submitted to general anesthesia with sevoflurane. METHODS: Participated in this study 36 patients ASA I, aged 20 to 44 years, assigned to four groups (G1-G4) of nine patients submitted to tracheal intubation (TI). In all groups anesthesia was induced with sevoflurane, associated or not to fentanyl, according to the following regimens: G1 = sevoflurane plus 2.5 µg.kg-1 fentanyl; G2 = sevoflurane plus 5 µg.kg-1 fentanyl; G3 = sevoflurane plus 7.5 µg.kg-1 fentanyl; and G4 = sevoflurane plus saline solution. The following parameters were monitored: SBP, DBP, HR, BIS, SE, RE, sevoflurane expired concentration (EC) and motor response to TI at three moments: M1 = immediately before induction; M2 = immediately before tracheal intubation and M3 = one minute after tracheal intubation. RESULTS: BIS and SE values have linearly varied in all groups, with significant differences between M2 and M3 for Groups 1 and 4. At M3, BIS and SE values in G4 were above those for the threshold between consciousness and unconsciousness. Hemodynamic changes were not clinically significant, with the exception of HR increase between M1 and M3 for G4 (p < 0.05%). In G1, 66% of patients have reacted to TI maneuvers as compared to 100% in G4. CONCLUSIONS: Our findings suggest that sevoflurane alone or in association with 2.5 µg.kg-1 or 5 µg.kg-1 fentanyl does not effectively block CNS cortical and subcortical components responses during tracheal intubation, being sevoflurane plus 7.5 µg.kg-1 fentanyl the best association to control anesthetic components.

Keywords

ANALGESICS, ANALGESICS, ANESTHETICS, ANESTHETICS, MONITORING, MONITORING, MONITORING

References

Viertio-Oja HE, Drachman RN, Merilainen PT. New method to determine depth of anesthesia from EEG measurements. J Clin Monit Comp. 2000;16:60.

Vila P, Canet J, Muñoz S. Entropy: a new anesthetic depth monitor. Comparative study with BIS in the clinical setting. Eur J Anaesth. 2003;20(30):A-91.

Doi M, Gajraj RJ, Mantzaridis H. Relationship between calculated blood concentration of propofol and electrophysiological variables during emergence from anaesthesia: comparison of bispectral index, spectral edge frequency, median frequency and auditory evoked potential index. Br J Anaesth. 1997;78:180-184.

Nishiyama T, Higashizawa T, Bito H. Which laryngoscope is the most stressful in laryngoscopy; Macintosh, Miller, or McCoy?. Masui. 1997;46:1519-1524.

Ko SH, Kim DC, Han YJ. Small-dose fentanyl: optimal time of injection for blunting the circulatory responses to tracheal intubation. Anesth Analg. 1998;86:658-661.

Yli-Hankala A, Vakkauri A, Hoymork S. EEG entropy monitoring decreases propofol consumption and shortens early recovery times. Eur J Anesth. 2003;20(30):A-98.

Shannonn CE. A mathematical theory of communication. Bell Syst Tech J. 1948;27:379-423.

Stein-Ross ML. Theoretical electroencephalogram stationary spectrum for a white-noise-driven cortex: evidence for a general anesthetic-induced phase transition. Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 1999;60:7299-7311.

Quiroga RQ, Arnhold J, Lehnertz K. Kulback-Leibler and renormalized entropies: applications to electroencephalograms of epilepsy patients. Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 2000;62:8380-8386.

Johnson RW, Shore JE. Which is the better entropy expression for speech processing: -S logS or logS?. IEEE Acoust Speech Signal Proc. 1984;32:129-137.

Lader MH, Mathews AM. Electromyographic studies of tension. J Psychosom Res. 1971;15:479-486.

Rosen L, Lunn JN. Consciousness and Awareness and Pain in General Anaesthesia. 1987:89-98.

Dement W, Kleitman N. The relation of eye movements during sleep to dream activity: an objective method for the study of dreaming. J Exp Psychol. 1957;53:339-346.

Edmonds HL, Triantafillou T, Tsueda I. Comparison of frontalis and hypothenar EMG responses to vecuronium. Anesthesiology. 1985;63:A324.

Edmonds HL, Couture LJ, Stolzy SL. Quantitative surface electromyography in anesthesia and critical care. Int J Clin Monit Comput. 1986;3:135-145.

Edmonds HL, Paloheimo M. Computerized monitoring of the EMG and EEG during anesthesia: An evaluation of the anesthesia and brain activity monitor. Int J Clin Monit Comput. 1985;1:201-210.

Watt RC, Hameroff SR, Cork RC. Spontaneous EMG monitoring for anesthetic depth assessment. Proceeding of the Association of Advanced Medical Instrumentation. 1985;20:92.

Mathews DM, Kumaran KR, Neuman GG. Bispectral index-derived facial electromyography-guided fentanyl tritation in the opiate-exposed patient. Anesth Analg. 2003;96:1062-1064.

Kern SE, David PJ, Dezaire BS. Assessing the facial EMG as an indicator of response to noxious stimuli in anesthetized volunteers. ASA Meeting Abstracts. 1999:A594.

Shander A, Qin F, Bennett H. Prediction of postoperative analgesic requirements by facial alectromyography during simultaneous BIS monitoring. Eur J Anaesthesiol. 2001;18(^s21):130.

Lennon RL, Hosking MP, Daube JR. Effect of partial neuromuscular blockade on intraoperative electromyography in patients undergoing resection of acoustic neuromas. Anesth Analg. 1992;75:729-733.

Dutton RC, Smith WD, Bennett HL. Craniofacial electromyogram activation response: another indicator of anesthetic depth. J Clin Monit Comput. 1998;14:5-17.

Zalunardo MP, Zollinger A, Spahn DR. Effects of intravenous and oral clonidine on hemodynamic and plasma: catecholamine response due to endotracheal intubation. J Clin Anesth. 1997;9:143-147.

Randell T, Seppala T, Lindgren L. Isoflurane in nitrous oxide and oxygen increases plasma concentrations of noradrenaline but attenuates the pressor response to intubation. Acta Anaesthesiol Scand. 1991;35:600-605.

Mi WD, Sakai T, Takahashi S. Haemodynamic and electroencephalograph responses to intubationduring induction with propofol or propofol/fentanil. Can J Anaesth. 1998;45:19-22.

Billard V, Moulla F, Bourgain JL. Haemodynamic response to induction and intubation: Propofol/fentanil interaction. Anesthesiology. 1994;81:1384-1393.

Macleod AD, Maycock E. Awareness during anaesthesia and post traumatic stress disorder. Anaesth Intensive Care. 1992;20:378-382.

Vernon JM, Lang E, Sebel PS. Prediction of movement using bispectral electroencephalographic analysis during propofol/alfentanil or isoflurane/alfentanil anesthesia. Anesth Analg. 1995;80:780-785.

Nunes RR. Componentes da atividade anestésica: uma nova visão. Rev Bras Anestesiol. 2003;53:145-149.

Rampil IJ, Mason P, Singh H. Anesthetic potency (MAC) is independent of forebrain structures in the rat. Anesthesiology. 1993;78:707-712.

Rampil IJ. Anesthetic potency is not altered after hypothermic spinal cord transection in rats. Anesthesiology. 1994;80:606-610.

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