This Article Full Text 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 Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Bell, S. L. Articles by Lutman, M. E. Search for Related Content PubMed PubMed Citation Articles by Bell, S. L. Articles by Lutman, M. E.

---

TECHNOLOGY, COMPUTING, AND SIMULATION

The Auditory Middle Latency Response, Evoked Using Maximum Length Sequences and Chirps, as an Indicator of Adequacy of Anesthesia

Steven L. Bell, BA, MSc, PhD, David C. Smith, BMedSci, BM, BS, DM, FRCA^*, Robert Allen, BSc, PhD, CEng, FIEE, FIMechE, FIPEM^*, and Mark E. Lutman, BSc, MSc, PhD^*

*Institute of Sound and Vibration Research, University of Southampton, Department of Anaesthetics, Southampton General Hospital, Southampton, United Kingdom

Address correspondence to S. L. Bell, BA, MSc, PhD, Institute of Sound and Vibration Research, University of Southampton, Southampton SO17 1BJ, United Kingdom. Address e-mail to slbi{at}svr.soton.ac.uk.

The auditory evoked potential known as the middle latency response (MLR), evoked with regular click stimulation at around 5 Hz, has been suggested as an indicator of adequacy of anesthesia. The MLR is a very small signal embedded in high levels of background noise, so it can take a long time to acquire. However, using a stimulus paradigm of chirps presented in a maximum length sequence, the acquisition of the MLR can be improved compared to using conventional click stimulation. In this pilot study, we investigated this new technique in a clinical environment. Significant changes in MLR amplitude, but not latency, were measured for six of seven subjects in association with changes in responsiveness to command using the isolated forearm technique. The absence of any latency shift differs from other studies of the MLR during anesthesia and highlights the limited understanding of the relationship between anesthesia and the MLR.

This article has been cited by other articles:

				A. Lamas, J. Lopez-Herce, L. Sancho, S. Mencia, A. Carrillo, M. J. Santiago, and V. Martinez Bispectral Index and Middle Latency Auditory Evoked Potentials in Children Younger Than Two-Years-Old Anesth. Analg., February 1, 2008; 106(2): 426 - 432. [Abstract] [Full Text] [PDF]