Fluid and Electrolytes Lecture: Unit 4

Vocabulary-style flashcards covering the composition, movement, and imbalances of body fluids and electrolytes, including normal lab values and assessment grading scales.

Total body water (TBW)

The total amount of water in the body, which comprises intracellular and extracellular fluids.

Intracellular fluid

Fluid contained within the cells of the body.

Extracellular fluid

Body fluid located outside the cells; it can be classified as interstitial, intravascular, or transcellular.

Crystalloids

Solutes that can be divided into hypotonic, isotonic, and hypertonic solutions based on their tonicity.

Colloids

Solutions containing protein or starch particles that remain intact and are unable to pass through the capillary membrane; they help re-establish circulating volume and oncotic pressure.

Osmosis

The movement of fluids back and forth through cell walls and vessel walls to maintain homeostasis.

Diffusion

The movement of solutes from an area of higher concentration to an area of lower concentration.

Hypotonic (Concentration)

A fluid containing fewer particles compared to the amount of fluid.

Isotonic (Concentration)

A fluid with an equal ratio of fluid to particles.

Hypertonic (Concentration)

A fluid containing more particles than fluid.

Hypervolemic

A state of having more fluid relative to the number of particles.

Hypovolemic

A state of having less fluid relative to the number of particles.

Major Cations

Positively charged electrolytes including Sodium ($Na^+$), magnesium ($Mg^+$), potassium ($K^+$), calcium ($Ca^{2+}$), and hydrogen ($H^+$).

Major Anions

Negatively charged electrolytes including Chloride ($Cl^-$), bicarbonate ($HCO_3^-$), and phosphate ($PO_4^{3-}$).

Hyponatremia

A serum sodium level less than $135\,MEQ/L$; symptoms include confusion, lethargy, muscle cramping, and seizures.

Hypernatremia

A serum sodium level greater than $145\,MEQ/L$; symptoms include thirst, dry sticky mucous membranes, and decreased LOC.

Hypokalemia

A serum potassium level below $3.5\,MEQ/L$; characterized by weak irregular pulses, muscle weakness, and abdominal signs like decreased peristalsis.

Hyperkalemia

A serum potassium level greater than $5.0\,MEQ/L$; symptoms include anxiety, irritability, muscle weakness, and potential cardiac arrest.

Hypocalcemia

A serum calcium level below $9\,MG/DL$; signs include hyperactive reflexes, muscle cramps progressing to tetany, and positive Trousseau’s and Chvostek’s signs.

Hypercalcemia

A serum calcium level greater than $10.5\,MG/DL$; symptoms include lethargy, stupor, pathological fractures, and kidney stones.

Hypomagnesemia

A serum magnesium level below $1.5\,MEQ/L$; characterized by neuromuscular irritability, tremors, and increased reflexes.

Hypermagnesemia

A serum magnesium level greater than $2.5\,MEQ/L$; signs include a warm flushed appearance, decreased deep tendon reflexes, and respiratory depression.

Trousseau’s and Chvostek’s signs

Positive clinical indicators often associated with hypocalcemia or hypomagnesemia.

Fluid-to-Weight Equivalence

A change of $1\,kg$ ($2.2\,lb$) is equivalent to $1\,L$ ($1000\,mL$) of fluid.

1+ Edema

Slight indentation ($2\,mm$) that returns to normal fairly quickly.

2+ Edema

Deeper indentation ($4\,mm$) that lasts longer than a 1+ grade.

3+ Edema

Obvious indentation ($6\,mm$) that lasts for several seconds.

4+ Edema

Deep indentation ($8\,mm$) that remains for several minutes.

Skin Turgor in Fluid Deficit

An assessment finding where pinched skin remains tented after release.

Fluid Restriction Management

Allocating $50\%$ of the allowed fluid amount during the day when the client is most active and consumes two meals.

IV Infiltration Grade 4

Includes tight, leaking skin, deep pitting edema, circulatory impairment, and moderate to severe pain; typically considered extravasation.