A new processed EEG machine, the Lifescan, ®which uses aperiodic analysis, was used to monitor cerebral activity prospectively in twenty-one patients undergoing carotid artery surgery under general anaesthesia. The machine was easy to apply, use and read. Volatile agents caused a bilateral decrease in high frequency activity. Unilateral changes consistent with cerebral ischaemia at the time of carotid cross-clamping were also seen. One such prolonged change was not associated with neurological deficit. A further patient awoke with neurological deficit without displaying Lifescan®evidence of ischaemia. The machine requires further assessment.
ThompsonJ.E.Carotid endarterectomv, 1982 — the state of the art.Br J Surg1983; 70: 371–376.
2.
SundtT.N.The ischaemic tolerance of neural tissue and the need for monitoring and selective shunting during carotid endarterectomy.Stroke1983; 14: 93–98.
3.
MichenfelderJ.D.The assessment of cerebral function.Can Anaesth Soc J1984; 31: 513–515.
4.
GrundyB.L., SandersonA.C., WebsterM.W., RicheyE.T., ProcopioP., KaranjiaP.N.Hemiparesis following carotid endarterectomy: comparison of monitoring methods.Anesthesiology1981; 55: 462–466.
5.
RampilI.J., HolzerJ.A., QuestD.O., RosenbaumS., CorrellJ.W.Prognostic value of computerized EEG analysis during carotid endarterectomy.Anesth Analg1983; 62: 186–192.
DemetrescuM.The aperiodic character of the electroencephalogram (EEG): a new approach to data analysis and condensation.Physiologist1975; 18: 189.
8.
LevyW.J.Processed EEG: A machine and a number are not enough.(Editorial) J Cardiothor Anesth1988; 2: 121–122.
9.
BowdleT.A., RookeG.A., KazmersA.Intraoperative stroke during carotid endarterectomy without a change in the spectral edge frequency of the compressed spectral array.J Cardiothor Anesth1988; 2: 204–206.
10.
BlumeW.T., FergusonG.G., McNeillD.K.Significance of EEG changes at carotid endarterectomy.Stroke1986; 17: 891–897.
11.
BakerD., GluecklichB., WatsonC.W., MarcusE., KamatV., CallowA.D.An evaluation of electroencephalographic monitoring for carotid surgery.Surgery1975; 78: 787–794.
12.
GelbA.W., ManninenP., FergusonG., BlumeW.Cerebral monitoring during carotid endarterectomy: their value in predicting neurological outcome and the influence of anaesthetic agents.Can Anaesth Soc J1985; 32: S82 (Abstract).
13.
Anesthesia for certain types of surgery. In: Year Book of Anesthesia. Eds. MillerR.D., KirbyR.R., OstheimerG.W., RoizenM.F., StoeltingR.K. Ch. 6, pp 195–196. Year Book Medical Publishers, Inc.1987, Chicago.
14.
BlairR.D.G., WaltzA.G.Regional cerebral blood flow during acute ischaemia. Correlation of autoradiographic measurements with observations of cortical microcirculation.Neurology1970; 20: 802–808.
15.
ChiappaK.H., StephanieR., BurkeB.M., YoungR.R.Results of electroencephalographic monitoring during 367 carotid endarterectomies.Stroke1979; 10: 381–388.
16.
EvansW.E., HayesJ.P., WaltkeE.A., VermillionB.D.Optimal cerebral monitoring during carotid endarterectomy: neurologic response under local anesthesia.J Vasc Surg1985; 2: 775–777.
17.
KatznelsonR.D.EEG recording, electrode placement, and aspects of generator localisation. In: Electric Fields of the Brain. Nunes PL, Katznelson RD.Oxford University Press, New York, NY1981; 176–283.
18.
SpackmanT.N., FaustR.J., CucchiaraR.F., SharbroughF.W.A comparison of aperiodic analysis of the EEG with standard EEG and cerebral blood flow for detection of ischemia.Anesthesiology1987; 66: 229–231.
19.
SmithN.T., QuinnM., Dec-SilverH., SanfordT.J.Aperiodic analysis of EEG response to fentanyl and sufentanil anesthesia during open heart surgery.Anesth Analg1983; 62: 284–285. (Abstract).
