Hypovolemic shock
Key points
- Hypovolemic shock is a particular form of shock in which the heart is unable to supply enough blood to the body.
- Loss of approximately one-fifth or more of the normal blood volume produces hypovolemic shock.
- There is usually low blood pressure, rapid pulse, and body temperature may drop.
- Hypovolemic shock is always a medical emergency, but there is wide variation in both symptoms and outcomes depending upon the amount of blood volume lost, the rate of loss, the underlying illness or injury causing the loss, and other factors.
Alternative names
Shock - hypovolemic
Definition
Hypovolemic shock is a particular form of shock in which the heart is unable to supply enough blood to the body. It is caused by blood loss or inadequate blood volume.
Causes, incidence, and risk factors
Loss of approximately one-fifth or more of the normal blood volume produces hypovolemic shock. The loss can be from any cause, including external bleeding (from cuts or injury), gastrointestinal tract bleeding, other internal bleeding, or from diminished blood volume resulting from excessive loss of other body fluids (such as can occur with diarrhea, vomiting, burns, and so on). In general, larger and more rapid blood volume losses result in more severe shock symptoms.
In another form of shock called cardiogenic shock, there is adequate blood volume, but the heart is unable to pump the blood effectively.
Symptoms
- rapid pulse
- pulse may be weak (thready)
- rapid breathing
- anxiety or agitation
- cool, clammy skin
- weakness
- pale skin color (pallor)
- sweating, moist skin
- decreased or no urine output
- low blood pressure
- confusion
- unconsciousness
Signs and tests
An examination indicates the presence of shock. There is usually low blood pressure, rapid pulse, and body temperature may drop.
- Laboratory tests include a CBC; other tests may be performed depending on the suspected cause of the loss of volume.
- Tests may be required to determine site and cause of volume depletion, and could include a CT scan or an X-Ray of suspected areas.
- Endoscopy may be performed in cases of bleeding from the gastrointestinal tract.
- An echocardiogram (heart ultrasound) or right heart (Swan-Ganz) catheterization may show low cardiac output (pumping action), confirming shock, and may also help to differentiate between hypovolemic versus cardiogenic shock.
Treatment
Obtain professional medical care immediately! Limited measures to help include:
Written and revised by
Andrey Nailor, M.D.
Our doctors write and review articles for accuracy and keep them up to date.
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