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

Shock - hypovolemic

Causes, incidence, and risk factors

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
• Bleeding from other injuries
• Internal bleeding, such as in the gastrointestinal tract

The amount of circulating blood in your body may drop when you lose too many other body fluids, which can happen with:

• Burns
• Diarrhea
• Vomiting

Symptoms

• Anxiety or agitation
• Cool, clammy skin
• Confusion
• Decreased or no urine output
• General weakness
• Pale skin color (pallor)
• Rapid breathing
• Sweating, moist skin
• Unconsciousness

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

Signs and tests

An examination shows signs of shock, including:

• Low blood pressure
• Low body temperature
• Rapid pulse

Tests that may be done include:

• Complete blood count (CBC)
• CT scan or x-ray of suspected areas
• Echocardiogram
• Endoscopy
• Right heart (Swan-Ganz) catheterization

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 about 12 inches to increase circulation. However, if the person has a head, neck, back, or leg injury, do not change the person's position unless he or she is in 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. 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. An intravenous (IV) line will be put into the person's arm to allow blood or blood products to be given.

Medicines such as dopamine, 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:

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

Expectations (prognosis)

Hypovolemic shock is always a medical emergency. However, symptoms and outcomes can vary depending on:

• Amount of blood volume lost
• Rate of blood loss
• Ilness or injury causing the loss

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

Complications

• Kidney damage
• Brain damage

Calling your health care provider

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. Quickly treating the cause will reduce the risk of developing severe shock. Early first aid can help control shock.

References

Elbers PW, Ince C. Mechanisms of critical illness--classifying microcirculatory flow abnormalities in distributive shock. Crit Care. 2006;10:221.

Cottingham CA. Resuscitation of traumatic shock: a hemodynamic review. AACN Adv Crit Care. 2006;17:317-326.

Spaniol JR, Knight AR, Zebley JL, Anderson D, Pierce JD. Fluid resuscitation therapy for hemorrhagic shock. J Trauma Nurs. 2007;14:152-156.

Tarrant AM, Ryan MF, Hamilton PA, Bejaminov O. A pictorial review of hypovolaemic shock in adults. Br J Radiol. 2008;81:252-257.

den Uil CA, Klijn E, Lagrand WK, Brugts JJ, Ince C, Spronk PE, Simoons ML. The microcirculation in health and critical disease. Prog Cardiovasc Dis. 2008;51:161-170.