JOURNAL HOME CME HOME THIS MONTH PAST ISSUES ETOC COLLECTIONS AUTHORS REVIEWERS EDITORIAL BOARD FEEDBACK RSS HELP
		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

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 ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (6) Citing Articles via Google Scholar Google Scholar Articles by Scheufler, K. M. Articles by Priebe, H.-J. Search for Related Content PubMed PubMed Citation Articles by Scheufler, K. M. Articles by Priebe, H.-J.

---

TECHNOLOGY, COMPUTING, AND SIMULATION

The Modifying Effects of Stimulation Pattern and Propofol Plasma Concentration on Motor-Evoked Potentials

Kai M. Scheufler, MD^*, Peter C. Reinacher, MD, Winfried Blumrich, MD, Josef Zentner, MD^*, and Hans-Joachim Priebe, MD

*Department of Neurosurgery, University Hospital, Freiburg, Germany; Department of Neurosurgery, University Hospital, Aachen, Germany; and Department of Anesthesiology, University Hospital, Freiburg, Germany

Address correspondence and reprint requests to Kai M. Scheufler, MD, Abt. Allgemeine Neurochirurgie, Universitätsklinikum Freiburg, Breisacher Str. 64, D-79106 Freiburg, Germany. Address e-mail to scheufle{at}nz11.ukl.uni-freiburg.de.

The quality of intraoperative motor-evoked potentials (MEPs) largely depends on the stimulation pattern and anesthetic technique. Further improvement in intraoperative MEP recording requires exact knowledge of the modifying effects of each of these factors. Accordingly, we designed this study to characterize the modifying effect of different stimulation patterns during different propofol target plasma concentrations (PTPCs) on intraoperatively recorded transcranial electrical MEPs. In 12 patients undergoing craniotomy, stimulation patterns (300–500 V; 100–1000 Hz; 1–5 stimuli) were varied randomly at different PTPCs (2, 4, and 6 µg/mL). Remifentanil was administered unchanged at 0.2 µg · kg^–1 · min^–1. MEPs were recorded from the thenar and hypothenar muscles. Analysis of MEPs was blinded to the PTPC. Three-way analysis of variance revealed significant main effects of increasing stimulation intensity, frequency, and number of stimuli on MEP amplitude (P < 0.05). Maximum MEP amplitudes and recording success rates were observed with three or more stimuli delivered at 1000 Hz and 150 V. A significant main effect of PTPC (2 vs 4 and 6 µg/mL) on MEP amplitude was observed at the thenar recording site only (P < 0.05). An amplitude ratio calculated from corresponding MEPs evoked by double and quadruple stimulation proved to be insensitive to changes in PTPC. In conclusion, MEP characteristics varied significantly in response to changes in stimulation pattern and less to changes in PTPC.

This article has been cited by other articles:

				H.-J. Priebe Aneurysmal subarachnoid haemorrhage and the anaesthetist Br. J. Anaesth., July 1, 2007; 99(1): 102 - 118. [Abstract] [Full Text] [PDF]

				P. C. Reinacher, H.-J. Priebe, W. Blumrich, J. Zentner, and K. M. Scheufler The effects of stimulation pattern and sevoflurane concentration on intraoperative motor-evoked potentials. Anesth. Analg., March 1, 2006; 102(3): 888 - 895. [Abstract] [Full Text] [PDF]

				A. S. Das and K. S. Babu Informed awareness: is it ethical? Anesth. Analg., March 1, 2006; 102(3): 967 - 968. [Full Text] [PDF]

Anesthesia & Analgesia® is published for the International Anesthesia Research Society® by Lippincott Williams & Wilkins with the assistance of Stanford University Libraries' HighWire Press®. Copyright 2006 by the International Anesthesia Research Society. Online ISSN: 1526-7598   Print ISSN: 0003-2999