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Unfortunately, the patient cannot be awakened, but he can be kept alive "artificially".
Diagnostic investigations show, in fact, that blood no longer flows to the brain, despite the fact that a "cardiac activity" remains.
The most frequent causes of irreversible coma are:
- Prolonged cardiac arrest (due to lack of oxygen supply to the tissues, haemorrhagic shock, intoxication, etc.);
- Head trauma;
- Severe stroke.
The irreversible coma involves the loss of vegetative functions, which is evident due to the absence of response to strong external stresses, such as painful (nociceptive) or acoustic stimuli, the inability to breathe autonomously, the drop in blood pressure and the decrease body temperature (hypothermia).
The definitive arrest of cerebral activity is evidenced by two flat electroencephalograms (EEG) several hours apart. This condition corresponds in all respects to the death of the patient. For legal reasons, the diagnosis of irreversible coma requires a "careful observation of several hours by a commission of medical specialists, who make use of all clinical data and instrumental supports, to clarify any minimum and theoretical doubt.
Once the doctors have decreed this situation, therefore, there is no possibility of the patient's awakening. In this case, it is possible to consider organ donation.
(or brain death) with persistence of cardiac activity. This condition coincides with the last stage (or degree), more serious and profound than coma; for this reason, irreversible coma is also called "fourth degree coma" or "stage 4 coma".
Did you know that…
Coma - understood as a generic condition of deep and lasting unconsciousness - does not indicate brain death, that is, the irreversible cessation of all brain functions, but it can evolve into this condition.
Irreversible coma corresponds to the deeper state of coma and is characterized by the complete disappearance of signs of brain activity, lack of reflexes and non-autonomous breathing. The individual has no awareness of himself or of the surrounding environment and of the stimuli that come from it. In this pathological condition, however, the heartbeat continues to persist.
The irreversible coma is, therefore, a somewhat artificial situation: the patient needs mechanical breathing which, outside of an intensive therapy, could not last for more than a few minutes.