Fluid Volume Deficit Overview

Fluid Volume Deficit (FVD)

• FVD: Decrease in intravascular, interstitial, or intracellular fluid. Also known as hypovolemia.
• Hypovolemia is a loss of water and electrolytes, decreasing circulating volume and extracellular fluid. Loss of electrolytes can cause dehydration (loss of water and increased sodium). Hypernatremia (high sodium) is a potential complication.
• FVD develops gradually or rapidly, depending on the cause.
• Causes of FVD include trauma (like hemorrhage), nausea/vomiting, diarrhea, GI suctioning, ileostomies, laxative abuse, diuretic use, heavy sweating, renal disorders, insensible fluid loss, heat-related losses, and insufficient fluid intake (especially in those dependent on others). Severe burns also cause considerable fluid loss (third-spacing).
• Fluid Shifts: Accumulation of fluid in a tissue or body cavity (third-spacing). Fluid is drawn from circulating blood volume, resulting in a pseudo-fluid volume loss. This trapped fluid is unavailable for normal bodily functions. Examples include ascites (abdomen) due to liver disease and excess fluid around lungs from pulmonary edema. Thoracentesis may be needed to remove excess fluid.

Tonicity

• Tonicity describes the concentration of electrolytes relative to water.
• Isotonic: Equal amounts of water and sodium are lost (e.g., NaCl/LR solutions).
• Hypertonic: More sodium than water is lost, causing cells to shrink.
• Hypotonic: Less sodium than water is lost, causing cells to swell.

Fluid Volume Deficit Risk Factors

• Factors that prevent normal intake
• Factors leading to increased fluid loss (vomiting/diarrhea/burns/hemorrhage/renal failure)
• NPO status, dysphagia, lack of access to fluids, inaccuracies in fluid replacement, and additional risk factors like illness, burns, increased sweating, elevation, and environmental stressors.

Fluid Volume Deficit Prevention

• Adequate fluid intake to replace losses.
• Address additional risk factors. This includes factors affecting the ability to take in fluids or causing increased loss like infection, high temperatures, elevated altitudes, etc.

Fluid Volume Deficit Clinical Manifestations

• Early signs: Thirst; neurological - weakness, altered mental status, decreased level of consciousness; cardiac - tachycardia(fast heart rate), hypotension (low blood pressure), orthostatic hypotension; respiratory - tachypnea (fast breathing); renal - decreased urine output, dark urine; GI - constipation; muscular - fatigue, weakness, skin tenting (skin stays up when pinched), dry mucous membranes, poor skin turgor, cool/pale extremities, sunken eyes, muscle cramps, loss of thirst, potential coma.

• Diagnostics: Daily weights (loss equals fluid loss), CMP (serum electrolyte panel- including sodium, potassium, creatinine and blood urea nitrogen = elevated in dehydration and kidney function problems), glucose (low with dehydration)), Urine specific gravity (higher means more dehydrated), CBC (hematocrit elevation from concentrated blood).

Fluid Volume Deficit Treatment

• Oral rehydration: Water, sports drinks, or Pedialyte for minor loss.
• IV fluids: Normal Saline or Lactated Ringer's solutions for severe or non-tolerable losses (needed if patient can't take oral hydration). IV fluid choices depend on patient's individual needs and condition.

Fluid Volume Deficit Lifespan Considerations

• Infants and children: Higher body surface area, increased insensible fluid loss, immature kidneys, susceptible to vomitting/diarrhea. Assessment findings include dry mucous membranes, poor skin turgor, fewer wet diapers, sunken eyes, and depressed fontanelles.
• Pregnant women: Morning sickness, miscarriage, or hemorrhage.
• Older adults: Often have issues with thirst perception, altered mentation, decreased access to fluids, and medication issues.

Nursing Process for FVD

• Assessment: Daily weights are critical indicators of fluid status. Assess intake and output, medication use, recent illness, prior conditions, risk factors, orthostatic hypotension, skin condition (color, tenting, turgor), level of consciousness (LOC), urine characteristics (color, output).
• Analysis/Problem Identification: Risk for injury, fluid volume deficit, ineffective peripheral tissue perfusion, dehydration, decreased circulatory volume, decreased perfusion, decreased LOC.
• Planning: Promote fluid balance, oral fluid intake (1500-2000 mL/day), recognize and address any underlying causes, evaluate and document.
• Implementation: Daily weights, I&O records, frequent vital signs, monitor labs, teach patient/family, support adequate oral intake.
• Evaluation: Electrolyte balance (including sodium and potassium), normal urine output, adequate fluid intake, normal vital signs.