In medical terminology, the concept of "shock" refers to a critical level of microcirculation in the human body, at which the vascular capacity as a whole does not correspond to the amount of circulating blood.
Among the reasons for this condition may be an acute loss of blood - its instantaneous sudden exit beyond the limits of the vessel bed. A similar shock, which appears due to pathological acute blood loss of more than 1-1.5% of body weight, is called hemorrhagic or hypovolemic.
Multiple organ failure and reduced blood supply to the organs that accompany this condition manifest clinically as tachycardia, low blood pressure, and pallor of the mucous membranes and epidermis.
Reasons
The causes of hemorrhagic shock in acute loss are divided into three main bleeding groups:
- post-traumatic;
- spontaneous;
- postoperative.
Often named condition occurs in obstetrics, acting as one of the main causes of death of a woman. As a rule, they lead to it:
- placenta previa or premature abruption;
- bleeding after childbirth;
- uterine atony and hypotension;
- obstetric injuries of the genital tract and uterus;
- ectopic pregnancy;
- fetal death inside the womb;
- vascular amniotic fluid embolism.
Additional factors
In addition, hemorrhagic shock can be caused by oncological diseases and sepsis processes, which provoke extensive tissue necrosis and erosion of the vascular wall.
Of no small importance in the appearance of the described pathology is the rate of blood loss. If the bleeding is slow, then compensatory mechanisms are activated, and therefore hemodynamic disturbances appear gradually and do not lead to significant consequences. And with a rapid loss of blood (even if its volume is less), this leads to serious hemodynamic defects that end in hemorrhagic shock.
Symptoms
For diagnosing hemorrhagic shock based on an assessment of the main clinical signs:
- on the patient's state of mind;
- color of visible skin and mucous membranes;
- breath rate;
- value and condition of the pulse;
- venous and systolic pressure levels;
- the amount of diuresis, that is, the amount of urine excreted.
Despite the significance of the assessmentindicators, it is extremely short-sighted and dangerous to rely only on the subjective feelings of the patient. Clinically significant signs appear mainly already in the uncompensated, second stage of hemorrhagic shock in obstetrics, and the most significant among them is a systematic decrease in blood pressure, which indicates the depletion of the patient's compensatory mechanisms.
Determining the degree of blood loss
In order to effectively and adequately carry out therapy for hemorrhagic shock, it is very important to establish the degree of blood loss in a timely and accurate manner. Among the classifications that currently exist, the following one has received the greatest use in practice:
- Mild degree (blood loss from 10 to 20% of blood volume), which does not exceed one liter.
- Medium degree (blood loss from 20 to 30%) - up to one and a half liters.
- Severe degree (about forty percent blood loss), reaching two liters.
- Massive or extremely severe blood loss - more than 40% of blood volume is lost, that is, more than two liters.
In some cases, with intense blood loss, irreversible defects in homeostasis develop, which are not corrected even by an instant replenishment of blood volume.
Varieties of blood loss
How is bleeding in hemorrhagic shock classified? Doctors believe that the following types of blood loss are capable of being fatal:
- Loss throughout the day100% of her total.
- Loss over 3 hours 50%.
- Instant loss of 25%.
- Forced blood loss up to 150 ml per minute.
Assessing
To establish the severity of hemorrhagic shock and blood loss, a comprehensive assessment of hemodynamic, paraclinical and clinical parameters is used. Of great importance is the calculation of the Algover shock index, which is defined as a quotient as a result of dividing the heart rate by the systolic pressure.
The shock index is normally less than one. Depending on the severity of shock and the level of blood loss, this can be an index in the range:
- 1-1, 1 - corresponds to a mild degree;
- 1, 5 – medium degree;
- 2 - heavy;
- 2, 5 - extremely severe.
In addition to the Algover index, you can calculate the volume of lost blood by measuring central venous and arterial pressure, monitoring hourly and minute diuresis, hemoglobin content in the blood, and also finding out the proportion with the hematocrit value, that is, the specific mass of red blood cells in the total blood volume.
Mild blood loss is indicated by the following symptoms:
- Heart rate below 100 beats for a minute.
- Dryness, pallor and low temperature of the skin.
- The value of hematocrit is within 38-32%.
- Central venous pressure - three to six millimeterswater column, urine output over thirty milliliters.
Medium blood loss is even more pronounced:
- Increased heart rate up to 120 beats per minute.
- Anxiety and agitation, the appearance of a sick patient in a cold sweat.
- Decrease in CVP to three to four centimeters of water column.
- Decrease in hematocrit within 22-30%.
- Urine output below thirty milliliters.
