This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Manberg, P. J. Articles by Kelley, S. D. Search for Related Content PubMed Articles by Manberg, P. J. Articles by Kelley, S. D.

---

LETTER TO THE EDITOR

Cardiopulmonary Bypass Machine Can Interfere with Accuracy of BIS Monitor

Aspect Medical Systems, Inc.; www.BISeducation.com; pmanberg{at}aspectms.com

In Response:

We appreciate Tewari and Skinner (1) reporting the apparent artifact from a cardiopulmonary bypass machine which resulted in unusually high BIS value measurements. As summarized by Dahaba (2), several medical devices have been reported to cause higher than expected BIS values under certain conditions, presumably due to electromechanical artifacts that are not detected correctly by the BIS system. A similar artifact caused by the cardiopulmonary bypass machine has recently been documented in another case report (3), which emphasized that the EEG display from the BIS monitor demonstrated an undulating pattern with the same frequency as the pump head rotations.

These reports serve as important reminders that clinical judgment and correlation with other available clinical assessment and monitoring information should be used when interpreting BIS values. We believe that an appropriate response to a sudden BIS increase should include assessing the current level of surgical stimulation, ensuring that anesthetic dose is sufficient and that anesthetic delivery systems are operating properly as well as examination for potential artifacts (4). Inspection of the EEG display may lead to rapid identification of artifacts influencing the BIS value. Finally, we encourage clinicians to contact the manufacturer when questions regarding product performance arise, to obtain educational support and to facilitate the continuous product improvement process.

REFERENCES

1. Tewari P, Skinner H. Cardiopulmonary bypass machine can interfere with accuracy of BIS monitor. Anesth Analg 2007; 105:534[Free Full Text]
2. Dahaba A. Different conditions that could result in the bispectral index indicating an incorrect hypnotic state. Anesth Analg 2005;101:765–73[Abstract/Free Full Text]
3. Vretzakis G, Dragoumanis C, Argiriadou H, Papaziogas B, Konstantinou F, Tsakiridis K. Inaccuracy of BIS values produced by the cardiopulmonary bypass machine during the operative repair of an aortic dissection. J Cardiothorac Vasc Anesth 2006;20:68–70[Web of Science][Medline]
4. Kelley SD. Monitoring level of consciousness during anesthesia and sedation. Newton, MA: Aspect Medical Systems, 2003

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Manberg, P. J. Articles by Kelley, S. D. Search for Related Content PubMed Articles by Manberg, P. J. Articles by Kelley, S. D.