What Is Hypovolemic Shock?
Hypovolemic shock is a life-threatening condition that results from a severe loss of blood.
It is often related to a specific injury or illness and can also result from excessive vomiting. When a person loses more than 20 percent (one-fifth) of body’s blood or fluid supply.
This severe fluid loss makes it impossible for the heart to pump a sufficient amount of blood to your body. Hypovolemic shock can lead to organ failure. This condition requires immediate emergency medical attention.
Hypovolemic shock is the most common type of shock, with very young children and older adults being the most susceptible.
Diagnosing hypovolemic shock
There are often no advance warnings of shock. Instead, symptoms tend to arise only when you’re already experiencing the condition. A physical examination can reveal signs of shock, such as low blood pressure and rapid heartbeat. A person experiencing shock may also be less responsive when asked questions by the emergency room doctor.
Heavy bleeding is immediately recognizable, but internal bleeding sometimes isn’t found until you show signs of hemorrhagic shock.
In addition to physical symptoms, your doctor may use a variety of testing methods to confirm that you’re experiencing hypovolemic shock. These include:
- echocardiogram, an ultrasound of the heart
- blood testing to check for electrolyte imbalances, kidney, and liver function
- CT scan or ultrasound to visualize body organs
- electrocardiogram to assess heart rhythm
- urinary catheter to measure the amount of urine in the bladder
- endoscopy to examine the esophagus and other gastrointestinal organs
- right heart catheterization to check how effectively the heart is pumping
Symptoms of hypovolemic shock
The symptoms of hypovolemic shock vary with the severity of the fluid or blood loss. However, all symptoms of shock are life-threatening and need emergency medical treatment. Internal bleeding symptoms may be hard to recognize until the symptoms of shock appear, but external bleeding will be visible. Symptoms of hemorrhagic shock may not appear immediately. Older adults may not experience these symptoms until the shock progresses significantly.
Some symptoms are more urgent than others.
Mild symptoms can include:
- profuse sweating
Severe symptoms, which must be taken seriously and warrant emergency medical attention, include:
- blue lips and fingernails
- rapid heart rate
- little or no urine output
- cold or clammy skin
- pale skin
- rapid, shallow breathing
- weak pulse
- loss of consciousness
The sign of external hemorrhaging is visible, profuse bleeding from a body site or area of injury.
Signs and symptoms of internal hemorrhaging include:
- chest pain
- abdominal swelling
- black, tarry stool (melena)
- blood in the urine
- abdominal pain
- blood in the stool
- vomiting blood
While some symptoms like abdominal pain and sweating can point to something less urgent like a stomach virus, you should seek immediate medical attention when seeing groupings of these symptoms together. This is especially true for the more serious symptoms. The longer you wait, the more damage can be done to your tissues and organs.
If you have any signs of hemorrhaging or of hemorrhagic shock, seek medical attention immediately.
Causes of hypovolemic shock
Hypovolemic shock results from significant and sudden blood or fluid losses within your body. Blood loss of this magnitude can occur because of:
- bleeding from the digestive tract
- significant vaginal bleeding
- bleeding from blunt traumatic injuries due to accidents
- bleeding from serious cuts or wounds
- internal bleeding from abdominal organs or ruptured ectopic pregnancy
In addition to actual blood loss, the loss of body fluids can cause a decrease in blood volume. This can occur in cases of:
- protracted and excessive vomiting
- excessive sweating
- excessive or prolonged diarrhea
- severe burns
Blood carries oxygen and other essential substances to your organs and tissues. When heavy bleeding occurs, there is not enough blood in circulation for the heart to be an effective pump. Once your body loses these substances faster than it can replace them, organs in your body begin to shut down and the symptoms of shock occur. Blood pressure plummets, which can be life-threatening.
Hypovolemic shock treatment
Once at a hospital, a person suspected of having hypovolemic shock will receive fluids or blood products via an intravenous line, to replenish the blood lost and improve circulation. Treatment revolves around controlling loss of fluid and blood, replacing what’s been lost, and stabilizing damage that both caused and resulted from the hypovolemic shock. This will also include treating the injury or illness that caused the shock, if possible.
- red blood cell transfusion
- intravenous crystalloids
- blood plasma transfusion
- platelet transfusion
Doctors may also administer medications that increase the heart’s pumping strength to improve circulation and get blood where it’s needed. These include:
Antibiotics may be administered to prevent septic shock and bacterial infections.
Close cardiac monitoring will determine the effectiveness of the treatment you receive.
Hypovolemic shock is dangerous for everyone, but it can be particularly dangerous in older adults. Older adults who experience hypovolemic shock have higher mortality rates than their younger counterparts. They have less tolerance for the shock, and earlier treatment to prevent other complications is vital. This can be made more complicated, as older adults may not show symptoms of shock until later than younger populations.
Hypovolemic shock complications
A lack of blood and fluid in your body can lead to the following complications:
- gangrene of the arms or legs
- heart attack
- damage to organs such as your kidney or brain
The effects of hypovolemic shock depend on the speed at which you’re losing blood or fluids and the amount of blood or fluids you are losing. The extent of your injuries can also determine your chances for survival. Chronic medical conditions such as diabetes, previous stroke, heart, lung, or kidney disease, or taking blood thinners like Coumadin or aspirin can increase the likelihood that you’ll experience more complications from hypovolemic shock.
Common complications of hemorrhagic shock include:
- kidney damage
- other organ damage
Some people may also develop gangrene due to decreased circulation to the limbs. This infection may lead to amputation of the affected limbs.
Recovery from hypovolemic shock depends on factors like the patient’s prior medical condition and the degree of the shock itself.
Those with milder degrees of shock will have an easier time recovering. If severe organ damage results from the shock, it can take much longer to recover, with continued medical interventions needed. In severe cases, organ damage may be irreversible.
Overall, your outlook will depend on the amount of blood you lost and the type of injury you sustained. The outlook is best in healthy patients who haven’t had severe blood loss.