Fluid Solutions and IV Fluids Quiz

Fluid Solutions & IV Fluids

• Hypotonic solution: Solute concentration lower than inside the cell; cell gains water. More dilute than blood; fluid moves out of blood vessels. Examples include 0.45% NaCl, 0.33% NaCl, 0.2% NaCl, and 2.5% dextrose in water.
• Hypertonic solution: Solute concentration greater than inside the cell; cell loses water. More concentrated than blood; fluid moves into blood vessels. Examples include 3% NaCl, 5% NaCl, and solutions with >5% dextrose.
• Isotonic solution: Solute concentration equal to that inside the cell; no net water movement. Examples include 0.9% NaCl (normal saline), Lactated Ringer's, Ringer's solution, and 5% dextrose in water.

Fluid Compartments & Pressure

• Interstitial fluid: Fluid between cells.
• Vascular fluid: Fluid within blood vessels.
• Hydrostatic pressure: Force of fluid within a compartment; higher at the arterial end of capillaries than the venous end. Cardiac output significantly influences this pressure.
• Colloid osmotic pressure: Pressure exerted by proteins (e.g., albumin) in the blood, drawing fluid into the vascular space. Plasma has significantly higher protein levels than interstitial fluid. Decreased vascular oncotic pressure can result from protein loss (renal issues, liver dysfunction, inadequate intake), while increased interstitial oncotic pressure can occur due to capillary wall damage.

Edema

• Occurs when venous hydrostatic pressure is elevated. Contributing factors include fluid overload, heart failure, liver failure, venous obstruction, and venous insufficiency. Increased tissue hydrostatic pressure also contributes.

IV Fluid Selection & Patient Examples

• Hypotonic IV fluid indication: Hypovolemia (e.g., dehydration from vomiting, diarrhea). Symptoms include thirst, low blood pressure, high heart rate, low urine output, delayed capillary refill, fatigue, skin tenting, and dry mucous membranes.
• Hypertonic IV fluid indication: Hypervolemia (e.g., edema, fluid overload). Symptoms include increased blood pressure, frequent urination, edema, shortness of breath, weight gain, bounding pulse, fatigue, and crackles in the lungs.
• Isotonic IV fluid use: In situations where fluid balance needs to be maintained, such as during planned surgeries or in cases where rapid fluid resuscitation is necessary (e.g. hemorrhage).

Older Adult Considerations

• Decreased thirst perception, increased risk of dehydration due to diuretic use, fear of falling limiting fluid intake, cognitive decline impacting fluid awareness, and incontinence may lead to decreased fluid intake.

Electrolyte Imbalances

• Hypokalemia (<3.5 mEq/L): Causes include GI losses, renal losses, skin losses (sweating), dialysis, K+ shifts into cells, and insufficient intake. Manifestations: Fatigue, muscle weakness, cramps, nausea/vomiting, paralytic ileus, paresthesias, decreased reflexes, cardiac dysrhythmias, and hyperglycemia. Often associated with metabolic alkalosis.
• Hyperkalemia (>5.0 mEq/L): Causes include excess intake, potassium-containing drugs, and shifts of potassium from intracellular to extracellular fluid (e.g., acidosis, tissue catabolism).

Precautions with Hypotonic Solutions

• Avoid in patients with increased intracranial pressure (ICP) risk due to potential for cerebral edema worsening.
• Avoid in patients with liver disease, trauma, or burns due to potential for intravascular fluid volume depletion.

Test your understanding of fluid solutions and their applications in IV therapy. This quiz covers hypotonic, hypertonic, and isotonic solutions, along with key concepts related to fluid compartments and hydrostatic pressure. Enhance your knowledge of fluid management in clinical settings.