What is hypovolemia?
Hypovolemia is the medical term for a decrease in the volume of circulating blood in the body. Hypovolemia is more commonly known as dehydration.
What causes hypovolemia?
There are several different causes of hypovolemia, including:
- Dehydration from inadequate fluid intake
- Blood loss through childbirth, injury, surgery, or trauma
- Fluid loss from diarrhea or vomiting, large burns, excessive perspiration, or medications (such as diuretics)
- Pregnancy complications, such as placenta previa
- Ruptured aortic aneurysm
- Sepsis
- Surgery.
What are the symptoms of hypovolemia?
Symptoms of the initial stages of hypovolemia include:
- Thirst
- Drying out of the mucous membranes, for example, the membranes of the mouth or nose
- Loss of elasticity of the skin
- A decrease in urine output.
The body compensates for this fluid loss by increasing the rate and strength of heart contractions and reducing blood flow to the limbs and arms in favor of the brain, heart, and kidneys.
If volume loss continues, the body loses its ability to compensate and blood pressure drops. Tissue damage begins to occur because the heart is unable to pump enough blood to vital organs to meet their needs.
Continued volume loss can lead to hypovolemic shock. This is a medical emergency and symptoms may include:
- Anxiety or confusion
- Cold, clammy skin
- Decreased or absent urine output
- Paleness
- Rapid breathing and heart rate
- Sweating
- Weakness
- Unconsciousness.
How is hypovolemia treated?
Treatment depends upon the severity of the volume loss. Treatment may include:
- Increased fluid consumption
- Intravenous fluids
- Blood or cryoprecipitate transfusions
- Intravenous colloids or crystalloids
- Platelet transfusions
- Medications to increase blood pressure and stabilize the heart rate and heart contractions, such as vasopressors
- Treatment of the underlying injury.
