Shock

Shock is a collective concept denoting extreme stress tension of homeostasis regulation mechanisms under various primary endogenous and exogenous influences.

Depending on the underlying cause, there are various forms of shock, there are many, there is no single classification. The most popular classification is based on the etiological principle:

1. exogenous pain (traumatic, burn, electrical injury, etc.);
2. endogenous-painful (cardiogenic, nephrogenic, abdominal, etc.);
3. humoral (hemotransfusion or post-hemotransfusion, hemolytic, insulin, anaphylactic, toxic, etc.);
4. psychogenic.

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Anaphylactic shock

This is a life-threatening condition that develops with an allergic reaction of the body to drugs (usually antibiotics, serums, radiocontrast agents) and food products. In most cases, it develops immediately, but can also occur after 30-40 minutes.

The main symptoms that characterize shock are: a feeling of tightness in the chest, suffocation, weakness, headache and dizziness, a feeling of heat, weakness. The development of Quincke's edema with respiratory depression, rapid depression of cardiac activity with hypotension and tachycardia, depression of consciousness up to coma are characteristic. Death can occur within a few minutes.

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Hemorrhagic shock

The development of hemorrhagic shock depends on the amount and speed of blood loss. Hemorrhagic shock develops with blood loss of over 30% of the BCC and causes an inevitable form with blood loss of over 60% of the BCC, but this is with slow blood loss and its rapid recovery.

With rapid blood loss within 15-20 minutes, even 30% of the BCC and a slowdown in its replenishment within an hour cause irreversible changes in the body. In this regard, clinicians offer an approximate indexation of shock reversibility by skin color: gray type (due to erythrocyte stasis in the capillaries) - reversible shock; white type.

Irreversible shock. Like most other forms of shock, hemorrhagic shock develops in two stages. The erectile stage is very short, literally a few minutes. It is accompanied by the patient's agitation, inadequate behavior, and in most cases, aggression. Blood pressure is slightly elevated.

The torpid phase of shock is accompanied by depression of the large, its indifference. Depending on the state of hemodynamics and the severity of hypovolemia, 4 degrees of hemorrhagic shock are conventionally distinguished: I degree - BP decreased to 100-90 mm Hg, tachycardia to 100-110 per minute; II degree - BP decreases to 80-70 mm Hg, tachycardia increases to 120 per minute; III degree - BP below 70 mm Hg, tachycardia up to 140 per minute; IV degree - BP below 60 mm Hg, tachycardia up to 160 per minute. Hypovolemic shock proceeds in the same way.

Cardiogenic shock

One of the most formidable complications of myocardial infarction, characterized by disorganization of hemodynamics, its nervous and humoral regulation and disruption of the body's vital functions.

According to pathogenesis, there are 4 forms of shock:

1. reflex shock, which is based on pain stimulation (the mildest);
2. "true" shock caused by a violation of the contractile function of the myocardium;
3. areactive shock caused by multiple factors (irreversible);
4. arrhythmic shock caused by atrioventricular block with the development of tachy- or bradystolic forms of arrhythmia.

Pain syndrome may be expressed sharply, weakly or not at all, especially in case of repeated infarctions. Peripheral manifestations: paleness of the skin, often with an ash-gray or cyanotic tint, cyanosis of the extremities, cold sweat, collapsed veins, small and frequent pulse, cyanosis of the mucous membranes - depend on the severity of the shock. Marbled pattern of the skin with pale inclusions against the background of cyanosis is an extremely unfavorable prognostic factor. There may be gastro-cardiac syndrome.

The main objective criteria for the presence and severity of cardiogenic shock are: a decrease in blood pressure below 90 mm Hg (in hypertensive patients with very high blood pressure, shock may occur with relatively normal figures, but the drop in blood pressure compared to the initial level is always pronounced); arrhythmia - tachystolic (up to atrial) or bradystolic forms; oliguria; dysfunction of the central and peripheral nervous system (psychomotor agitation or adynamia, confusion without severe inhibition or temporary loss of consciousness, changes in reflexes and sensitivity).

There are 3 degrees of shock depending on severity:

• 1st degree. Blood pressure level - 85/50 - 60/40 mm Hg. Duration 3-5 hours. Pressor reaction lasts for an hour. Peripheral manifestations are moderate.
• 2nd degree. Blood pressure level - 80/50 - 40/20 mm Hg. Duration 5-10 hours. Pressor reaction is slow and unstable. Peripheral manifestations are pronounced; alveolar pulmonary edema is observed in 20%.
• Stage 3. Blood pressure level is 60/50 and below. Duration is 24-72 hours, or heart failure progresses with the development of alveolar pulmonary edema. Pressor reaction is not expressed in most cases.

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Traumatic shock

This is a phased compensatory-adaptive response of the body to aggressive, mainly painful impact of factors, the external environment, accompanied by dysfunctional, energetic, regulatory disorders of the homeostasis system and neurohumoral reactivity of the body with the development of hypovolemia. A characteristic feature is the phased nature of the course and characteristic changes in hemodynamics, determining the severity of shock.

The phase of shock is determined by the following provisions. The brain of each individual person can perceive only a certain number of painful stimuli, which is called the "shock threshold", it can be low and high. The lower the shock threshold, the greater the probability of shock development and the severity of the developing hemodynamic changes, i.e. the degree of shock. During the period of accumulation of painful stimuli to the shock threshold, the erectile (excitation) phase of shock develops, which is accompanied by inadequate behavior of the victim, he is excited. Behavior, as a rule, depends on the situation preceding the injury. The victim can be friendly, but can also be aggressive, there is motor excitement, and the patient can even move on the injured limb. The skin is pale, there is a feverish blush on the face, the eyes are shiny, the pupils are wide. Blood pressure in this phase is not reduced, it can be increased, there is moderate tachycardia.

