Effect of sevoflurane/nitrous oxide versus propofol anaesthesia on somatosensory evoked potential monitoring of the spinal cord during surgery to correct scoliosis A.S.W. Ku, Y. Hu, M.G. Irwin, B. Chow, S. Gunawardene, E.E. Tan, K.D.K. Luk British Journal of Anaesthesia Volume 88, Issue 4, Pages 502-507 (April 2002) DOI: 10.1093/bja/88.4.502 Copyright © 2002 British Journal of Anaesthesia Terms and Conditions
Fig 1 The 10–20 international system of EEG electrode placement. Cz′ is located 2 cm posterior to Cz.12 British Journal of Anaesthesia 2002 88, 502-507DOI: (10.1093/bja/88.4.502) Copyright © 2002 British Journal of Anaesthesia Terms and Conditions
Fig 2 An example of the changes in SSEP amplitude and dose plotted on a scatter chart corresponding to time. The upper curve represents the dose changes during surgery. Units are MAC in the sevoflurane group and μg ml−1 in the propofol group. The lower curve shows contemporaneous changes in SSEP amplitude (μV). The dose-increase period was measured from the point when the dose was increased by 30% from the baseline to the time when the SSEP amplitude reached a plateau. The dose-decrease period was measured from the point when the dose returned to baseline to the point when SSEP amplitude had increased to 70% of its baseline value. British Journal of Anaesthesia 2002 88, 502-507DOI: (10.1093/bja/88.4.502) Copyright © 2002 British Journal of Anaesthesia Terms and Conditions