It is a state of decreased blood volume; more specifically, decreased volume of blood plasma.
Hypovolemic shock, also known as hemorrhagic shock, is a life-threatening condition that occurs when you lose more than 20 percent (one-fifth) of your body’s blood or fluid supply.
This severe fluid loss makes it impossible for the heart to pump enough blood to your body. Hypovolemic shock can lead to organ failure.
It is, therefore, the intravascular component of volume contraction (or loss of blood volume due to things like bleeding or dehydration), but, as it is also the most essential, hypovolemia and volume contraction are sometimes used as synonyms.
Hypovolemia is characterized by sodium depletion (salt depletion) and therefore differs from dehydration, which is defined as excessive loss of body water.
Hemorrhagic shock occurs when the body begins to shut down due to large amounts of blood loss. People who sustain injuries that involve heavy bleeding may experience hemorrhagic shock if the bleeding does not stop immediately.
Symptoms of hemorrhagic shock
All shock symptoms are life threatening and should be treated as a medical emergency. Symptoms of hemorrhagic shock may not appear right away.
Anxiety, blue lips and nails, little or no urine output, profuse (excessive) sweating, shallow breathing, dizziness, confusion, chest pain, loss of consciousness, low blood pressure , fast heart rate and weak pulse.
External bleeding (bleeding) will be visible. Symptoms of internal bleeding, however, can be difficult to recognize until symptoms of shock appear.
Signs of internal bleeding include:
Abdominal pain, blood in stool, blood in urine, vaginal bleeding (heavy, usually outside of normal menstruation), vomiting of blood, chest pain, and abdominal swelling.
Seek medical attention immediately if you have signs of bleeding or hemorrhagic shock. Have someone drive you to the hospital or call 911. Do not drive alone to the hospital if you are bleeding profusely or have any symptoms of shock.
Blood carries oxygen and other essential substances to your organs and tissues. When heavy bleeding occurs, these substances are lost faster than they can be replaced, and organs in the body begin to shut down.
As your heart shuts down and an adequate amount of blood stops circulating through your body, symptoms of shock occur. Blood pressure plummets and there is a massive drop in body temperature, which can be life threatening.
The obvious cause of hypovolemic shock is blood loss , but that’s not all. Blood loss can come from external or internal bleeding due to illness or injury. Most of the time, hypovolemic shock will be a complication of another condition.
Common causes of hypovolemia are:
- Loss of blood (external or internal bleeding or blood donation).
- Loss of plasma (severe burns and injuries that discharge liquid).
- Loss of body sodium and consequent intravascular water; p. ex. diarrhea or vomiting
Blood levels may also drop when the body loses other fluids. Burns, diarrhea, and vomiting can be all possible causes.
Medical professionals and first responders are trained to recognize the signs of blood loss. However, it is also helpful for people to be aware of the possibility, for themselves and others, that they can get help as quickly as possible.
Excessive sweating is not a cause of hypovolemia, because the body removes significantly more water than sodium.
Blood loss of this magnitude can occur due to bleeding from severe cuts or wounds, bleeding from blunt traumatic injuries due to accidents, internal bleeding from abdominal organs or ruptured ectopic pregnancy, bleeding from the digestive tract, and significant vaginal bleeding.
In addition to the actual blood loss, the loss of body fluids can cause a decrease in blood volume. This can occur in cases of excessive or prolonged diarrhea, severe burns, prolonged and excessive vomiting, excessive sweating.
Diagnosis of hemorrhagic shock
Clinical symptoms may not be present until 10-20% of the total total blood volume is lost.
Hypovolemia can be recognized by tachycardia, decreased blood pressure, and lack of perfusion as assessed by skin signs (skin turns pale) and / or capillary filling on the forehead, lips, and nail beds.
The patient may feel dizzy, weak, nauseous, or very thirsty. These signs are also characteristic of most types of shock.
Note that in children compensation can lead to artificially high blood pressure despite hypovolemia.
Children will generally compensate (maintain blood pressure despite the loss of blood volume) for a longer period than adults, but will deteriorate rapidly and severely once they begin to decompensate.
This is another reason (aside from the lower initial blood volume) that even the possibility of internal bleeding in children almost always needs to be treated aggressively.
Shock requires immediate attention, so treatment can begin before diagnosis. If the reason for the shock is not obvious or is internal, various tests may be used to diagnose the cause, including X-rays, blood tests, ultrasound, computed tomography (CT), magnetic resonance imaging (MRI). English).
Your doctor may order a complete blood count test after addressing the bleeding site.
These results will let them know if a blood transfusion is necessary. Your doctor may also order a blood transfusion without doing a complete blood count test if there is a large amount of blood lost from the injury.
A blood transfusion is given by transferring blood from a donor to your body using an IV. Medicines, such as dopamine, may be given to increase your blood pressure.
Obvious signs of external bleeding should be noted when remembering that people can bleed to death internally without external blood loss.
Possible mechanisms of injury that may have caused internal bleeding, such as broken or bruised internal organs, should be considered.
If trained to do so and if the situation permits, a secondary survey should be performed and the chest and abdomen examined for pain, deformity, protection, discoloration, or swelling.
