Fluid volume deficit (also known as deficient fluid volume or hypovolemia) describes the loss of extracellular fluid from the body. Extracellular fluid is the body fluid not contained within individual cells. It constitutes about 20% of our body weight and includes blood plasma, lymph, spinal cord fluid, and the fluid between cells. Importantly, this fluid isn’t just water—it also contains electrolytes and other essential solutes.
Monitor for the existence of factors causing deficient fluid volume (e.g., gastrointestinal losses, difficulty maintaining oral intake, fever, uncontrolled type II diabetes mellitus, diuretic therapy). Early identification of risk factors and early intervention can decrease the occurrence and severity of complications from deficient fluid volume. The gastrointestinal system is a common site of abnormal fluid loss.
Watch for early signs of hypovolemia, including weakness, muscle cramps, and postural hypotension. Late signs include oliguria; abdominal or chest pain; cyanosis; cold, clammy skin; and confusion.
Fluid volume deficit is often used interchangeably with the term “dehydration,” but they aren’t exactly the same thing. Dehydration refers specifically to the loss of body water as opposed to body fluid.What’s the difference? Electrolytes. If a patient has just lost water but no electrolytes, they’ll have slightly different issues—and require slightly different treatment—than a patient who has lost wholesale body fluids, which contains water and electrolytes
Monitor total fluid intake and output every 8 hours and every hour for the unstable client.
Watch trends in output for 3 days; include all routes of intake and output and note color and specific gravity of urine. Monitoring for trends for 2 to 3 days gives a more valid picture of the client’s hydration status than monitoring for a shorter period. Dark-colored urine with increasing specific gravity reflects increased urine concentration.
Monitor daily weight for sudden decreases, especially in the presence of decreasing urine output or active fluid loss. Weigh client on same scale with same type of clothing at same time of day, preferably before breakfast. Body weight changes reflect changes in body fluid volume. A 1-pound weight loss reflects a fluid loss of about 500 cc.
Monitor vital signs of clients with deficient fluid volume every 15 minutes to 1 hour for the unstable client and every 4 hours for the stable client. Observe for decreased pulse pressure first, then hypo tension, tachycardia, decreased pulse volume, and increased or decreased body temperature. A decreased pulse pressure is an earlier indicator of shock than is the systolic blood pressure. Decreased intramuscular volume results in hypo tension and decreased tissue oxygenation. The temperature will be decreased as a result of decreased metabolism, or it may be increased if there is infection or hyperglycemia present.
Check orthostatic blood pressures with client lying, sitting, and standing. A 15 mm Hg drop when upright or an increase of 15 beats/minute in the pulse rate are seen with deficient fluid volume.
Monitor for inelastic skin turgid, thirst, dry tongue and mucous membranes, longitudinal tongue furrows, speech difficulty, dry skin, sunken eyeballs, weakness, and confusion. Tongue dryness, longitudinal tongue furrows, dryness of the mucous membranes of the mouth, upper body muscle weakness, thirst, confusion, speech difficulty, and drunkenness of eyes are symptoms of deficient fluid volume.
Provide frequent oral hygiene, at least twice a day. Oral hygiene decreases unpleasant tastes in the mouth and allows the client to respond to the sensation of thirst.
Provide fresh water and oral fluids preferred by client, provide prescribed diet; offer snacks, instruct significant other to assist client with feedings as appropriate. The oral route is preferred for maintaining fluid balance. Distributing the intake over the entire 24 hour period and providing snacks and preferred beverages increases the likelihood that the client will maintain the prescribed oral intake.
Provide free water with tube feedings as appropriate. This provides water for replacement of intramuscular or intracellular volume as necessary. Tube feeding has been found to increase the risk for dehydration.
Institute measures to rest the bowel when client is vomiting or has diarrhea,. Hydrate client with ordered IV solutions if prescribed. The most common cause of deficient fluid volume is gastrointestinal loss of fluid. At times it is preferable to allow the gastrointestinal system to rest before resuming oral intake.
Provide oral replacement therapy as ordered with a glucose-electrolyte solution when client has acute diarrhea or nausea or vomiting. Provide small, frequent quantities of slightly chilled solutions. Maintenance of oral intake stabilizes the ability of the intestines to digest and absorb nutrients; glucose-electrolyte solutions increase net fluid absorption while correcting deficient fluid volume.
Administer antidiarrheals and antiemetics as appropriate. The gastrointestinal tract is a common site for fluid loss. The goal is to stop the loss that results from vomiting or diarrhea.
If client requires IV fluid replacement, maintain patent IV access, set an appropriate IV infusion flow rate, and administer at a constant flow rate as ordered. Isotopic IV fluids such as 0.9% N/S or lactated ringers allow replacement of intramuscular volume.
Assist with ambulation if client has postural hypotension. Postural hypotension can cause dizziness, which places the client at higher risk for injury.
Promote skin integrity (e.g., monitor areas for breakdown, ensure frequent weight shifts, prevent shearing, promote adequate nutrition). Deficient fluid volume decreases tissue oxygenation, which makes the skin more vulnerable to breakdown.