Induced hypotension. At the start of the example anaesthesia was being maintained with 60% nitrous oxide in oxygen and 0.5% halothane. At (2) 2% halothane was introduced to produce hypotension. This was followed by an initial rise of amplitude and subsequently a fall. At (7) halothane was withdrawn and this was followed by a gradual recovery of amplitude to its initial level. Throughout the recording frequency shifts were minimal. Mean arterial pressures (mmHg) were (1)=70; (2)=65; (3)=60; (5)=58; (6)=53; (8)=60; (10)=70; (11)=68; (12)=75. The EEG before and during the period of amplitude depression is shown at (4) and (9). The impedance trace indicates at times frequent electrode artefacts. One of these is visible in the second EEG sample as a downward spike deflection.
Reproduced with permission from "The cerebral function analysing monitor: initial clinical experience, application and further development", D E Maynard and J L Jenkinson, Anaesthesia, 1984, Volume 39, pages 678-690.Published by Blackwell Science. http://www.blackwell-science.com/ana
CFAM1 trace. The markers at the top of the amplitude/Hz trace indicate 1 minute intervals. The markers over the EEG trace are 1 second intervals
