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Introduction
The Narcotrend-Compact M serves the purpose of brain function monitoring and was
developed specifically for use with hypnotically acting drugs in operating rooms,
intensive care units and for clinical research. The Narcotrend-Compact M includes the
Narcotrend-Index, a processed EEG parameter, which may be used as an aid in
monitoring the effects of certain hypnotically acting anesthetic agents.
Under the influence of narcotics/anesthetics, the EEG reveals very characteristic
changes. The EEG can therefore be used to assess the hypnotic status of the patient.
Based on a large number of parameters derived from the EEG, multivariate statistical
methods are used to carry out an automatic classification of the EEG on a scale ranging
from stage A (conscious) to stage F (very deep hypnosis). This division of stages is
refined by means of an EEG index (100 = conscious, 0 = very deep hypnosis).
Fig. 1:
EEG index, EEG stages und typical EEG patterns
The automatic classifications in variation of time constitute the cerebrogram. This
cerebrogram provides the user with important information on the hypnotic status of the
patient in the course of the recording.
An impedance check is available in order to ensure good signal quality. During an on-
going recording, the program carries out automatic electrode tests at regular intervals.
In addition, extensive algorithms for automatic detection of artifacts have been
implemented in the program.
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The automatic assessment is not allowed to be the sole criterion of a
narcosis or sedation controlling function. With respect to the dosing of
narcotics and sedatives, the overall clinical findings must be taken into
account.