Severe blood loss is characterized as follows:
- Tachycardia over 120 beats per minute.
- Lower blood pressure less than 70 mm Hg, venous pressure less than 3 mm H2O.
- Manifesting skin pallor, which is accompanied by sticky sweat, lack of urine (anuria).
- Hematocrit less than 22% and hemoglobin less than 70 grams per liter.
Let's consider the stages of hemorrhagic shock in obstetrics.
Degrees of severity
The degree of manifestation of the clinical picture of this condition is determined by the amount of blood loss and is distributed depending on this as follows:
- first (easy);
- second (middle);
- third (heavy);
- fourth (extremely difficult).
In a patient with first degree hemorrhagic shock, blood loss is no more than 15% of the volume as a whole. At this stage, patients are contact, their consciousness is preserved. Paleness of mucous membranes and skinaccompanied by a more frequent pulse (reaches 100 beats), low arterial hypotension and oliguria, that is, a decrease in the amount of urine produced.
Signs of shock of the second degree are, in addition to those listed, high sweating, anxiety, acrocyanosis, that is, cyanosis of the fingers and lips. There is an increase in the pulse to 120 beats, breathing has a frequency of up to 20 per minute, blood pressure decreases, oliguria increases. The shortage of CC increases to 30%.
In the third degree of hemorrhagic shock, blood loss reaches forty percent. Patients are confused, marbling and pallor of the skin are strongly pronounced, the pulse rate is more than 130. In patients in this condition, oliguria and shortness of breath (up to thirty breaths per minute) are observed, arterial systolic pressure is less than 60 millimeters of mercury.
The fourth stage of hemorrhagic shock is characterized by a lack of CK over 40%, as well as suppression of life-important functions: there is no consciousness, pulse and venous pressure. In addition, patients have shallow breathing, anuria, and areflexia.
Mechanisms affecting shock severity
Pathological processes in the development of hemorrhagic shock in humans are based on a sudden decrease in the volume of blood that circulates through the vessels. A decrease in the portions of blood ejected by the heart reflexively causes vascular spasm in various organs, including those important for life, such as the brain, lungs and heart.
Blood thinning (hemodilution),which occurs due to the transition of fluid into the vessel from the tissues, changes the rheological blood properties (erythrocyte aggregation) and causes a steady spasm of arterioles, causing irreversible defects in microcirculation in organs and tissues.
Catastrophic changes in microcirculatory processes that occur after a crisis of macrocirculation are irreversible, life-threatening for the patient.
Emergency care for hemorrhagic shock
The main goal of emergency procedures is to find the source of blood loss and eliminate it, which often requires surgical intervention. To stop bleeding for a while, use a bandage, tourniquet or endoscopic hemostasis. The next step, which eliminates shock and saves the patient's life, is the immediate replenishment of the amount of circulating blood.
Help for hemorrhagic shock should be immediate.
Infusion rate
The rate of intravenous infusion of solutions should be at least 20% higher than the rate of blood loss. To determine it, indicators such as heart rate, CVP and blood pressure are used. Urgent measures also include catheterization of large vessels, which provides reliable access to the bloodstream and the required speed of effects.
In the terminal stage, infusions into the artery are used. Important emergency measures are also: mechanical ventilation, inhalation of oxygen using a mask, patient care (warming),proper anesthesia.
Hemorrhagic shock treatment
After stopping bleeding and venous catheterization, intensive treatment has the following goals:
- Elimination of hypovolemia, as well as replenishment of the amount of CK.
- Ensuring correct cardiac output and microcirculation.
- Detoxification.
- Restoration of the previous indicators of oxygen-transporting blood capacity and osmolarity.
- Prevention of red blood cell aggregation (DIC).
- Rebalancing and maintaining diuresis.
To reach them, the advantage in infusion treatment is given:
- HES solutions (up to one and a half liters per day) and normalization of oncotic blood pressure;
- crystalloid intravenous solutions up to two liters until blood pressure returns to normal;
- colloidal solutions (dextrans and gelatins) in a ratio of 1:1 to the infusion volume as a whole;
- erythrocyte mask and other blood substitutes with the observation of CVP to the degree of hematocrit within 32-30%;
- use of donor blood;
- maximum doses of glucocorticosteroids.
trental.
Recommendations for hemorrhagic shock shouldbe strictly observed.
Complications
In the decompensated form of shock, reperfusion syndrome, DIC, asystole, coma, myocardial ischemia, ventricular fibrillation may occur. After a few years, endocrine diseases and chronic pathologies of internal organs can develop, leading to disability.
