Generality
Coma, or comatose state, is a state of unconsciousness, from which the one who falls into it cannot be awakened; this condition - characterized by the lack of response to painful stimuli, changes in light and sounds - undermines the sleep-wake cycle and makes any voluntary action impossible.
The severity of a coma and its mode of onset depend on the triggering causes.
Generally and unless the patient does not wake up, the actual state of coma has a limited duration in time, which varies between 4 and 8 weeks. After that, it evolves either in a vegetative state or in a state of minimal consciousness.
The transition from coma to the vegetative state or to that of minimal consciousness may or may not lead to a progressive improvement in the patient's health conditions.
The improvements deriving from the exit from the state of coma are unpredictable, can be more or less rapid and depend on the severity of the brain damage that originally caused the comatose state.
In its early stages, the hospitalization of a comatose person takes place in the intensive care unit; therefore, when the patient's condition has stabilized to a certain degree, it takes place in the ward.
What is coma?
Coma is a state of unconsciousness, from which whoever falls into it cannot be awakened; this condition involves the lack of response to painful stimuli, changes in light and sounds, causes the sleep-wake cycle to skip and, finally, makes any voluntary action impossible.
A person who falls into a coma is called a "comatose person". The comatose adjective is also valid associated with the word "state"; comatose state and coma are synonymous.
COMA AND PHARMACOLOGICAL COMA: ARE THEY THE SAME?
Coma and pharmacological coma are two distinct situations, which should be clarified right from the start of this article.
While coma is a state of pathological unconsciousness, unwanted and indicative of a serious health condition, pharmacological coma is a state of unconsciousness induced voluntarily by doctors, to facilitate recovery from traumatic situations, to protect the brain from a deficiency of oxygen and to reduce sensitivity to pain, during very delicate surgery.
Also known as induced coma or artificial coma, pharmacological coma is achieved with controlled doses of barbiturates, benzodiazepines, or propofol, in addition to opioid analgesics (eg morphine).
ORIGIN OF THE NAME
The term "coma" derives from the Greek word "koma” (κῶμα), which means "deep sleep".
Causes
The reasons why a person can go into a coma are numerous.
Possible causes of coma include:
- Poisoning from abuse / overdose of drugs, hard drugs, harmful substances or alcohol. According to reliable medical investigations, 40 cases of coma out of 100 (therefore 40%) are due to pharmacological poisoning.
- Severe metabolic abnormalities;
- Diseases of the central nervous system at an advanced stage;
- The stroke and the cerebral hernia;
- Severe brain trauma;
- The hypothermia;
- L "hypoglycemia;
- L "severe hypercapnia;
- The eclampsia.
WHEN DOES A PERSON COME INTO COMA?
In the "human brain, there are two nerve components whose correct functioning is essential for maintaining the state of consciousness: the cerebral cortex, in which the so-called gray matter resides, and a structure of the brainstem, called the reticular activation system (RAS ).
The entry into a coma by an individual takes place when one or both of the aforementioned nerve components (ie the cerebral cortex and / or RAS) are damaged.
How drug abuse causes coma and what effects it causes
An "improper intake of drugs damages the so-called reticular activation system (RAS), which, at this point, stops working properly.
Before leading to a coma, the failure of RAS due to a "drug intoxication involves: a" sensitive alteration of heart rhythm and blood pressure, irregular breathing and profuse sweating.
Features
The severity of the coma and the modalities of onset depend on the triggering causes.
For example, taking into consideration only the modalities of onset, coma resulting from hypoglycemia or hypercapnia includes a number of previous symptoms, including: agitation, confusion, progressive dulling and stupor; conversely, coma resulting from a head injury or a Subarachnoid hemorrhagic stroke (subarachnoid hemorrhage) is instantaneous.
The modalities of onset of coma represent an important diagnostic data, which helps doctors to understand what may have triggered the comatose state.
HOW TO ESTIMATE THE SEVERITY OF A COMA?
