Why is it reasonable to monitor the EEG during anaesthesia?
- Advantages and benefits of computer-based EEG monitoring -
What is an EEG?
EEG ist the shortcut of “electroencephalogram”. An EEG is a record of the electrical activity of the brain. For an EEG recording special electrodes are attached to the scalp. They transfer the EEG signals to an electroencephalograph, which displays the EEG curves and can be used for data analysis and storage. The EEG is used for the evaluation of brain function.
What are the advantages of EEG monitoring in anaesthesia?
Many drugs given during anaesthesia or sedation affect the brain function in a characteristic way. This can be observed as accompanying changes of the EEG. Therefore it is useful to record the EEG and to analyse it with computer-based methods. Among the benefits are:
- Adjusting the depth of hypnosis (sleep):
Monitoring the EEG continuously helps in assessing the patient`s depth of hypnosis (sleep). The individualised dosing of anesthetics is supported. Unnecessarily long stays in the recovery room, als well as in the intensive care unit for prolonged ventilation after surgery, can be avoided.
- Early detection of potentially hazardous situations:
Unwanted conditions which might compromise the patient, as a lack of the oxgen supply to the brain or the presence of epileptiform EEG activity, can be detected at an early stage.
Which patients benefit most from EEG monitoring?
Particularly children and older people benefit from the gentle anaesthesia with EEG monitoring. Finding the optimum dosage of anaesthetics in children is difficult. Many drugs have no or only limited approval for use in children. Often scaled down adult doses are used. Therefore the risk of inadequate dosing is increased. In many older patients the dose requirements are reduced, many suffer from concurrent diseases and have a frail physical condition.
Nevertheless, EEG monitoring makes sense in patients of any age, because a wide interindividual variability in the dose requirements of anaesthetic drugs exists. Computer-based EEG monitoring helps in finding the adequate dose and contributes to patient safety.