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Measuring depth of sedation in intensive care patients with the electroencephalographic Narcotrend Index

Published online by Cambridge University Press:  01 February 2008

F. Weber*
Affiliation:
Sophia Children’s Hospital, Erasmus University Medical Center Rotterdam, Department of Anesthesiology, Rotterdam, The Netherlands
M. Steinberger
Affiliation:
University Hospital Regensburg, Department of Anaesthesia, Franz-JosefStrauss-Allee, Regensburg, Germany
M. Ritzka
Affiliation:
University of Regensburg, Department of Neurology, Universitätsstraße, Regensburg, Germany
C. Prasser
Affiliation:
University Hospital Regensburg, Department of Anaesthesia, Franz-JosefStrauss-Allee, Regensburg, Germany
T. Bein
Affiliation:
University Hospital Regensburg, Department of Anaesthesia, Franz-JosefStrauss-Allee, Regensburg, Germany
*
Correspondence to: Frank Weber, Department of Anaesthesiology, Erasmus University Medical Center Rotterdam – Sophia Children’s Hospital, P.O. Box 2060, 3000CB Rotterdam, The Netherlands. E-mail: [email protected]; Tel: +31 463 1145; Fax: +31 463 6804
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Summary

Background and objective

The electroencephalographic Narcotrend Index was evaluated as a measure of sedation in mechanically ventilated intensive care unit patients. Narcotrend Index and conventional electroencephalography parameter values were compared to the Richmond Agitation-Sedation Scale and a simplified three-level sedation scale.

Methods

In all, 100 mechanically ventilated patients, admitted to the cardiac surgical intensive care unit after open-heart surgery, were enrolled in this prospective observational study. The Narcotrend Index was recorded while patients were either sedated by propofol infusion or without sedative medication while being weaned off the ventilator. Clinical assessment of the patients’ level of sedation was performed by means of the Richmond Agitation-Sedation Scale by a single observer who was blinded to the Narcotrend Index.

Results

With the six-level Richmond Agitation-Sedation Scale, the prediction probability (PK) for the Narcotrend Index (0.81) was better than for all other electroencephalography parameters (P < 0.01) except for relative power in the β band (PK 0.75). Using the three-level sedation scale instead, PK values for the Narcotrend Index (0.88) and all electroencephalography parameters improved (P < 0.01), and the Narcotrend Index was now superior to all electroencephalography parameters. Narcotrend Index values were distributed among the various sedation levels with significant overlap.

Conclusion

When used for assessment of propofol sedation in postsurgical cardiac intensive care unit patients, the Narcotrend Index can distinguish between very light and deep sedation. With respect to differentiation between light and moderate or moderate and deep sedation, the Narcotrend Index was not reliable in this study.

Type
Original Article
Copyright
Copyright © European Society of Anaesthesiology 2007

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Footnotes

a

Formerly: Department of Anaesthesia, University Hospital Regensburg, Franz-JosefStrauss-Allee 11, 93053 Regensburg, Germany.

