From this article you will learn: what is hypovolemic shock, under what diseases it develops and how it manifests itself. Principles of diagnosis, first aid and treatment in this condition.
Causes of hypovolemic shock
Hypovolemic shock is a life-threatening condition in which rapid loss of body fluid leads to severe disruption of manydue to their inadequate blood supply.
Loss of fluid leads to a decrease in the volume of circulating blood, a drop in blood pressure and a deterioration in the perfusion( blood supply) of all organs. To a patient with hypovolemic shock survived, he needs immediate medical attention. If blood supply of vital organs is not improved in the shortest possible time, irreversible changes in tissues appear and the patient dies.
What happens with hypovolemic shock Given the timely and correct treatment in most patients, it is possible to quickly enough improve the blood supply of all organs. The prognosis in patients depends on the causes of the development of the condition.
All patients with shock need treatment in the intensive care unit( resuscitation), so their treatment is performed by anaesthesiologists.
Causes of hypovolemic shock
Hypovolemia is a decrease in the volume of circulating blood. It can develop as a result of a significant and rapid loss of blood or fluid by the body. If the cause of hypovolemic shock is blood loss, it is called hemorrhagic.
Table 1. Possible causes of hemorrhagic shock:
| Bleeding type | Causes of |
|---|---|
| External bleeding | Traumatic injury Bleeding from the uterus( metrorrhagia) |
| Gastrointestinal bleeding | Varicose esophageal varices ruptured( developed in patients with cirrhosis) Mucosal ruptureesophagus due to severe vomiting( Mellory-Weiss syndrome) Aorto-intestinal fistula( canal connecting the aorta with the lumen of the intestine) Bleeding from the stomach ulcer orvenadtsatiperstnoy intestine intestinal bleeding in ulcerative colitis or diverticulitis bleeding from a tumor of the stomach or intestines |
| Internal bleeding | Rupture of the spleen due to injury rupture of an aortic aneurysm dissecting aortic aneurysm pelvic fracture or femoral blood loss during or after surgery |
| bleeding relatedwith pregnancy | Ectopic pregnancy Placenta previa Placental abruption Uterine rupture Afterbirth bleeding |
Blood carries oxygen and other essential substances to organs and tissues. With the development of severe bleeding in the cardiovascular system of the blood becomes insufficient, which leads to violations of the functioning of the organs and the development of hemorrhagic shock.
Another cause of hypovolemic shock is loss of body fluid, which leads to a decrease in the volume of circulating blood due to a decrease in the amount of plasma.
Table 2. Possible causes of large body fluid loss:
| Bleeding type | Causes of |
|---|---|
| Loss of blood plasma | Severe burns affecting> 15% of skin surface |
| Water loss | Incontinent vomiting Severe diarrhea( due to cholera, rotavirus infection in children) Polyuria( large amount of urine) caused by diabetes mellitus,ingestion of diuretics |
| Endocrine causes | Severe, acute hyperthyroidism with fever and diarrhea Acute adrenal insufficiency with polyuria, vomiting and diarrhea |
Symptoms of hypovolemic
hypovolemic shock shock can manifest different symptoms, depending on the severity of blood or fluid loss. However, shock of any severity is life-threatening and needs immediate treatment.
One of the main criteria available for people without medical education, with which you can suspect the presence of shock, is a reduction in systolic blood pressure below 90 mm Hg. Art.
The determination of the degree of blood loss is carried out using the Algover index . The clinical picture develops when 10-20% of the circulating blood volume in adults or 30% in children is lost. Early symptoms and signs:
- Thirst.
- Nausea.
- Anxiety, irritability, insomnia, confusion.
- Pale skin, covered with sticky sweat.
- Symptoms of bleeding - vomiting of blood, blood in the stool, pain in the chest, back or stomach( exfoliating aortic aneurysm), bleeding from the external genitalia in women.
- Symptoms of loss of body fluids - vomiting, diarrhea, severe burns.
- Extended pupils.
- Rapid heart rate( tachycardia).
- Reduced blood pressure.
- Rapid breathing.
- Signs of dehydration in children - a bad skin turgor, sunken fontanel in infants, weight loss.
Locations of the aortic aneurysm: A - norm;B - thoracic aortic aneurysm;C - abdominal aortic aneurysm If a patient with these symptoms does not receive immediate and adequate medical care, his condition worsens. Developed late signs and symptoms of hypovolemic shock:
- dizziness;
- syncope;
- general weakness and fatigue;
- confusion;
- lethargy( severe drowsiness);
- marked tachycardia;
- strongly rapid( above 30 times per minute) or slow( less than 12 times per minute) breathing;
- decrease in body temperature;
- sharp decrease in blood pressure;
- decrease in the amount of urine or complete absence of urine;
- coma.
Diagnosis
The easiest way to diagnose hypovolemic shock is by examining the doctor, during which a drop in blood pressure, increased heart rate and breathing, low body temperature and other signs of shock are detected.
After the examination, the doctor can prescribe the following laboratory and instrumental examinations based on information on the hypovolaemia suspected cause:
- A general blood test with determination of hemoglobin, erythrocytes and hematocrit.
- Biochemical blood test with determination of sodium, potassium, chlorine, urea, creatinine and glucose levels.
- General analysis of urine.
- Blood coagulation test.
- Computer or magnetic resonance imaging, ultrasound and X-ray examination of the area with a possible source of blood loss.
- Endoscopic examination of the digestive tract( with suspicion of gastrointestinal bleeding).