Bleeding into the abdominal cavity can cause the classic Gray Turner sign or Cullen sign bruising patterns.
It is generally known as a “class” of shock. Most sources state that there are 4 stages of hypovolemic shock; however, there are a number of other systems with up to 6 stages.
The 4 stages are sometimes referred to as the “Tennis” stage of hypovolemic shock, as the stages of blood loss (less than 15% of volume, 15-30% of volume, 30-40% of volume, and more than 40% of the volume) mimic the scores in a tennis game: 15, 15-30, 30-40 and 40.
It is basically the same as that used in the classification of bleeding due to loss of blood.
To get an overview of hypovolemic shock, it is important to look at the stages of the condition as it appears:
A person with the earliest stage of hypovolemic shock will have lost up to 15 percent of their blood. This loss can be difficult to diagnose. Blood pressure and breathing will generally be normal.
The most noticeable symptom at this stage is that the skin will start to look pale. The person may also be experiencing anxiety.
In the second stage, blood loss increases by up to 30 percent. The patient may experience an increase in heart and respiration rates.
Your blood pressure may still be within the normal range. However, the diastolic reading, or the lower number of your blood pressure reading, can increase. The patient may begin to sweat and feel more anxious and restless.
In stage 3, the person with hypovolemic shock will have a 30 to 40 percent blood loss. The maximum number or systolic reading of your blood pressure will be 100 or less. They will have a significantly higher heart rate and abnormally fast breathing.
The patient will begin to experience mental problems, including anxiety and agitation. Their skin will be pale and cold, and they will start to sweat.
A person with stage 4 blood loss shock will be in real danger. They will have experienced a blood volume loss of more than 40 percent. They will have a weak pulse but a fast heart rate.
Breathing will be extremely difficult. Your blood pressure readings will be less than 70 for the top number. They can be in and out of consciousness, sweaty, cold to the touch, and extremely pale.
Risk factors for hypovolemic shock
Since this type of shock occurs due to illness or injury, it is difficult to determine risk factors. Anyone is potentially at risk of developing this condition, although it is relatively rare.
Dehydration can be a contributing factor in some cases of hypovolemic shock. Continuing to drink water is very important, especially during illnesses where vomiting or diarrhea may occur.
While a person cannot always control an injury or illness that can cause hypovolemic shock, they can try to prevent further complications by rehydrating.
The effects of hypovolemic shock depend on the rate at which you are losing blood or fluids and the amount of blood or fluids you are losing. The extent of your injuries can also determine your chances of survival.
Treatment for hypovolemic shock itself, which is usually caused by another condition, can be as complicated as diagnosing it.
The most important step in treating hypovolemic shock is identifying and controlling the source of the bleeding. Emergency oxygen should be used immediately to increase the efficiency of the patient’s remaining blood supply. This intervention can save lives.
Using intravenous (IV) fluids can help compensate for the loss of fluid volume, but IV fluids cannot carry oxygen the way blood does; however, blood substitutes are being developed that can.
Infusion of colloidal or crystalloid intravenous fluids will also dilute clotting factors within the blood, increasing the risk of bleeding .
It is current best practice to allow permissive hypotension in patients suffering from hypovolemic shock, both to ensure that clotting factors are not overly diluted and to artificially stop blood pressure to the point where it “flushes out” clots that have formed. .
Fluid replacement is beneficial in stage 2 hypovolemia, and is necessary in stages 3 and 4. See also the discussion of shock and the importance of treating reversible shock while it can still be counteracted.
For a patient presenting with hypovolemic shock in hospital, the following investigations would be carried out:
- Blood tests: U + Es / Chem7, complete blood count, glucose and blood type.
- Central venous catheter or blood pressure.
- Arterial line or arterial gasometry.
- Measurements of urine output (through the urinary catheter).
- Blood pressure.
The following interventions would be carried out:
- IV access.
- Oxygen as needed.
- Surgical repair at bleeding sites.
- Inotropic therapy (dopamine, norepinephrine) that increases the contractility of the heart muscle.
- Fresh frozen plasma or whole blood.
In general, vasopressors (such as norepinephrine, dobutamine) should be avoided as they can lead to increased tissue ischemia and not correct the main problem. Liquids are the preferred option of therapy.
Some people can also develop gangrene due to decreased circulation in the extremities. This infection can result in the amputation of the affected limbs.
Common complications of hemorrhagic shock include kidney or other organ damage and death. Your outlook will depend on the amount of blood you lost and the type of injury you sustained.
The prognosis is better in healthy people who have not had severe blood loss.
How does hypovolemic shock affect older patients?
As with many conditions, hypovolemic shock is a specific concern in older adults. Because age has an impact on the body’s circulatory system, any stress caused by blood loss and other symptoms of shock can lead to further damage.
Loss of blood at this level can also contribute to heart failure or stroke. Older patients should have access to emergency care as soon as symptoms are noticed.
Since hypovolemic shock is often a symptom of another emergency situation, the most important thing is to seek treatment immediately. It is also important to understand that treating shock itself will not be preventive, but can lead to additional diagnoses and treatments that can save lives.