Fluids and Electrolytes (ANRS 233) practice flashcards

A collection of vocabulary-style flashcards covering the basics of fluid composition, movement, regulation, and imbalances as presented in the ANRS 233 lecture notes.

Total body water (TBW)

The percent of body weight that consists of water.

Intracellular fluid

The majority of body fluid which is located within the cell.

Extracellular fluid

Fluid outside the cell, which can be interstitial, intravascular, or transcellular.

Solutes

Substances that dissolve in a solvent (liquid).

Crystalloids

Solutes that dissolve easily.

Colloids

Solutes that do not dissolve easily.

Electrolytes

Charged substances used to conduct electrical impulses across cells.

Osmosis

The movement of water across cell membranes.

Osmotic pressure

The force created when two solutions of different concentrations are separated by a selectively permeable membrane.

Osmolality

The number of osmols (units of osmotic pressure) per kilogram of solvent.

Osmolarity

The number of osmols per liter of solvent.

Tonicity

The level of osmotic pressure of a solution.

Metabolism Fluid Output

Water produced by living cells as a by-product of oxidative metabolism, totaling $300\,mL$ daily.

Renin–angiotensin–aldosterone system (RAAS)

A regulatory system involving the liver, kidneys, lungs, and adrenal glands to maintain blood pressure and fluid volume.

ACE (angiotensin-converting enzyme)

An enzyme released from the lungs that acts on angiotensin I to form angiotensin II.

Angiotensin II

A substance that acts directly on blood vessels to stimulate vasoconstriction and on the adrenal gland to stimulate release of aldosterone.

Aldosterone

A steroid hormone produced by the adrenal cortex known as a "salt saver" that causes the kidneys to reabsorb sodium ($NaCl$) and water ($H_2O$).

ADH (Antidiuretic Hormone)

A peptide hormone produced by the hypothalamus and stored in the posterior pituitary that acts as a "water saver" by directly reabsorbing water in the kidneys.

Osmoreceptors

Sensors that monitor the osmolarity of blood plasma.

Isotonic Imbalance

A condition where $H_2O$ and $Na^+$ are lost or gained in equal proportion.

Edema

The abnormal accumulation of fluid in the interstitial spaces.

Hypernatremia

A water deficit caused by the loss of more water than salt or the gain of more salt than water.

Hyponatremia

A water excess caused by the gain of more water than salt or the loss of more salt than water.

$16$ to $18$ gauge Needle

Catheter sizes commonly used for trauma, surgery, rapid infusion of fluids, and blood transfusions.

$20$ to $22$ gauge Needle

Catheter sizes commonly used for general and intermittent infusions and blood transfusions.

Central venous catheter

A catheter inserted into a major vein in the arm or chest with the tip lying in the superior vena cava.

Non-tunneled lines

Central lines that go straight into a vein and are intended for short-term use (days).

Tunneled lines

Central lines routed under the skin before entering the vein to reduce infection risk and allow for long-term use (months to years).

Extravasation

The escape of a vesicant medication into the surrounding tissue, often caused by a cannula puncturing the vein wall or leaking at the insertion site.

Systemic IV complications

Serious issues associated with IV therapy including fluid overload, speed shock, and embolism.