FLUID VOLUME DEFICIT
- Dehydration occurs when the fluid intake of the body is not sufficient to meet the fluid needs of the body.
- The goal of treatment is to restore fluid volume, replace electrolytes as needed, and eliminate the cause of the fluid volume deficit.
Types of fluid volume deficits
- Water and dissolved electrolytes are lost in equal proportions.
- Known as hypovolemia, isotonic dehydration is the most common type of dehydration.
- Isotonic dehydration results in decreased circulating blood volume and inadequate tissue perfusion.
- Water loss exceeds electrolyte loss.
- The clinical problems that occur result from alterations in the concentrations of specific plasma electrolytes.
- Fluid moves fromthe intracellular compartment into the plasma and interstitial fluid spaces, causing cellular dehydration and shrinkage.
- Hypotonic dehydration
- Electrolyte loss exceeds water loss.
- The clinical problems that occur result from fluid shifts between compartments, causing a decrease in plasma volume.
- Fluid moves from the plasma and interstitial fluid spaces into the cells, causing a plasma volume deficit and causing the cells to swell.
Causes of fluid volume deficits
- Inadequate intake of fluids and solutes
- Fluid shifts between compartments
- Excessive losses of isotonic body fluids
Hypertonic dehydration—conditions that increase
- fluid loss, such as excessive perspiration, hyperventilation, ketoacidosis, prolonged fevers, diarrhea, early-stage renal failure, and diabetes insipidus
- Chronic illness
- Excessive fluid replacement (hypotonic)
- Renal failure
- Chronic malnutrition