The body loses water all the time. A person responds to the thirst reflex by drinking fluids and eating foods that contain water. However, if water isn’t adequately replaced, the body’s cells can lose water. This causes dehydration, or fluid volume deficit. Dehydration refers to a fluid loss of 1% or more of body weight.
Signs and symptoms of dehydration include:
- extreme thirst
- dry skin and mucous membranes
- poor skin turgor
- increased heart rate
- falling blood pressure
- decreased urine output
- seizures and coma (in severe dehydration).
Laboratory values may include a serum sodium level above 150 mEq/L and serum osmolality above 305 mOsm/kg. The patient may also have an increase in his blood urea nitrogen and hemoglobin levels.
Treatment of dehydration involves determining its cause (such as diarrhea or decreased fluid intake) and replacing lost fluids — either orally or I.V. Most patients receive hypotonic, lowsodium fluids such as dextrose 5% in water (D5W).