ADAM Health Encyclopedia

Hypovolemic shock

Definition

Hypovolemic shock is an emergency condition in which severe blood and fluid loss makes the heart unable to pump enough blood to the body. This type of shock can cause many organs to stop working.

Alternative Names

Causes

Losing about 1/5 or more of the normal amount of blood in your body causes hypovolemic shock.

Blood loss can be due to bleeding from cuts or other injury or internal bleeding such as gastrointestinal tract bleeding. The amount of blood in your body may drop when you lose too many other body fluids, which can happen with diarrhea, vomiting, burns, and other conditions.

The greater and more rapid the blood loss, the more severe the shock symptoms.

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

Exams and Tests

An examination indicates the presence of shock. There is usually low blood pressure, rapid pulse, and low body temperature.

Tests that may be done include:

• CBC
• CT scan or an x-ray of suspected areas
• Endoscopy
• Echocardiogram (heart ultrasound)
• Right heart (Swan-Ganz) catheterization -- can help tell the difference between hypovolemic and another type of shock called cardiogenic shock

Treatment

Get immediate medical help. In the meantime, follow these steps:

• Keep the person comfortable and warm (to avoid hypothermia).
• Have the person lie flat with the feet lifted up about 12 inches to increase circulation. However, if the person has from a head, neck, back, or leg injury, leave him or her in the position in which they were found unless doing so poses other immediate danger.
• Do not give fluids by mouth.
• If person is having an allergic reaction, treat the allergic reaction, if you know how.
• If the person must be carried, try to keep him or her flat, with the head down and feet lifted up. Stabilize the head and neck before moving a person with a suspected spinal injury.

The goal of hospital treatment is to replace blood and fluids. Anintravenous (IV) line will be put into the persons arm to allow blood or blood products to be given.

Medicines such asdopamine, dobutamine, epinephrine, and norepinephrine may be needed to increase blood pressure and the amount of blood pumped out of the heart (cardiac output).

Other methods that may be used to manage shock include:

• Cardiac monitoring, including Swan-Ganz cathertization
• Urinary catheter to collect and monitor how much urine is produced

Outlook (Prognosis)

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.

In general, patients with milder degrees of shock tend to do better than those with more severe shock. However, in cases of severe hypovolemic shock, death is possible even with immediate medical attention. The elderly are at increased risk of having poor outcomes from shock.

Possible Complications

• Kidney damage
• Brain damage

When to Contact a Medical Professional

Hypovolemic shock is a medical emergency! Call the local emergency number (such as 911) or take the person to the emergency room.

Prevention

Preventing shock is easier than trying to treat it once it happens. Prompt treatment of the underlying cause will reduce the risk of developing severe shock. Early first aid can help control shock.