In order to ascertain the subconscious state of general anesthesia and prevent anesthesia awakening, researchers have found a better way to measure consciousness
because when surgery is required for general anesthesia, first use drugs to make the patient lose consciousness. Perform endotracheal intubation, the anesthesia machine assists breathing while inhaling anesthetics to control the depth and time of anesthesia, and then assists intravenous drugs to maintain anesthesia, until the operation is completed, then stop the inhalation anesthetics, gradually recover, and pull out the endotracheal tube when consciousness is basically recovered Guan, this is the general process of general anesthesia. In the United States alone, millions of people receive general anesthesia each year, but it is not easy to judge whether they are truly unconscious.
When the surgical operation was undergoing general paralysis, the patient's motor nerves were paralyzed but the patient remained conscious. At this time, in the eyes of outsiders, the patient will not make any response to the outside world, but in fact his consciousness is clear. If the operation is performed in this state, every cut, ligation, puncture, medicine application... the patient will feel it clearly. The frightening thing is that about 60,000 people in the United States alone suffer from such nightmarish operations every year.
A small percentage of these patients regained some consciousness during medical procedures, but a new study of brain activity that represents consciousness can prevent potential trauma. It can also help people in a coma and scientists work to determine which parts of the brain can claim to be the key to consciousness.
In the past 100 years, people have proven that in the unconscious state like sleep, these slow electric wave activities in the brain exist. But these signals may not be suitable for us to use. In many cases (using different anesthetics, comatose patients, brain injury patients or other clinical conditions),There may also be high frequency activity.
Researchers at the University of Wisconsin-Madison at the National Primate Research Center in Wisconsin recorded the electrical activity of about 1,000 neurons around 100 brain locations in a pair of monkeys in several states of consciousness: Drugs Induction of anesthesia, light sleep, waking up at rest, and awakening from anesthetized to awake state by electrical stimulation at a point deep in the brain (researchers described this process in 2020).
Using data spanning multiple brain regions and different states of consciousness, we can combine all the signals traditionally related to consciousness (including how fast or slow the rhythm of different regions of the brain is) Putting it together, more calculation indicators are used to describe the complexity of these signals and how the signals in different regions interact.
In order to filter out the characteristics that best indicate whether the monkey is conscious or unconscious, the researchers used machine learning. They gave a large amount of data to the computer, told the computer which state of consciousness produced each pattern of brain activity, and asked which areas of the computer's brain and electrical activity patterns are most similar to consciousness.
The results of the study point to areas other than the frontal cortex. This part of the brain is usually used to monitor the general anesthesia state of human patients, and it is most likely to appear unconscious for a long time. Slow fluctuations in typical activities.
Now clinically, anesthesiologists can place electrodes on the patient’s forehead. We believe that the back of the head is more important for these electrodes, because we have learned that the back and deep areas of the brain are more predictive of consciousness than the front. status. Although both low-frequency and high-frequency activities can appear in the unconscious state, complexity can best indicate a clear mind.
In the past, people thought that knowledge during general anesthesia was a rare complication of general anesthesia, but with the in-depth study of intraoperative knowledge, especially implicit memory, and the continuous development of psychology test methods, general anesthesia patients
A more precise measurement of anesthetized patients is a possible result of a new discovery. The researchers are part of a collaborative project supported by the National Science Foundation to apply knowledge of key brain regions.
In addition to detecting the state of consciousness, these ideas can improve the treatment results of patients with disorders of consciousness can use the knowledge we have learned to optimize the current pattern through precise brain stimulation to help people in a coma state to maintain continuous Level of consciousness.
References: Mohsen Afrasiabi et al. Consciousness depends on integration between parietal cortex, striatum, and thalamus. Cell Systems . March 16, 2021 .
