IV Fluids: Hypotonic, Isotonic, and Hypertonic Solutions

These flashcards cover the key terms and definitions related to IV fluids, focusing on hypotonic, isotonic, and hypertonic solutions for easy study.

Osmolarity

The concentration of a solution expressed as the total number of solute particles per Liter (mOsm/L).

Osmolality

The concentration of a solution expressed as the total number of solute particles per Kilogram (mOsm/Kg).

Hypotonic solution

A solution with an osmolarity of less than 270 mOsm/Kg.

Isotonic solution

A solution with an osmolarity between 270-300 mOsm/Kg where osmotic pressure inside cells equals outside cells.

Hypertonic solution

A solution with an osmolarity greater than 300 mOsm/Kg.

Crystalloids

IV fluids that are easily mixed, clear, and can move across semi-permeable membranes (e.g., LR, D5NS).

Colloids

IV fluids composed of large molecules that do not cross semi-permeable membranes, and expand intravascular volume by drawing fluid in (e.g., albumin, propofol).

Lactated Ringer's solution

An isotonic IV solution most closely related to blood, used for electrolyte replacement and trauma patients.

D5W (5% Dextrose in Water)

An IV solution that is both isotonic and hypotonic, which provides calories but does not replace electrolytes.

Fluid overload

A condition that may result from isotonic solutions, causing symptoms such as edema and bounding pulse.

0.9% Saline (Normal Saline)

An isotonic solution used to treat low extracellular fluid; the only IV solution that can be transfused with blood.

0.45% Saline (1/2 NS)

A hypotonic solution that shifts fluids from intravascular to intracellular and interstitial spaces, hydrating cells in dehydration.

3% NaCl

A hypertonic solution used to treat symptomatic hyponatremia; closely monitored due to risks of fluid overload.