There are various scales of measurement to estimate the severity of a coma. The most famous and most widely used measurement scale today is the so-called Glasgow Coma Scale (GCS scale). The GCS scale includes a range of values ranging from a minimum of 3 - a value that represents deep coma - to a maximum of 15 - a value that represents maximum consciousness.
The parameters considered by the GCS scale, to evaluate the severity of a coma, are three: the opening of the eyes, the motor response to a certain command and the verbal response to a certain vocal stimulus. Each of these parameters corresponds to a numerical interval (in English score), which indicates its severity.
To understand:
- The eye opening presents one score ranging from 1 to 4. 1 (one) indicates complete absence of eye opening; it is the most severe level. 4 (four), instead indicates spontaneous eye opening; equates to normality.
Intermediate values correspond to intermediate situations. - The motor response to a given command presents one score ranging from 1 to 6. 1 (one) signals complete absence of motor response to any command; it is the most severe level. 6 (six), on the other hand, signals maximum motor obedience to any command; corresponds to normality.
Values between 1 and 6 represent intermediate situations. - The verbal response to a certain vocal stimulus presents one score ranging from 1 to 5. 1 (one) indicates complete absence of response to any type of verbal stimulus; it is the most severe level. 5 (five), on the other hand, indicates maximum attention, normal language skills and ability to respond to any stimulus of a verbal nature; represents normality.
As in the previous cases, the values included between 1 and 5 are equivalent to intermediate situations.
The estimate of the severity of a coma is the result of the sum of the score assigned to each of the aforementioned parameters. For example, if the opening of the eyes, the motor response to a command, and the verbal response to a voice stimulus each total the minimum (i.e. 1) in a "medical investigation", the coma rating is 3 (the most severe, equivalent to deep coma).
At this point, one last important aspect to clarify is missing: in the GCS scale c "is a threshold value that represents the borderline between the state of coma and the state of consciousness. This value is 8. Therefore, when the sum of the parameters GCS is higher than 8, the individual is more or less conscious; when, on the other hand, the sum of the GCS parameters is equal to or less than 8, the subject is in a more or less deep state of coma.
DURATION OF THE COMA
Unless the person concerned does not wake up, the actual state of coma has a canonical duration of between 4 and 8 weeks. Then it evolves and, based on the severity of the triggering causes, it can become: a vegetative state or a state of minimal consciousness.
A person in a vegetative state is an awake subject unaware of himself and of the environment in which he finds himself; a person in a state of minimal consciousness, on the other hand, is an awake subject who, at times, is also aware.
It is very rare for a state of coma to last longer than 8 weeks. In fact, in the absence of awakening or transition to a vegetative state or a state of minimal consciousness, it is easier for the patient to die.
RECOVERY FROM THE COMA
Recovery from a coma varies from individual to individual. In fact, for some, the entry into the vegetative state or the state of minimal consciousness does not coincide with other improvements or coincides with minimal improvements; for someone else, however, it represents the beginning of a gradual process of restoring normal brain functions (capacity cognitive, motor skills, etc.).
When it occurs, the restoration of normal brain functions can be more or less rapid. The speed of recovery of normal brain functions depends on various factors, including:
- The severity of the cause that caused the brain damage and the consequent coma;
- The age and general health of the patient;
- Duration of coma;
- Skills of doctors and other therapists (eg physiotherapists), who take care of the patient.
HOSPITAL ENVIRONMENTS
People in a coma need medical care that only a hospital stay can provide.
In its early stages, the hospitalization of a comatose person takes place in the intensive care unit. In this phase, the intensive care is fundamental, as the onset of the coma represents the most delicate and most in need of attention from the medical staff.
Subsequently, when the patient's condition has stabilized, the hospital stay is held in the ward. Here, doctors will primarily provide maintenance, recovery and prevention therapies.
Diagnosis
The diagnosis of coma is not only the observation of the comatose state - which is usually a simple observation - but it is also the identification of the triggering causes.
The identification of the causes of coma can also be very complex, so much so as to require the use of various diagnostic tests.
