In medical terminology, the term “shock” refers to the 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 causes of this condition may be an acute loss of blood - its instantaneous sudden exit beyond the boundaries of the bloodstream of the vessel. Such a shock that occurs due to pathological acute blood loss of more than 1-1.5% of body weight is called hemorrhagic or hypovolemic.
Multiple organ failure and a decrease in the blood supply to organs that accompany this condition are clinically manifested in the form of tachycardia, lowering blood pressure, as well as pallor of the mucous membranes and epidermal cover.
Causes
The causes of hemorrhagic shock in acute loss are divided into three main groups of bleeding:
- post-traumatic;
- spontaneous;
- postoperative.
Often named condition happens in obstetrics, speaking as one of the main causes of death of a woman. As a rule, they lead to it:
- placenta previa or its premature detachment;
- bleeding after childbirth;
- uterine atony and hypotension;
- obstetric injuries of the genital tract and uterus;
- ectopic pregnancy;
- fetal death inside the womb;
- vascular embolism of amniotic fluid.
Additional factors
In addition, oncological diseases and sepsis processes that provoke extensive tissue necrosis and erosion of the vascular wall can cause hemorrhagic shock.
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 connected, and therefore hemodynamic disturbances appear gradually and do not lead to significant consequences. And with rapid loss of blood (even if its volume is less), this leads to serious hemodynamic defects that result in hemorrhagic shock.
Symptoms
To diagnose hemorrhagic shock, they are based on an assessment of the main clinical signs:
- on the state of consciousness of the patient;
- the color of the visible integuments of the skin and mucous membranes;
- respiratory rate;
- the size and condition of the pulse;
- level of venous and systolic pressure;
- the amount of urine output, that is, the amount of urine excreted.
Despite the significance of the evaluation of indicators, it is extremely short-sighted and dangerous to rely only on the subjective sensations 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 compensation mechanisms of the patient's body.
Determining the degree of blood loss
In order to effectively and adequately conduct 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 largest application in practice has received this:
- Mild degree (blood loss from 10 to 20% of the blood volume), which does not exceed one liter.
- The average degree (blood loss from 20 to 30%) - up to one and a half liters.
- Severe degree (blood loss of about forty percent), reaching two liters.
- Massive or extremely severe blood loss - more than 40% of the blood volume is lost, that is, more than two liters.
In some cases, with intense loss of blood, irreversible defects of homeostasis develop, which are not corrected even by instant replenishment of the blood volume.
Varieties of blood loss
How are bleeding classified in hemorrhagic shock? Doctors believe that the following types of blood loss can lead to death:
- Loss during the day 100% of its total.
- Loss for three hours 50%.
- Instant loss of 25%.
- Forced blood loss at a rate of up to 150 ml per minute.
Assessment
To establish the severity of hemorrhagic shock and blood loss, a comprehensive assessment of hemodynamic, paraclinical and clinical indicators is used. Of great importance is the calculation of the Algover shock index, which is defined as the quotient as a result of dividing the heart rate by the rate of systolic pressure.
The shock index is normally less than one. Depending on the severity of the shock and the level of blood loss, this may be an index within:
- 1-1.1 - corresponds to a mild degree;
- 1.5 - average degree;
- 2 - heavy;
- 2.5 - extremely difficult.
In addition to the Algover index, the volume of blood lost can be calculated by measuring central venous and arterial pressure, monitoring hourly and minute diuresis, the hemoglobin content in the blood, and also determining the proportion with the hematocrit value, i.e. the specific weight of red blood cells in the total blood volume.
The following symptoms indicate a mild degree of blood loss:
- Heart rate below one hundred beats per minute.
- Dryness, pallor and lowered skin temperature.
- The hematocrit value is in the range of 38-32%.
- The central pressure in the vein is from three to six millimeters of water, the urine output is over thirty milliliters.
The average degree of blood loss is manifested by even more pronounced signs:
- Increased heart rate up to 120 beats per minute.
- Anxiety and agitation, the appearance of a cold sweat in a sick patient.
- Reducing the CVP to three to four centimeters of water.
- Hematocrit reduction in the range of 22-30%.
- Diuresis below thirty milliliters.
