What is digitized electroencephalogram in Vietnam? Can all patients with anaesthesia and critical care apply digital EEG?

Main Content

• How to evaluate the effect of anesthetic on the brain and change the level of sedation?
• Is digitized EEG on all patients and of all ages?
• How to perform digitized EEG?

How to evaluate the effect of anesthetic on the brain and change the level of sedation?

Pursuant to Section I of the Guidelines promulgated together with Decision 1571/QD-BYT in 2022 of the Ministry of Health, there are the following instructions:

- Digitized EEG is a common name that refers to the means of electroencephalographic analysis of a patient's frontal lobe and converts it into numerical data (usually from 1 to 100). These means help to assess the effect of anesthetic on the brain (anesthesia) and objectively monitor changes in the patient's level of sedation or sleep. These are means of applying technology to replace the previous subjective clinical assessment.

- Biodiversity monitoring allows assessment of changes in anesthetic needs of each patient; at different times of the surgical process on a patient; helps to detect overdose or insufficient dose of anesthetic, especially when the clinical signs used to assess anesthesia are confounded due to many reasons such as when receiving drug combinations (muscle relaxants, beta-blockers... ), or comorbidities (such as liver failure, renal failure, heart failure...), or hemodynamic instability during surgery.

- Biodiversity helps to control anesthesia and optimize the dose of anesthetic and sedative needed for each patient. Therefore, bioengineering helps save anesthetics and medical costs; safe treatment, helping patients recover quickly. Another special feature is that SEA helps maintain stable anesthesia, reducing the rate of patients waking up during general anesthesia.

- The technical process of monitoring anesthesia and sedation by BSH includes techniques for monitoring anesthesia by BIS, monitoring anesthesia by Entropy, or means of equivalent principles.

Accordingly, the evaluation of the effect of anesthesia on the brain and monitoring of changes in the patient's sedation or sleep is done through digital electroencephalography.

What is digitized electroencephalogram in Vietnam? Can all patients do digital EEG?

Is digitized EEG on all patients and of all ages?

According to the instructions in Sections II and III of the Guidelines issued together with Decision 1571/QD-BYT in 2022 of the Ministry of Health, the contents are as follows:

“II. POINT

Monitoring anesthesia, sedation in Anesthesia and Intensive Care.

III. CONTRAINDICATIONS

1. Absolute contraindications:

- Patient refuses

- Injury to the skin of the electrode area

2. Do not use for the following cases (due to the lack of information on the reliability of the Biodiversity value)

- Children under 6 months old.

- The patient is anesthetized with: ketamine, nitrous oxide (NO).

- The patient has hypothermia

- Patients with dementia"

Thus, not all digitized EEG methods are applicable to all patients. Cases such as children under 6 months of age, patients under anesthesia with: ketamine, nitrous oxide (NO), hypothermic patients and dementia patients will not use EEG.

How to perform digitized EEG?

Pursuant to subsection 3, section V of the Guidelines promulgated together with Decision 1571/QD-BYT in 2022 of the Ministry of Health, has guided the implementation of digitized EEG as follows:

- The patient is in supine position, exposing the forehead and temples on the side with the DNSH electrode attached

- Use alcohol cotton to wipe the forehead and temples before sticking the DSH electrode.

- Glue the bioreactor: follow the manufacturer's instructions for each electrode selected.

- Connect the bioreactor electrode to the biosynthetic monitor (monitoring).

- Check signal quality.

- Monitor the indicators on the biotech screen and make clinical decisions.

In addition, section VI of the Guidelines issued together with Decision 1571/QD-BYT in 2022 of the Ministry of Health also has the following content on digital EEG monitoring:

"BECAUSE. FOLLOW

1. Monitor displayed on the screen of the Biodiversity monitor (monitoring), including the following indicators:

a. Value of Biodiversity at the time of observation:

BSE values ​​range from 0 (very deep sleep, EEG - EEG is isoelectric) to 100 (fully awake, EEG asynchronous and no flat segment):

For BIS - Entropy:

+ A range from 90 to 100 indicates a state of alertness. A range of 60-90 indicates a state of sedation

+ BSE is about 40 - 60 patients in deep enough anesthesia, suitable for maintaining anesthesia for surgery

+ CSF below 40 indicates deep anesthesia

+ SVT below 20 is too deep anesthesia, manifesting changes in brain electrical image burst - extinguished (appears before loss of brain electrical activity).

b. Trend graph of biotech values ​​over time.

c. Raw EEG waveforms in real time.

d. Signal quality indicators such as EMG (electromyography), SQI (singal quality index)

-- EMG is an electromechanical signal, displayed on the screen from 27 - 80 dB (when installed). When EMG is significant, the BSH can be misaligned. EMG below 30 dB did not affect the biomarker index. EMG above 55 dB will affect the biofuel index. Monitor EMG to assess the accuracy of BSH, combined with the clinical status of the patient to adjust the appropriate anesthesia.

- SQI: quality index, value from 0 - 100%, or display corresponding to 5 bars each is 20%. If the EMG signal overwhelms the EEG signal, the SQI will decrease rapidly.

+ SQI 20% (signal bar 2 bars) of the SQI value, reliable

+ SQI < 20% (signal bar shows only 1 bar) of SQI value, do not display DNSH index

+ Intermittent electrical noise for 45 seconds, the SQI will decrease and the SQI will not be displayed.

e. Alarm signal.

2. Guidelines for handling according to the Gurman decision diagram:

Accordingly, the technique of using and monitoring the digitized EEG method is performed according to the content of the instructions above.