Among the possible diagnostic tests useful for the discovery of the conditions at the origin of a state of coma, there are: physical examination, medical history, CT scan, nuclear magnetic resonance (MRI), electroencephalogram, etc.
The typical steps in the diagnosis of coma and its causes
- Physical examination and evaluation of clinical history;
- Assessment of the state of coma. There are specific tests, which allow doctors to ascertain whether or not an individual is in a coma;
- Search for the damaged brain site, which led to a coma;
- Assessment of the severity of the coma, through the scale Glasgow Coma Scale;
- Analysis of a blood sample of the patient, to understand if the origin of the coma may be a "drug intoxication;
- Analysis of blood levels of glucose (glycemia), calcium (calcium), sodium (sodium), potassium (kalaemia), magnesium (magnesium), phosphate (phosphate), urea and creatinine;
- Brain scans, through CT or nuclear magnetic resonance;
- Monitoring of brain functions, through encephalogram.
Treatment
Doctors and experts in the field of coma have not yet identified a medicine or a particular instrument capable of awakening a person in a comatose state.
Having said this, those in a coma receive numerous treatments, the purpose of which is multiple and varies from safeguarding vital functions - such as breathing or blood circulation - to supplying the body with all the nutrients necessary for the survival and maintenance of a good state of health.
In addition, comatose people need special medical attention, which serves to prevent infectious diseases (primarily aspiration pneumonia) or to prevent problems such as bedsores, atelectasis, etc.
Finally, readers are reminded of the existence of a therapeutic guide for people who have come out of a coma, the aim of which is to help them return to a normal or near-normal life.
HOW DO COMATIOUS SUBJECTS BREATHE?
In comatose subjects, mechanical ventilation through intubation supports breathing.
HOW TO PREVENT ASPIRATION PNEUMONITIS
In the case of a coma, aspiration pneumonia is a complication that can be caused by several factors, including:
- Gastroesophageal reflux, resulting from the prolonged maintenance of a horizontal position;
- The inability to swallow correctly;
- Feeding through a tube.
To prevent the complication in question, the most practiced medical remedies consist of:
- Keeping the patient in a lateral position;
- Aspiration of saliva at regular intervals;
- Parenteral nutrition.
HOW TO PREVENT DECUBITUS SORES
Briefly, pressure sores are lesions that typically appear in people who, forced into immobility for long periods of time, maintain a static position.
Pressure sores are a possible consequence not only of coma, but also of fractured limbs, casts in multiple parts of the body, severe obesity or high-risk pregnancy.
To prevent pressure sores, it is essential:
- Change the position of the bedridden patient every 2-3 hours;
- Use water mattresses, which are more congenial to those forced to long periods of immobility;
- Plan adequate nutrition for the needs of the human body;
- Monitor for conducive conditions, such as diabetes.
THERAPEUTIC GUIDE FOR PEOPLE LEAVING THE COMA
People who wake up from a state of coma need some treatments, which - as anticipated - favor the return to a normal life.
The treatments in question include:
- Physiotherapy, essential to remedy muscle contractures resulting from prolonged immobility;
- Occupational therapy, whose field of application ranges from encouraging the patient's reintegration, in a social context, to adapting the home environment according to the needs of the person who has just awakened from a coma;
- Psychotherapy, the aim of which is to help the patient overcome the early stages of awakening from a comatose state and to accept the irrecoverable incapacities that the brain damage and consequent coma may have caused.
CURIOSITY
On the basis of several scientific studies (in particular, one dating back to 2002), some doctors argue that a particularly suitable treatment in the case of post-cardiac arrest coma would be induced hypothermia.
In medicine, the term hypothermia indicates the lowering of the body temperature below the physiological average.
Prognosis
The prognosis in case of coma varies from patient to patient and depends mainly on the triggering causes, on the state of health the patient was in before entering a comatose state and on the extent of the neurological damage.
Even for the most experienced doctors, any prediction on the evolution and long-term consequences of a coma is somewhat complex.