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Comas

Coma — the deep oppression of the central nervous system which is shown a loss of consciousness, loss of reaction to external irritants and disorder of regulation of the vital functions of an organism.
The coma does not represent an independent disease, and belongs to complications and quite often serves as heavy manifestation of an end-stage of various diseases.
At children owing to anatomo-physiological features of an organism of a coma arise more often than at adults.

Etiology.

 Comas at children's age arise for various reasons. Intracranial pathological processes, endogenous and exogenous intoxications, a hypoxia of disbolism etc. can cause them. And age specifics of influence of this or that etiological factor are observed. So, the intracranial birth trauma, a syndrome of respiratory frustration, sepsis, pneumonia, metabolic disturbances most often bring in the neonatality period to a coma. At early children's age the predominating role belongs to infectious diseases, exogenous poisonings, inflammations of a brain and its covers, respiratory and cardiovascular insufficiency of various genesis. At children of more advanced age usually infectious toxicosis, a cherepnomozgovy injury, exogenous poisonings, endocrine diseases, metabolic disturbances are the reasons of a coma at pathology of a liver and kidneys.

Pathogeny.

Is the cornerstone of a pathogeny of a coma of any etiology as it was already noted, defeat of TsNS, and depends on extent of this defeat in most cases the forecast of the coma. So, the loss of consciousness is caused by lowering of spontaneous activity of bark and a number of subcrustal educations, and also disturbance of korkovopodkorkovy relationship. It is caused or oppression of the ascending activating influences of a reticular formation on a cerebral cortex as a result of defeat of a brain trunk (especially a mesencephalon), either extensive functional or structural disturbances in cerebral hemispheres, or that and another in a combination. The state is aggravated with frustration of a gemoa of a likvorodinamika, hypostasis and swelling of a brain, increase of intracranial pressure, hypoxemic and metabolic disturbances of nervous tissue. Under the influence of these factors providing a brain with nutrients and oxygen is broken, fermental systems of nervous cells are damaged that leads to power starvation of a brain. Sensitivity of various departments of a brain to the damaging influences is not identical. Young structures difficult phylogenetic are more vulnerable, and less difficult "ancient" educations are rather steady against influence of harmful factors.

Pathological anatomy.

 The coma does not cause in a brain of any specific morphological changes. At it signs of a basic disease prevail. In case of primary defeats of TsNS changes carry inflammatory, tumoral, traumatic or other character. Depth of structural disturbances in a brain can vary from obmennodistrofichesky shifts before the expressed morphological changes. The last are shown by a trichangiectasia with stazy blood, a necrobiosis of vessels, dot hemorrhages, dystrophy and acute swelling of neurocytes and glial cells.

Classification.

 Depending on localization of primary center of defeat distinguish cerebral, or neurologic, a coma, resulting from primary defeat of the central nervous system, and somatogenic, caused by pathology of internals or exogenous intoxication with development of secondary metabolic encephalopathy. Neurologic a coma are in turn subdivided on vascular, traumatic, tumoral and a coma at epilepsy. Among somatogenic the lump is allocated a coma with hydropenia (diabetic, uraemic, adrenal, thyrocardiac, gipokhloremichesky) and without hydropenia (hypoglycemic, hepatic, anemic, hypo - and hyper thermal electroshock, ekzotoksichesky a coma).

Clinic.

Development of a coma is preceded, as a rule, by an oglushennost, somnolence, a delirious syndrome and a sopor.
Oglushennost — the initial phase of oppression of consciousness which is characterized by slackness, an adynamia, drowsiness, orientation disturbance elements, decrease in mental activity.
Somnolence — deeper extent of oppression of consciousness which is shown a state, similar to a dream from which the child can be brought by means of external influences. At the same time purposive movements remain and the patient is capable to answer questions in monosyllables.
Delirious syndrome — the frustration of consciousness which is followed by hallucinations, psychomotor excitement and nonsense.
Sopor — oppression of consciousness with preservation of reactions in the form of coordinate protective movements to strong sound, light and painful irritants in the absence of verbal contact.
Coma — full switching off of consciousness.
On expressiveness of clinical manifestations N. K. Bogolepov distinguishes 4 severity of comas.

