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Entropy is more resistant to artifacts than bispectral index in brain-dead organ donors

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Abstract

Objective

To evaluate the usefulness of entropy and the bispectral index (BIS) in brain-dead subjects.

Design and setting

A prospective, open, nonselective, observational study in the university hospital.

Patients and participants

16 brain-dead organ donors.

Interventions

Time-domain electroencephalography (EEG), spectral entropy of the EEG, and BIS were recorded during solid organ harvest.

Measurements and results

State entropy differed significantly from 0 (isoelectric EEG) 28%, response entropy 29%, and BIS 68% of the total recorded time. The median values during the operation were state entropy 0.0, response entropy 0.0, and BIS 3.0. In four of 16 organ donors studied the EEG was not isoelectric, and nonreactive rhythmic activity was noted in time-domain EEG. After excluding the results from subjects with persistent residual EEG activity state entropy, response entropy, and BIS values differed from zero 17%, 18%, and 62% of the recorded time, respectively. Median values were 0.0, 0.0, and 2.0 for state entropy, response entropy, and BIS, respectively. The highest index values in entropy and BIS monitoring were recorded without neuromuscular blockade. The main sources of artifacts were electrocauterization, 50-Hz artifact, handling of the donor, ballistocardiography, electromyography, and electrocardiography.

Conclusion

Both entropy and BIS showed nonzero values due to artifacts after brain death diagnosis. BIS was more liable to artifacts than entropy. Neither of these indices are diagnostic tools, and care should be taken when interpreting EEG and EEG-derived indices in the evaluation of brain death.

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References

  1. Gan TJ, Glass PS, Windsor A, Payne F, Rosow C, Sebel P, Manberg P (1997) Bispectral index monitoring allows faster emergence and improved recovery from propofol, alfentanil, and nitrous oxide anesthesia. BIS Utility Study Group. Anesthesiology 87:808–815

    Article  PubMed  CAS  Google Scholar 

  2. Vivien B, Paqueron X, Le Cosquer P, Langeron O, Coriat P, Riou B (2002) Detection of BD onset using the bispectral index in severely comatose patients. Intensive Care Med 28:419–425

    Article  PubMed  Google Scholar 

  3. Vivien B, Di Maria S, Ouattara A, Langeron O, Coriat P, Riou B (2003) Overestimation of Bispectral Index in sedated intensive care unit patients revealed by administration of muscle relaxant. Anesthesiology 99:9–17

    Article  PubMed  Google Scholar 

  4. Inoue S, Kawaguchi M, Sasaoka N, Hirai K, Furuya H (2006) Effects of neuromuscular block on systemic and cerebral hemodynamics and bispectral index during moderate or deep sedation in critically ill patients. Intensive Care Med 32:391–397

    Article  PubMed  Google Scholar 

  5. Freye E, Levy JV (2005) Cerebral monitoring in the operating room and the intensive care unit: an introductory for the clinician and a guide for the novice wanting to open a window to the brain. I. The electroencephalogram. J Clin Monit Comput 19:1–76

    Article  PubMed  Google Scholar 

  6. Goncharova I, McFarland DJ, Vaughan TM, Wolpaw JR (2003) EMG contamination of EEG: spectral and topographical characteristics. Clin Neurophysiol 114:1580–1593

    Article  PubMed  CAS  Google Scholar 

  7. Rampil IJ (1998) A primer for EEG signal processing in anesthesia. Anesthesiology 89:980–1002

    Article  PubMed  CAS  Google Scholar 

  8. Vakkuri A, Yli-Hankala A, Talja P, Mustola S, Tolvanen-Laakso H, Sampson T, Viertiö-Oja H (2004) Time-frequency balanced spectral entropy as a measure of anesthetic drug effect in central nervous system during sevoflurane, propofol, and thiopental anesthesia. Acta Anaesthesiol Scand 48:145–153

    Article  PubMed  CAS  Google Scholar 

  9. Viertiö-Oja H, Maja V, Särkelä M, Talja P, Tenkanen N, Tolvanen-Laakso H, Paloheimo M, Vakkuri A, Yli-Hankala A, Meriläinen P (2004) Description of the Entropy algorithm as applied in the Datex-Ohmeda S/5 Entropy Module. Acta Anaesthesiol Scand 48:154–161

    Article  PubMed  Google Scholar 

  10. White PF, Tang J, Romero GF, Wender RH, Naruse R, Sloninsky A, Kariger R (2006) A comparison of state and response entropy versus bispectral index values during the perioperative period. Anesth Analg 102:160–167

    Article  PubMed  Google Scholar 

  11. Myles PS, Cairo S (2004) Artifact in the bispectral index in a patient with severe ischemic brain injury. Anesth Analg 98:706–707

    Article  PubMed  Google Scholar 

  12. Grigg MM, Kelly MA, Celesia GG, Ghobrial MW, Ross ER (1987) Electroencephalographic activity after BD. Arch Neurol 44:948–954

    PubMed  CAS  Google Scholar 

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Authors and Affiliations

  1. Department of Anesthesiology and Intensive Care Medicine, Helsinki University Hospital, 340, 00029, Helsinki, Finland

    Johanna Wennervirta & Reino Pöyhiä

  2. Department of Clinical Neurophysiology, Helsinki University Hospital, Helsinki, Finland

    Tapani Salmi

  3. Department of Anesthesia and Intensive Care Medicine, Helsinki University Hospital, Jorvi Hospital, Espoo, Finland

    Markku Hynynen

  4. Department of Anesthesia, Tampere University Hospital, and Medical School, University of Tampere, Tampere, Finland

    Arvi Yli-Hankala

  5. Department of Anesthesiology and Intensive Care Medicine, Helsinki University Hospital, Surgical Hospital, Helsinki, Finland

    Anna-Maria Koivusalo & Anne Vakkuri

  6. VTT Technical Research Centre of Finland, Tampere, Finland

    Mark Van Gils

Authors
  1. Johanna Wennervirta
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  2. Tapani Salmi
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  3. Markku Hynynen
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  4. Arvi Yli-Hankala
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  5. Anna-Maria Koivusalo
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  6. Mark Van Gils
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  7. Reino Pöyhiä
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  8. Anne Vakkuri
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Corresponding author

Correspondence to Johanna Wennervirta.

Additional information

This article is discussed in the editorial available at: http://dx.doi.org/10.1007/s00134-006-0430-0

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Wennervirta, J., Salmi, T., Hynynen, M. et al. Entropy is more resistant to artifacts than bispectral index in brain-dead organ donors. Intensive Care Med 33, 133–136 (2007). https://doi.org/10.1007/s00134-006-0429-6

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  • DOI: https://doi.org/10.1007/s00134-006-0429-6

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