Closed-loop feedback control of propofol anaesthesia by quantitative EEG analysis in humans
Schwilden, H.; Stoeckel, H.; Schüttler, J.
British Journal of Anaesthesia 62(3): 290-296
1989
ISSN/ISBN: 0007-0912 PMID: 2784685 Document Number: 326807
Propofol was administered for 2 h to 11 volunteers by an adaptive feedback control algorithm based on quantitative EEG analysis. Median EEG frequency served as the control variable. The range 2-3 Hz was chosen as the target range from control. During the feedback period, volunteers did not response to commands and eyelash reflex was abolished. An average median frequency of 2.5 (SD 0.3) Hz was obtained by administering propofol 1452 (262) mg within 2h. Time to recovery was 17.9 (8.0) min. Compared with a study with methohexitone using the same approach, the relative potency of propofol was 0.72. The mean recovery time was less than half that observed after methohexitone.