Effects of cardiopulmonary bypass and hypothermia on electroencephalographic variables

We studied the effects of hypothermia and cardiopulmonary bypass (CPB) on four depth of anaesthesia monitors; spectral edge frequency (SEF), median frequency (MF), bispectral index (BIS) and auditory evoked potential index (AEPIndex) in 12 patients during uneventful cardiac anaesthesia. Each variable was recorded simultaneously at 10 periods during anaesthesia. All four variables were not affected by the transition to CPB. During hypothermia, values of AEPIndex, MF and SEF were tightly distributed but values of BIS were very variable and overlapped with those before induction of anaesthesia. The variability decreased during rewarming. The values of AEPIndex throughout the anaesthesia never overlapped with those before induction of anaesthesia. The AEPIndex was the most stable and reliable as a depth of anaesthesia monitor among the four variables in cardiac bypass surgery.

[1]  J. Peacock,et al.  Pharmacokinetics of an infusion of propofol during cardiac surgery. , 1990, British journal of anaesthesia.

[2]  C. Kalkman,et al.  Electroencephalographic Characteristics of Emergence from Propofol/Sufentanil Total Intravenous Anesthesia , 1995, Anesthesia and analgesia.

[3]  U Finsterer,et al.  Spectral edge frequency of the electroencephalogram to monitor "depth" of anaesthesia with isoflurane or propofol. , 1996, British journal of anaesthesia.

[4]  M. White,et al.  Postoperative analgesia using a computerised infusion of alfentanil following aortic bifurcation graft surgery , 1992, International journal of clinical monitoring and computing.

[5]  K. Leslie,et al.  Propofol Blood Concentration and the Bispectral Index Predict Suppression of Learning During Propofol/Epidural Anesthesia in Volunteers , 1995, Anesthesia and analgesia.

[6]  E. Blair.  A PHYSIOLOGIC CLASSIFICATION OF CLINICAL HYPOTHERMIA. , 1965, Surgery.

[7]  E Pöppel,et al.  Effects of increasing doses of alfentanil, fentanyl and morphine on mid-latency auditory evoked potentials. , 1993, British journal of anaesthesia.

[8]  K. Leslie,et al.  Prediction of Movement during Propofol/Nitrous Oxide Anesthesia: Performance of Concentration, Electroencephalographic, Pupillary, and Hemodynamic Indicators , 1996, Anesthesiology.

[9]  G N Kenny,et al.  Auditory evoked potential index: a quantitative measure of changes in auditory evoked potentials during general anaesthesia , 1997, Anaesthesia.

[10]  C. Doré,et al.  Effect of propofol on the auditory evoked response and oesophageal contractility. , 1989, British journal of anaesthesia.

[11]  E. Kochs,et al.  Electrophysiological Monitoring and Mild Hypothermia , 1995, Journal of neurosurgical anesthesiology.

[12]  M. White,et al.  Effective concentration 50 for propofol with and without 67% nitrous oxide , 1993, Acta anaesthesiologica Scandinavica.

[13]  E. L. Wright,et al.  Propofol—fentanyl anaesthesia for coronary artery surgery and cardiopulmonary bypass , 1989, Anaesthesia.

[14]  H. Schwilden,et al.  Closed-loop feedback control of propofol anaesthesia by quantitative EEG analysis in humans. , 1989, British journal of anaesthesia.

[15]  D. Chassard,et al.  Auditory evoked potentials during propofol anaesthesia in man. , 1989, British journal of anaesthesia.

[16]  D. Hett,et al.  Effect of temperature and cardiopulmonary bypass on the auditory evoked response. , 1995, British journal of anaesthesia.

[17]  P. Sebel,et al.  Prediction of Movement Using Bispectral Electroencephalographic Analysis During Propofol/Alfentanil or Isoflurane/Alfentanil Anesthesia , 1995, Anesthesia and analgesia.

[18]  P. Rosenberg,et al.  Propofol sequestration within the extracorporeal circuit , 1994, Canadian journal of anaesthesia = Journal canadien d'anesthesie.

[19]  N R Webster,et al.  Auditory evoked response and awareness: a study in volunteers at sub-MAC concentrations of isoflurane. , 1992, British journal of anaesthesia.

[20]  G Bashein,et al.  Electroencephalography during surgery with cardiopulmonary bypass and hypothermia. , 1992, Anesthesiology.

[21]  O. Markand,et al.  Monitoring of multimodality evoked potentials during open heart surgery under hypothermia. , 1984, Electroencephalography and clinical neurophysiology.

[22]  H. Mantzaridis,et al.  CLOSED-LOOP CONTROL OF ANESTHESIA , 1992 .

[23]  G N Kenny,et al.  Relationship between calculated blood concentration of propofol and electrophysiological variables during emergence from anaesthesia: comparison of bispectral index, spectral edge frequency, median frequency and auditory evoked potential index. , 1997, British journal of anaesthesia.

[24]  W J Levy,et al.  Quantitative Analysis of EEG Changes during Hypothermia , 1984, Anesthesiology.

[25]  E. Sabo,et al.  Awareness detection during caesarean section under general anaesthesia using EEG spectrum analysis. , 1996, Canadian journal of anaesthesia = Journal canadien d'anesthesie.

[26]  G N Kenny,et al.  Middle latency auditory evoked potentials during repeated transitions from consciousness to unconsciousness , 1996, Anaesthesia.

[27]  M. White,et al.  A portable target controlled propofol infusion system , 1992, International journal of clinical monitoring and computing.

[28]  G. Hempelmann,et al.  Spectral analysis of the EEG during hypothermic cardiopulmonary bypass , 1987, Acta anaesthesiologica Scandinavica.

[29]  L. Kearse,et al.  Bispectral Analysis of the Electroencephalogram Correlates with Patient Movement to Skin Incision during Propofol/Nitrous Oxide Anesthesia , 1994, Anesthesiology.