After reaching the shock threshold, a torpid (inhibition) phase of shock develops, which is accompanied by gradual depression of consciousness, development of hypovolemia and cardiovascular failure due to blood and plasma loss. It is by the hypovolemic syndrome and cardiovascular failure (very conditionally, since the adaptation state of the victim is specific in each specific case) that the severity of traumatic shock is judged according to the Keith classification. The severity of shock is determined only in the torpid phase.

• 1st degree (mild shock). The general condition of the victim does not inspire fear for his life. Consciousness is preserved, but the patient is inactive and indifferent. The skin is pale, the body temperature is slightly lowered. The reaction of the pupils is preserved. The pulse is rhythmic; normal filling and tension, accelerated to 100 per minute. Blood pressure is at the level of 100/60 mm Hg. Breathing is accelerated to 24 per minute, there is no dyspnea. Reflexes are preserved. Diuresis is normal, over 60 ml per hour.
• 2nd degree (moderate shock). Consciousness is soporous. Skin is pale, with a grayish tint, cold and dry. Pupils react weakly to light, reflexes are reduced. Blood pressure is 80/50 mm Hg. Pulse up to 120 per minute. Respiration is increased to 28-30 per minute with dyspnea, weakened by auscultation. Diuresis is reduced, but maintained at 30 ml per minute.
• 3rd degree (severe shock). Accompanied by deep depression of consciousness in the form of stupor or coma. The skin is pale, with an earthy tint. There is no pupillary reaction, a sharp decrease in reflexes or areflexia is noted peripherally. Blood pressure is reduced to 70/30 mm Hg. The pulse is threadlike. There is acute respiratory failure, or it is absent, which in both cases requires artificial ventilation of the lungs (ALV). Diuresis is either sharply reduced, or anuria develops.

D. M. Sherman (1972) proposed to introduce the IV degree of shock (terminal; synonyms: extreme, irreversible), which essentially represents a state of clinical death. But resuscitation measures are absolutely ineffective in this case.

There are many additional criteria for determining the severity of shock based on laboratory and instrumental studies (the Allgever principle - the ratio of pulse to BP; determination of the circulating blood volume; the lactate/pyruvate system of the creatinine index; the use of calculation formulas for shock indices, etc.), but they are not always available and do not have sufficient accuracy. We believe that Keith's clinical classification is the most accessible, accurate and acceptable.

Burn shock

It is the initial stage of burn disease. The erectile phase of burn shock is characterized by general agitation, increased blood pressure, increased respiration and pulse rate. It usually lasts 2-6 hours. After which the torpid phase of shock begins. Timely and high-quality assistance to the victim can prevent the "development of the torpid phase of shock. Conversely, additional trauma to the victim, late and unskilled assistance contribute to the severity of shock. Unlike traumatic shock, burn shock is characterized by prolonged maintenance of elevated blood pressure, which is explained by massive plasma loss in edema and pronounced vascular tone and painful irritations. A decrease in blood pressure during shock is an extremely unfavorable prognostic sign.

According to severity, in the torpid phase, there are 3 degrees of shock.

• I degree. Mild shock. Develops with superficial burns of no more than 20% and with deep burns of no more than 10%. The victims are usually calm, less often excited or euphoric. The following are noted: chills, pallor, thirst, goose bumps, muscle tremors, occasional nausea and vomiting. Breathing is not rapid. Pulse within 100-110 per minute. Blood pressure is within normal limits. Central venous pressure is normal. Renal function is moderately reduced, hourly diuresis is over 30 ml/hour. Blood thickening is insignificant: hemoglobin is increased to 150 g/l, erythrocytes - up to 5 million in 1 μl of blood, hematocrit - up to 45-55%. BCC is reduced by 10% of the norm.
• II degree. Severe shock. Develops with burns covering an area of more than 20% of the body surface. The condition is severe, the victims are agitated or inhibited. Symptoms include chills, thirst, nausea and vomiting. The skin is pale, dry, cold to the touch. Breathing is rapid. Pulse is 120-130 per minute. Blood pressure is reduced to 110-100 mm Hg. The BCC is reduced by 10-30%. There is obvious thickening of the blood: hemoglobin increases to 160-220 g / l, erythrocytes - up to 5.5-6.5 million in μl of blood, hematocrit - up to 55-65%. Renal failure is formed, hourly diuresis is less than 10 ml / hour, hematuria and proteinemia are common, the specific gravity of urine is significantly increased; Blood slags increase: residual nitrogen, creatinine, urea. Due to microcirculation disorders, tissue metabolism decreases with the development of acidosis and water-electrolyte changes in the blood: hyperkalemia and hyponatremia.
• III degree. Extremely severe shock. Develops when over 60% of the body surface is damaged by superficial burns or 40% by deep burns. The condition is extremely severe, consciousness is confused. There is a painful thirst, often uncontrollable vomiting. The skin is pale, with a marbled tint, dry, its temperature is significantly reduced. Breathing is rapid, with severe dyspnea. Blood pressure is below 100 mm Hg. Pulse is threadlike. BCC is reduced by 20-40%, which causes circulatory disorders in all organs and tissues. Blood thickening is sharp: hemoglobin increases to 200-240 g / l, erythrocytes to 6.5-7.5 million per μl of blood, hematocrit - up to 60-70%. Urine is completely absent (anuria), or there is very little of it (oliguria). Blood toxins increase. Liver failure develops with an increase in bilirubin and a drop in the prothrombin index.

The duration of the torpid phase of shock is from 3 to 72 hours. With a favorable outcome, which is determined by the severity of the burn and shock, the timeliness of assistance, the correctness of the treatment, peripheral blood circulation and microcirculation begin to recover, body temperature increases, and diuresis normalizes.

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