Hypovolemia

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Hypovolemia is a decrease in blood volume, more accurately a decrease in plasma volume. Hypovolemia is also know as oligemia or shock. Hypovolemic shock can occur very quickly & needs urgent medical intervention to prevent damage to the cardiovascular, gastrointestinal, renal and respiratory systems.

Causes: Blood loss (hemorrhage), ingestion of anti-coagulents, loss of plasma (severe burns or lesions losing fluid), loss of sodium by excessive sweating, diarrhea & vomiting causing dehydration, vasoldilation (widening of blood vessels). Often, no symptoms appear until whole blood volume falls by 10-20%.

Symptoms: Tachycardia (fast heart rate) or a very weak pulse, pale skin, lips, gums & slow capillary refill, low blood pressure, extreme weakness & lethargy, panting/hyperventilation, hemorrhage including gastro-intestinal bleeding, cold feet & extremities.

Diagnosis: Finding the cause is vital. Imaging may be needed to find the source of any suspected internal bleeding, ECG (electro-cardiogram) & cardiac imaging to assess heart problems, blood pressure reading, electrolyte analysis.

Treatment: Long-term shock can lead to severe cardiac system damage, even cardiac arrest. Fluids must be given immediately to restore blood circulation volume & electrolytes. Anemia may result, as well as low protein levels. A blood transfusion may be also be required. Hypotensive resuscitation is given for hypovolemic shock due to bleeding which increases blood pressure, but caution must be taken not to disturb any clot that may be forming by increasing blood pressure too much. Surgery may be required after patient has been stabilised to stop internal bleeding.

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