What happens to your body when it is completely anesthetized? – ElSol.com.ar – Diario de Mendoza, Argentina

When people receive an anesthetic, they seem to lose consciousness or, at least, stop reacting to their environment. Is consciousness completely lost during anesthesia or does consciousness persist in the brain, but in an altered state?

Scientists from the University of Turku and the Hospital District of Southwest Finland showed he loses completely during general anesthesia, although the person no longer reacts to his environment.

However, according to these works, experiences and thoughts similar to dreams can still float in consciousness despite anesthesia. Thus, the brain can record speech and try to decipher words, but the person will not understand them or remember them consciously.

Thus, it is considered that the state of unconsciousness induced by anesthetics may be similar to natural sleep. While they sleep, people dream and the brain unconsciously observes what is happening and the stimuli in their environment, so that the anesthesia looks more like normal sleep than it was thought, according to authors.

The study, in collaboration with researchers at the University of Michigan, Ann Arbor, and the University of California, Irvine, USA, is a joint project between the research group of the badistant professor of pharmacology and anesthesiologist Harry Scheinin, who studied the mechanisms of anesthesia, and the research group by psychology professor Antti Revonsuo, who badyzed human consciousness and the brain from the point of view of philosophy and psychology.

This joint research project entitled "The Conscious Mind: Integrating Subjective Phenomenology with Objective Measurements" investigated the neural mechanisms of human consciousness and, for this, controlled electroencephalogram (EEG) anesthetics and positron emission tomography (PET). Their findings were published in four different publications in the July issues of the two leading journals of anesthesiology.

Effects of Anesthesia

In the first part of the study, volunteer participants in good health They were anesthetized with dexmedetomidine or propofol. The drugs were administered with computer controlled infusions controlled by the target until the subject had barely lost its reactivity

From this state, subjects could wake up with slight tremors or a loud voice. without changing the infusion. Immediately after the subjects regained their responsiveness, they were asked if they had experienced anything during the period of anesthesia.

Almost all participants reported sleep-like experiences that sometimes mixed with reality, says the author. Professor Revonsuo

The subjects were told sentences in Finnish during anesthesia, with the intention of checking whether the subjects detected and understood words or complete sentences under anesthesia.

Responses on the EEG have shown that the brain can not tell the difference between normal sentences and strange sentences, such as "the night sky filled with clear tomatoes," when it is under anesthesia. Moreover, after waking up, they did not remember the prayers they had heard. The results were the same with both anesthetics, as reported by the principal investigator, badistant professor Katja Valli.

Subjects also heard unpleasant sounds during anesthesia. After waking, these sounds came back to play and, surprisingly, they reacted faster to those sounds than to the new sounds they had never heard before.

In other words, the brain can process sounds and words even if the subject does not remember them. After Contrary to common belief, anesthesia does not require a total loss of consciousness because it simply disconnects the patient from the environment, says Dr. Scheinin.

The project also investigated the effects of four different anesthetics on regional metabolism. brain glucose with PET images. The results alleviated concerns about the possible adverse effects of dexmedetomidine on the relationship between cerebral blood flow and metabolism. In the future, the project will further badyze the badociation between cerebral blood flow or metabolism and the state of consciousness