Chapter 8: Fluid and Electrolyte Imbalance

Flashcards covering core concepts of electrolytes and fluids, altered balance states, cirrhosis-related fluid issues, dehydration, and hypoparathyroidism as described in the lecture notes.

What are electrolytes, and what are cations and anions?

Electrolytes are electrically charged ions in body fluids; cations are positively charged ions and anions are negatively charged ions.

What maintains electroneutrality in body fluids?

Electroneutrality is maintained by the balance of cations and anions.

What percentages describe total body water, intracellular fluid, and extracellular fluid distribution?

Total body water is about 60% of body weight; intracellular fluid (ICF) ~40%; extracellular fluid (ECF) ~20% (plasma ~5%, interstitial ~14%, transcellular ~1%).

What are the main types of fluid transport and their energy requirements?

Passive transport requires no energy; active transport requires energy (e.g., the sodium–potassium pump).

What processes govern fluid movement between compartments?

Osmosis, reabsorption, and filtration drive fluid movement.

What pressures drive fluid movement in the body?

Hydrostatic pressure and osmotic pressure.

Which mechanisms regulate fluid balance?

Thirst, the renin–angiotensin–aldosterone system (RAAS), and antidiuretic hormone (ADH).

How does tonicity affect water movement and cell size?

Isotonic: equal solute concentration; hypotonic: lower external solute causing water into the cell (swelling); hypertonic: higher external solute causing water out of the cell (shrinkage).

What are the definitions of isotonic, hypotonic, and hypertonic solutions relative to the cell?

Isotonic: equal solute concentration; hypotonic: lower outside solute; hypertonic: higher outside solute.

Name examples of electrolyte imbalances by electrolyte.

Sodium imbalances (hypo- and hypernatremia), potassium imbalances (hypo- and hyperkalemia), calcium imbalances (hypo- and hypercalcemia), among others.

What are hypovolemia and hypervolemia?

Hypovolemia is low blood volume; hypervolemia is an excess of fluid volume.

What are common causes or mechanisms of edema?

Edema results from increased hydrostatic pressure, decreased colloid osmotic pressure, increased permeability, or lymphatic obstruction.

What is cirrhosis and how does it affect fluid balance?

Cirrhosis is liver disease causing portal hypertension and altered fluid balance due to hepatocyte damage and impaired blood flow.

What are the clinical manifestations of cirrhosis-related fluid imbalance?

Ascites, abdominal discomfort, increased girth/weight, sodium retention, hyponatremia, and renal failure.

What treatments are used for cirrhosis-related fluid accumulation?

Paracentesis, diuresis, and intravenous albumin.

What is dehydration and its pathophysiology?

Dehydration is an alteration in fluid/electrolyte balance due to decreased intake or increased output; fluids may shift between compartments (e.g., ascites).

What are common clinical manifestations of dehydration?

Decreased level of consciousness, prolonged capillary refill time, dry mucous membranes, and vital sign changes.

How is dehydration treated?

Rehydration (oral or IV) and correction of electrolyte imbalance.

What is hypoparathyroidism and its pathophysiology?

Impaired parathyroid function leading to decreased blood calcium; PTH normally mobilizes calcium when levels are low.

What are the clinical manifestations of hypoparathyroidism?

Dry skin and hair, brittle nails, muscle cramps, tingling in extremities, and fatigue.

What is the treatment for hypoparathyroidism?

Calcium and vitamin D supplementation.