  1. degree — an easy coma. The consciousness is lost, there are no reactions even on strong light and sound irritants. On strong pain stimulations reaction is kept in the form of involuntary movements, a suffering mimicry, reflexes from mucous membranes are caused, the food is swallowed automatically, pupils are narrowed, but well react to light. The muscle tone is lowered, sukhozhilnonadkostnichny reflexes are recovered, skin — are lowered. Breath and cordial activity are not broken. The urination is involuntary, but there is its delay.
  2. degree — the expressed coma. Reactions to strong irritants are absent. Pupils are narrowed, their reaction to light dies away. Corneal and gag reflexes are kept. Muscular dystonia, a gormetoniya are noted, pathological pyramidal and protective reflexes appear. There come disorders of breath in the form of pathological forms (stertorozny, Cheyn — Stokes, Kussmaul). Cordial activity (a low pulse, lowering of arterial pressure, cyanosis) is broken.
  3. degree — a deep coma. The vital reflex acts die away. There are no reactions to painful irritants of various modality. Eyeballs are fixed in median situation or make the floating movements. Pupils are expanded, do not react to light, corneal reflexes are absent. Swallowing is broken. There comes the atony of muscles. Tendinous and periosteal reflexes are not caused. Protective reflexes are absent or are altered (their zone is expanded — necks, persons are caused from a stomach), and in certain cases become complicated (possibly bending of one and extension of other leg). Breath discontinuous is also carried out with participation of auxiliary muscles, the hemodynamics is sharply broken, cordial activity is oppressed, there come the collapse, cyanosis, a hypothermia.
  4. degree — ultraboundary, or terminal, a coma. Spontaneous breath stops and progressiruyushche arterial pressure falls. Life is supported only by means of the artificial ventilation of the lungs and medicamentous therapy stimulating cardiovascular activity.

It should be noted that neurosurgeons mark out only 3 severity of a coma: moderate, deep and ultraboundary.

However, as K. Ozhilvi considers, not determination of severity of a coma, and the correct assessment and accurate reflection in the history of an illness of extent of loss of consciousness is important. For this purpose it is possible to apply irritants, various on a modality: a hail, stirring, effleurage in the footsteps of, pat on the person, pricks of extremities, pressing in the field of supraorbital cutting, compression of a lobe of an ear or bottom edge of a nasal partition. The specified influences are made symmetrically on both sides and in the absence of reaction on one of them help to reveal focal injuries of a brain.

Clinical criterion

Nature of reaction

Assessment in points

A. Opening of eyes

involuntary

4

on a hail

3

on pain

2

no

1

B. Motor reactions

are carried out on command

6

pushing away of an irritant

5

otdergivany extremities

4

abnormal bending

3

abnormal extension

2

no

1

For an objective assessment of weight of a coma use certain scales where each symptom is estimated in points which sum characterizes extent of loss of consciousness. The scale of Glasgow offered G. Teasdale and V. by Jennet (1974) is most convenient for practical application.
Clinical criterion                     Nature of reaction              in points


B. Speech reaction

correct speech

5

the confused speech

4

dumb shouts

2

no

1

G. Reaction of pupils to light

normal

5

slowed down

4

uneven

3

anisocoria

2

no

1

D. Reactions of cranial nerves

all are kept: are absent:

5

ciliary reflex

4

lid reflex

3

okulotsefalny reflex ("doll eyes")

2

reflex from bifurcation of a trachea

1

no

5

E. Spasms

focal

4

generalized passing

3

generalized continuous

2

full relaxation

1

Zh. Spontaneous breath

normal

5

periodic

4

central hyperventilation arhythmic or hypoventilation

3

 

2

apnoea

1

The greatest difficulties arise at an assessment of degree of a loss of consciousness at newborns. In such cases special attention is paid on nature of spontaneous physical activity of the child, on intensity of suction and swallowing.

Diagnosis.