Severe degree of blood loss is characterized as follows:
- Tachycardia over 120 beats per minute.
- Lowering blood pressure less than 70 millimeters of mercury, venous - below three millimeters of water.
- The manifesting skin pallor, which is accompanied by a sticky sweat, lack of urine (anuria).
- A decrease in hematocrit is less than 22%, and hemoglobin is below 70 grams per liter.
Consider the stages of hemorrhagic shock in obstetrics.
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 (light);
- second (middle);
- third (heavy);
- fourth (extremely difficult).
In a patient having a first degree of hemorrhagic shock, blood loss is not more than 15% of the total volume. At this stage, patients are in contact, their consciousness is preserved. The pallor of the mucous membranes and skin is accompanied by a more frequent pulse (reaches 100 strokes), low arterial hypotension and oliguria, that is, a decrease in the amount of urine produced.
Signs of a second degree shock are, in addition to the above, high sweating, anxiety, acrocyanosis, that is, cyanosis of the fingers and lips. There is an increase in heart rate up to 120 beats, breathing has a frequency of up to 20 within a minute, blood pressure decreases, oliguria rises. The lack of quantity of CK increases to 30%.
With a third degree of hemorrhagic shock, blood loss reaches forty percent. Patients are confused, marbling and pallor of the skin are very pronounced, pulse rate is more than 130. Patients in this condition have oliguria and shortness of breath (up to thirty respiratory movements per minute), arterial systolic pressure has a rate of less than 60 millimeters of mercury.
The fourth stage of hemorrhagic shock is characterized by a deficiency in the amount of CK over 40%, as well as the suppression of vital functions: there is no consciousness, pulse, and venous pressure. In addition, patients experience shallow breathing, anuria, and areflexia.
Mechanisms affecting the severity of shock
Pathological processes in the development of hemorrhagic shock in a person are based on a sudden decrease in the volume of blood that circulates through the vessels. Reducing 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 passage of fluid into the bloodstream of the tissue, introduces changes in the rheological blood properties (erythrocyte adhesion) and causes a persistent spasm of arterioles, which causes irreversible microcirculation defects in organs and tissues.
The catastrophic changes in microcirculatory processes that occur after a macrocirculation crisis are irreversible, dangerous to the patient's life.
Emergency care for hemorrhagic shock
The main goal of emergency manipulations is to find the source of blood loss and its elimination, and therefore often requires surgical intervention. To stop bleeding for a while, use a bandage, tourniquet or endoscopic hemostasis. The next step, eliminating shock and saving the patient's life, is the immediate replenishment of the amount of circulating blood.
Help with hemorrhagic shock should be immediate.
Infusion rate
The infusion rate inside the vein of the solutions should be at least 20% higher than the rate of blood loss. To determine it, apply indicators such as heart rate, CVP and blood pressure. Catheterization of large vessels, which provides reliable access to the bloodstream and the required speed of the effects produced, also belong to urgent measures.
At the terminal stage, infusions into the artery are used. Important emergency measures are also: artificial pulmonary ventilation, inhalation of oxygen using a mask, patient care (warming), proper pain relief.
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 proper cardiac output and microcirculation.
- Detoxification.
- Restoring former oxygen transport blood capacity and osmolarity.
- Prevention of red blood cell aggregation (DIC).
- Bringing back and maintaining diuresis.
To achieve them, the advantage in infusion treatment is given:
- HES solutions (per day up to one and a half liters) and normalization of oncotic blood pressure;
- crystalloid intravenous solutions in an amount of up to two liters, until blood pressure normalizes;
- 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%;
- donor blood use;
- maximum doses of glucocorticosteroids.
Of great importance in the treatment are drugs that dilate blood vessels and are necessary for the elimination of vascular spasm (Eufillin, Papaverine), the prevention of reperfusion syndrome, for which alkalizing solutions, GHB, antihistamines, antioxidants, proteolysis inhibitors and trental are used.
Recommendations for hemorrhagic shock should be strictly followed.
Complications
With a decompensated form of shock, reperfusion syndrome, DIC, asystole, coma, myocardial ischemia, ventricular fibrillation can occur. In a few years, endocrine diseases and chronic pathologies of the internal organs can develop, leading to disability.