Fluid and Electrolytes Flashcards

Flashcards covering key vocabulary and concepts related to fluid and electrolyte balance in the body.

Intracellular fluid (ICF)

Fluid within cells.

Extracellular fluid (ECF)

Fluid outside cells; includes intravascular fluid (plasma), interstitial fluid, and transcellular fluid.

Intravascular fluid (plasma)

The liquid part of blood or lymph.

Interstitial fluid

Fluid between cells.

Transcellular fluid

A type of extracellular fluid that includes cerebrospinal fluid, synovial fluid in joints, etc.

Solvent

Liquids that hold a substance in solution.

Solute

Substances that are dissolved in a solution.

Crystalloid

Electrolytes; ability to become charged ions when dissolved in a solution.

Colloid

Non-Electrolytes; do not hold an electrical charge

Passive Transport

Fluid and electrolyte movement that requires no energy (e.g., osmosis, filtration, diffusion).

Osmosis

A passive process; Diffusion of water across a semipermeable membrane from less concentrated to more concentrated.

Filtration

A passive process; Movement of water and small solutes from an area of high pressure to an area of low pressure.

Diffusion

A passive process; Solute moves from higher concentration to lower concentration.

Active Transport

Fluid and electrolyte movement that requires energy expenditure for movement of solutes against a concentration gradient, such as the sodium/potassium pump using ATP.

Osmolality

The concentration of solutes creating pressure in a solution.

Isotonic Solutions

Solutions with the same osmolality as blood (e.g., 0.9 NS, LR, Plasma-Lyte); Stays where I put it.

Hypotonic Solutions

Solutions with lower osmolality than blood (e.g., 1/4 NS, 1/2 NS); Goes OUT of the vessel.

Hypertonic Solutions

Solutions with higher osmolality than blood (e.g., 3% NS, 5% NS); ENTERS the vessel.

Third Spacing

Fluid is trapped in a 3rd compartment fluid leaves circulation and leaks into interstitial or transcellular space where it is nonfunctional s/sx of fluid volume deficit/dehydration but without weight loss. Secondary to burns/trauma/surgery, Liver and Kidney failure.

ADH (Antidiuretic Hormone)

Retain water in renal tubes and peripheral vasoconstriction that increases BP. More ADH is released = kidneys retain fluid. Less ADH is released = more fluid is excreted.

Aldosterone

Hormone that stimulates the adrenal cortex to release aldosterone, which causes the reabsorption of sodium (and thus water retention) and excretion of potassium.

PTH (Parathyroid Hormone)

Increased PTH causes increased blood calcium levels with decreased blood phosphorus levels.

Fluid Volume Deficit (FVD)

Hypovolemia; Too little fluid in the vascular space. “Dehydration” Caused from: Fluid Shift: Third Spacing / edema, Burns/trauma/liver failure. Excess Fluid Loss: Vomiting, Diarrhea, GI suctioning, Sweating (prolonged/excessive). Decreased intake.

Fluid Volume Excess (FVE)

Hypervolemia; Too much fluid in the vascular space. Fluid overload can cause cerebral edema, delirium, heart failure, pulmonary edema and multiorgan failure. Caused from: Heart failure, Kidney failure, Excess intake of salt, Excess infusion of IV fluids

Sodium (Na+)

Normal range: 135-145 mEq/L. Maintains appropriate extracellular fluid osmolality, regulates extracellular fluid volume, aids impulse transmission in nerves and muscles, and is regulated by Aldosterone and ADH.

Hyponatremia

Serum sodium <135 mEq/L. Causes: Loss of Sodium, Diuretics / meds, GI fluids, Too much insulin/ Renal disease/Hyperglycemia.

Hypernatremia

Sodium level >145 mEq/L. Causes: Fluid deprivation, Heat stroke, Hypertonic enteral feedings without adequate water.

Potassium (K+)

Normal range: 3.5-5.0 mEq/L. Major cation in the ICF (inside the cell), directly affects cardiac muscle contraction and electrical conductivity, aids neuromuscular transmission of nerve impulses, controls intracellular osmolality

Hypokalemia

Potassium level <3.5 mEq/L (CALL MD IF LEVELS BELOW 2.5MEQ/L. CRITICAL). Causes: Too much insulin, Excessive Fluid loss, GI LOSS, Limited intake of potassium, Low levels of magnesium.

Hyperkalemia

Potassium level >5.5 mEq/L. Causes: Decreased renal function, Uncontrolled Diabetes, Excessive oral or IV intake of K+

Calcium (Ca+)

Normal Range: 8.5 to 10.5 mEq/dL; Enhances bone strength and durability, has a sedative affect on neuromuscular system, Affects activation, excitation, and contraction of cardiac and skeletal muscles, Aids in blood clotting.

Hypocalcemia

Calcium level <8.5 mEq/dL. Causes: Hypoparathyroidism (PTH), Inadequate intake of Ca+, Malnutrition (decrease in protein/albumin).

Hypercalcemia

10.5 mEq/dl; Causes: HYPERPARATHYROIDISM, MALIGNANCIES, IMMOBILITY, THIAZIDE DIURETICS (RETAIN CA+), LOW VIT. D (INDIRECTLY)

Magnesium (Mg+)

Normal Range: 1.6- 2.6 MEQ/L; Maintains normal intracellular levels of potassium, Helps maintain electric activity in nervous tissue and muscle membranes (including the heart), Affects peripheral vasodilation (Blood Pressure).

Hypomagnesemia

Magnesium level <1.6 mEq/L. Causes: NG tube suction, Malabsorption, Chronic Alcoholism, Poor nutrition

Hypermagnesemia

Magnesium Level >2.5 MEQ/L; Causes: Renal failure, Excess administration of magnesium to treat hypertension during pregnancy, Excessive use of magnesium-containing laxatives or antacids

Phosphorus

Normal Range: 2.5 to 4.5 MEQ/DL; Major component in bones and teeth, Functions in cellular metabolism to promote energy transfer to cells (ATP), Major role in acid-base balance through its actions as a urinary buffer.

Chloride (Cl)

Normal Range: 95-105 MEQ/L; Levels increase and decrease simultaneously with sodium levels. Most abundant anion in the extracellular fluid (ecf) Usually found in the form of nacl Essential to produce gastric secretions