At inspection of the patient who is in a coma before carrying out neurologic survey it is necessary to estimate extent of disturbance of breath and if necessary to provide adequate lung ventilation of the patient, otherwise it is possible to miss time, and it is fraught with death.
Correctly exact and full anamnestic data help to predict the coma reason. When collecting the anamnesis it is necessary to ask carefully parents or persons accompanying the patient on his previous diseases, contacts with infectious patients, to establish sequence of development of symptoms of an illness and their communication with this or that pathogenic factor (exogenous influences, an injury etc.).
At diagnosis cerebral whom in the course of neurologic inspection it is necessary to reveal: 1) signs of increase of intracranial pressure; 2) focal symptoms of damage of a brain; 3) meningeal symptoms.
Quite often to establish signs of focal damage of a brain at the patient who is in a deep coma very difficult. The following diagnostic characters can play a certain role in the solution of this task. It is necessary to remember that in a condition of a deep coma in the paralyzed extremity a muscle tone lower, the hand of the patient raised by the doctor falls on the party of paresis quicker, than on the opposite side, foot on a paretichny extremity is more rotirovana of a knaruzha, mouth corner on the paralyzed party is lowered, the cheek at breath passively is answerable (a symptom of "sail"). Point also unilateral Babinski's reflex or Yanishevsky, an unilaterality of response to the irritating incentives, turn of the head and eyes to focal damage of a brain aside, focal convulsive attacks. An important and terrible symptom of a coma is also the unilateral mydriasis with loss of its photoharmose. It is a precursory symptom of dislocation of mediobazalny departments of a temporal share with their infringement in an opening it is mashed a cerebellum that demands the emergency neurosurgical intervention.
Essential value in diagnosis of increase of intracranial pressure has research of an eyeground, cerebrospinal liquid, Ekho-EG. If on an eyeground signs of stagnation do not come to light if there is no need for the emergency actions and clinical trial is complete, the patient can carry out a diagnostic spinal puncture.
Specification of the neurologic diagnosis is promoted also by results of a X-ray analysis of a skull, an electroencephalography, ekhoentsefaloskopiya, computer tomography of a brain.
In that case when signs of a compression of a brain and its focal defeat, and also symptoms of irritation of a meninx do not come to light, it is necessary to try to establish one of the numerous somatogenic reasons of a coma. To the general signs somatogenic whom, proceeding with hydropenia, anorexia, nausea, diarrhea, a xeroderma and decrease in its turgor, hypotonia of muscles and eyeglobes, tachycardia, increase in maintenance of erythrocytes, hemoglobin, residual nitrogen and crude protein in blood, increase of a hematocrit belong.
In establishment of the diagnosis of a diabetic coma the instruction existence of hyperventilation, a hyperglycemia and glucosuria, acetone in urine help with the anamnesis on a diabetes mellitus, and also an acetone smell from a mouth.
Urea smell from a mouth, the arterial hypertension, a hemorrhagic syndrome, anemia, a hyperazotemia, a hyposthenuria and other changes in urine are signs of an uremic coma.
The combination of an acute vascular collapse to the increased pigmentation of integuments and mucous, a hypopotassemia, a hyponatremia, a hypoglycemia grants the right to assume existence of an adrenal coma.
The thyrocardiac coma at children's age meets seldom and is followed by a tachyarrhythmia, a hyperplasia of a thyroid gland and an exophthalmos.
The Gipokhloremichesky coma can develop after numerous vomiting, a diarrhea, at food toxicoinfections, the wrong use of diuretic means. For it, except the general signs a lump proceeding with hydropenia the low content of chlorides and sodium in blood is characteristic.
The hypoglycemic coma develops at the children having diabetes at insulin overdose, an insulinoma (an insulinprodutsiruyushchy tumor of a pancreas), toxic influence of some medicines (salicylates, antihistamines, guanyl guanidines). At it humidity of skin, profuse sweating, toniko-clonic spasms, meningeal symptoms in the presence of a hypoglycemia are noted.
In case of suspicion on an alcoholic coma at the relevant anamnestic data it is necessary to define a blood alcohol level. However it is necessary to remember that the alcohol smell from a mouth is not a reliable diagnostic character of an alcoholic coma; other pathological process (a cherepnomozgovy injury, an acute disorder of cerebral circulation, a toxic hypoglycemia) can be the reason of a coma.
The hepatic coma is followed by yellowness of integuments, increase in a liver and spleen, high level of bilirubin in blood, change of functional hepatic trials.
The anemic coma develops owing to insufficient blood supply of a brain against clinical and laboratory signs of heavy anemia. This type of a coma is caused by massive blood losses of various origin, aplastic anemia, leukoses. However in the presence of symptoms of hemorrhagic diathesis it is necessary to exclude intracraneal hemorrhage.
The sudden aggravation of symptoms and development of a coma in earlier healthy child in the absence of instructions on a chronic disease of internals, allows to assume poisoning with medicines (sleeping pill, tranquilizers). In this case the coma, deep, similar to a dream, can develop. For specification of its actual reason toxicological research is shown.
Coma, the resulting influences of physical factors (electroshock, hypo - and hyper thermal), as a rule, do not cause diagnostic difficulties as there are anamnestic data on these influences.
Inspection of the patient who is in a coma, especially in case of an ambiguity of its genesis has to include at least the following diagnostic testings: general blood test and urine, determination of content in blood of glucose, urea, crude protein and protein fractions, bilirubin and electrolytes; in urine — glucose, acetone, ketonic bodies; eyeground oftalmoskopiya; according to indications — a spinal puncture, Ekho-EG, toxicological inspection, a computer tomography.

Treatment.

The patients who are in a coma are hospitalized to the intensive care unit where intensive supervision, inspection and controlled treatment which general principles are as follows is provided to them. A priority is maintenance of vital functions (breath, blood circulation). At intoxication whenever possible quickly delete poison from an organism, give antidotes or carry out a hemodialysis. Besides, at a coma causal treatment of a basic disease, haemo circulation recovery, dehydrating therapy with a regidratation (in the absence of an eksikoz), correction of metabolic disturbances, elimination of a hypothermia, antibiotics, vasoprotectives, antioxidants, if necessary — anticonvulsants, and also parenteral food, actions for prevention and treatment of complications of a coma are shown.

 
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