References

1.JrNasraway, SA, Jacobi, J, Murray, MJ et al. . Sedation, analgesia, and neuromuscular blockade of the critically ill adult: revised clinical practice guidelines for 2002. Crit Care Med 2002; 30: 117118.CrossRefGoogle ScholarPubMed
2.Riker, RR, Fraser, GL, Simmons, LE et al. . Validating the Sedation-Agitation Scale with the Bispectral Index and Visual Analog Scale in adult ICU patients after cardiac surgery. Intensive Care Med 2001; 27: 853858.CrossRefGoogle ScholarPubMed
3.Sessler, CN, Gosnell, MS, Grap, MJ et al. . The Richmond Agitation-Sedation Scale: validity and reliability in adult intensive care unit patients. Am J Respir and Crit Care Med 2002; 166: 13381344.CrossRefGoogle ScholarPubMed
4.Kreuer, S, Wilhelm, W. The Narcotrend monitor. Best Pract Res Clin Anaesthesiol 2006; 20: 111119.CrossRefGoogle ScholarPubMed
5.Schultz, A, Grouven, U, Beger, FA et al. . The Narcotrend Index: classification algorithm, correlation with propofol effect-site concentrations, and comparison with spectral parameters. Biomed Tech 2004; 49: 3842.CrossRefGoogle ScholarPubMed
6.Kreuer, S, Bruhn, J, Larsen, R et al. . Comparability of Narcotrend Index and bispectral index during propofol anaesthesia. Br J Anaesth 2004; 93: 235240.CrossRefGoogle ScholarPubMed
7.Kreuer, S, Biedler, A, Larsen, R et al. . Narcotrend monitoring allows faster emergence and a reduction of drug consumption in propofol–remifentanil anesthesia. Anesthesiology 2003; 99: 3441.CrossRefGoogle Scholar
8.Kreuer, S, Biedler, A, Larsen, R et al. . The Narcotrend – a new EEG monitor designed to measure the depth of anaesthesia. A comparison with bispectral index monitoring during propofol–remifentanil anaesthesia [in German]. Anaesthesist 2001; 50: 921925.CrossRefGoogle ScholarPubMed
9.Kreuer, S, Molter, G, Biedler, A et al. . Narcotrend stages and end-tidal desflurane concentrations. An investigation during recovery from desflurane/remifentanil anaesthesia [in German]. Anaesthesist 2002; 51: 800804.CrossRefGoogle ScholarPubMed
10.Wilhelm, W, Kreuer S Larsen, R. Narcotrend EEG monitoring during total intravenous anaesthesia in 4630 patients [in German]. Anaesthesist 2002; 51: 980988.CrossRefGoogle Scholar
11.Russell, IF. The Narcotrend ‘depth of anaesthesia’ monitor cannot reliably detect consciousness during general anaesthesia: an investigation using the isolated forearm technique. Br J Anaesth 2006; 96: 346352.CrossRefGoogle ScholarPubMed
12.Schneider, G, Kochs, EF, Horn, B et al. . Narcotrend does not adequately detect the transition between awareness and unconsciousness in surgical patients. Anesthesiology 2004; 101: 11051111.CrossRefGoogle Scholar
13.Smith, WD, Dutton RC Smith, NT. Measuring the performance of anesthetic depth indicators. Anesthesiology 1996; 84: 3851.CrossRefGoogle ScholarPubMed
14.Schultz, B, Grouven U Schultz, A. Automatic classification algorithms of the EEG monitor Narcotrend for routinely recorded EEG data from general anaesthesia: a validation study. Biomed Tech 2002; 47: 913.CrossRefGoogle ScholarPubMed
15.Schultz, B, Kreuer, S, Wilhelm, W et al. . The Narcotrend Monitor: development and interpretation algorithms [in German]. Anaesthesist 2003; 52: 11431148.CrossRefGoogle ScholarPubMed
16.Roustan, JP, Valette, S, Aubas, P et al. . Can electroencephalographic analysis be used to determine sedation levels in critically ill patients? Anesth Analg 2005; 101: 11411151.CrossRefGoogle ScholarPubMed
17.JrNasraway, SA. The Bispectral Index: expanded performance for everyday use in the intensive care unit? Crit Care Med 2005; 33: 685687.CrossRefGoogle ScholarPubMed
18.Schneider, G, Heglmeier, S, Schneider, J et al. . Patient State Index (PSI) measures depth of sedation in intensive care patients. Intensive Care Med 2004; 30: 213216.CrossRefGoogle ScholarPubMed
19.Chisholm, CJ, Zurica, J, Mironov, D et al. . Comparison of electrophysiologic monitors with clinical assessment of level of sedation. Mayo Clin Proc 2006; 81: 4652.CrossRefGoogle ScholarPubMed
20.Weber Jensen, E, Rodriguez, B, Litvan, H. P K value does depend on the fineness of the observer scale [Letter]. Acta Anaesthesiol Scand 2005; 49: 427.CrossRefGoogle ScholarPubMed