The depth of anaesthesia is affected by the age factor in the interpretation of EEG information. Only by fully considering the influence of the age factor can we accurately grasp the depth of anaesthesia.

In the process of general anesthesia, the reliable judgment of the depth of anesthesia has always been the focus of anesthesiologists.In recent decades, researchers have discovered that it is possible to monitor the effects of anesthesia using electroencephalography (EEG), so the information has come to be used to guide anesthesia management.The indicators derived from electroencephalogram (EEG) that can be used to judge the depth of anesthesia during general anesthesia, such as spectral edge frequency, burst inhibition rate, median power frequency, etc., were successively born. Thereafter, commercial instruments for monitoring the depth of anesthesia, such as EEG dual-frequency index, entropy module, Narcotrend index, etc., were also widely used in clinical practice.Although the anesthesia measurements or instrument has many advantages, but the use of these indicators are not considering the factors of age, and have been well documented for general anesthesia electroencephalography (eeg) of different ages is different, this means that in different age groups using the same monitoring indicators will lead to the judgment of anesthesia depth is larger error.Therefore, age should be considered in the process of monitoring the depth of clinical anesthesia, and appropriate indexes should be selected according to different ages to monitor the depth of anesthesia.However, it has not been thoroughly studied which indexes can be used to monitor the depth of anesthesia in each age group and how to conduct reasonable monitoring.Therefore, it is necessary to explore the monitoring indexes of depth of anesthesia in different age groups and the most appropriate monitoring program.

The purpose of this study was to validate EEG indicators that can monitor the depth of anesthesia at different ages, including basic EEG power spectrum parameters and processed parameters, and to explore whether there is an optimal protocol for monitoring the depth of anesthesia at different ages.In order to facilitate the clinical selection of patients of different age groups to monitor the depth of anesthesia, the factor of age is considered so as to take individual monitoring.Finally, it can accurately judge the depth of anesthesia and accurately use the anesthetic drugs.

Inclusion Criteria:

1. ASA Ⅰ ~ Ⅲ level
2. 18 to 100 years
3. BMI 19 ~ 30 kg/m squared
4. Patients without intracranial surgery

Exclusion Criteria:

1. nervous system diseases, abnormal EEG, old cerebral infarction, the use of drugs affecting the nervous system;
2. coronary heart disease, hypertension without regular treatment or poor control;
3. The oxygen partial pressure and calcium ion levels were abnormal before anesthesia induction;
4. History of alcohol abuse.