- Pregnancy test in women of childbearing age.
All these examinations are not performed for each patient. Sometimes the cause of hypovolemic shock is visible to the naked eye - for example, external bleeding after the resulting injury with damage to the blood vessels.
Stages and degrees of hypovolemic shock
There are many classifications of hypovolemic shock, the main ones of which are designed to establish the stage and extent of hemorrhagic shock.
Table 3. Degrees of hemorrhagic shock
| Degree | Acute loss | Description |
|---|---|---|
| 1 degree | & lt;15% | Blood loss of this size rarely causes a marked clinical picture. Blood pressure and respiration are usually normal. The most noticeable symptom is the pallor of the skin. Sometimes the patient may experience anxiety. |
| 2 degree | 15-30% | Patients may develop heart palpitations and breathing. Their blood pressure can still remain within normal limits, decreasing only when passing from a lying position to a standing position( orthostatic hypotension).Moreover, diastolic blood pressure can be even slightly increased. The patient may begin to sweat and become restless. |
| 3 degree | 30-40% | Systolic blood pressure drops to 100 mm Hg. Art.and below. Patients also have a marked increase in heart rate and respiratory rate. They may have expressed anxiety and excitement. The skin becomes pale and cold. |
| 4 degree | & gt;40% | The pulse becomes weak, but very frequent. It becomes very difficult for the patient to breathe. Systolic BP falls below 70 mm Hg. Art. With this degree of blood loss, patients may lose clear consciousness, their speech becomes incoherent and incomprehensible in such cases. Skin pale, cold and covered with sweat. |
The following stages of shock are distinguished:
- Compensated shock receptors in the vessels lead to increased heart rate, increased frequency and narrowing of the vessels. These changes in the cardiovascular system maintain blood pressure at a normal level and lead to the release of hormones of vasopressin, aldosterone and renin, which delay sodium and fluid in the body.
- Progressive or decompensated shock - deterioration of heart contractility, weakened vasoconstriction, there is a violation of microcirculation with increased permeability of the capillaries and their thrombosis. These changes lead to a pronounced disruption in the blood supply of tissues and the death of their cells.
- Irreversible shock - there is a multi-organ failure, which can not be eliminated.
Treatment of hypovolemic shock
Hypovolemic shock, if untreated, ultimately leads to patient death. Therefore, you need to immediately call an ambulance in case of development of signs of this condition in any person. Before ambulance:
- Place the patient on his back with his legs raised about 30 cm.
- Do not move the patient if he could have a head, neck or back injury.
- Try to warm the patient to avoid hypothermia.
First aid for external bleeding:
- Wear rubber gloves, if any.
- If it is unlikely that the victim has a spinal cord injury( he has a sensitivity in his hands and feet), put it and raise the bleeding part of the body 30 cm above the level of the heart, if possible.
- Check the wound and remove free-lying foreign objects( eg sand, cloth) from it. Never remove objects that are stuck in the wound( for example, a knife or a sharp branch).
- If possible, remove the edges of the wound together and fix them in this position with a bandage.
- To stop bleeding, cover the wound with gauze and apply pressure on it for 20 minutes. During this time, do not check if bleeding has stopped. If there is no gauze at hand, use a piece of any cloth or a clean plastic bag. If the cloth or gauze is soaked with blood, you can not remove it from the wound, you need to add one more layer.
- In case of arterial bleeding( discharge of bright red blood by a pulsating jet), place an improvised tourniquet above the injury from the arm or leg and tighten it strongly. The harness can be made from a durable fabric or belt.
- If the victim becomes cold, cover him with a blanket.
- Do not give the patient anything to drink or eat, even if he is thirsty.
Method of superposition of arterial plait with improvised means First aid for suspected internal bleeding
Internal bleeding may be invisible. Its existence can be suspected in people affected by accidents, from falls from a height. First aid:
- If the victim most likely does not have a spinal cord injury, put it and lift the body feet 30 cm above the heart.
- Do not give the patient anything to drink or eat, even if he is thirsty.
Medical treatment of hypovolemic shock
The goals of treatment of any kind of hypovolemic shock are to restore the volume of blood circulation and improve the blood supply of organs. However, the methods for achieving these goals can vary greatly depending on the causes of the development of shock.
With hemorrhagic shock, it is necessary to first stop bleeding with conservative( with the help of medicines) or by surgical methods, and only then try to restore the volume of circulating blood and increase blood pressure. The fact is that if you try to normalize the pressure with continued intravenous fluid during continued bleeding, this leads to increased blood loss.
In a hospital with a hypovolemic shock, intravenously injected solutions or blood products( erythrocytes, plasma, platelets), replenishing blood loss and improving blood supply to organs.
For a rapid replenishment of the circulating blood volume, physiological saline is used. If there is a need for rapid increase in arterial pressure, doctors prescribe medications that enhance cardiac contractions and narrow blood vessels. Most commonly used:
- noradrenaline;
- dopamine;
- adrenaline;
- mezaton.
All further methods of treatment of hypovolemic shock depend on the cause of its development.
Forecast
Hypovolemic shock is not an independent pathology, but a symptom of the underlying disease. Provided that emergency care is provided and the correct treatment is carried out in a timely manner, the prognosis does not depend on the shock itself, but on the kind of disease that led to its development.
Otherwise, the forecast depends on:
- Stages of shock.
- The magnitude of blood loss.
- The existence of other diseases, such as heart disease or diabetes.
