Crystalloids vs Colloids

Comparison of Crystalloids and Colloids

Feature	Crystalloids	Colloids
Definition	Fluids with small molecules (e.g., salts, sugars) that pass easily through cell membranes.	Fluids with large molecules (e.g., proteins, starches) that stay in blood vessels.
How They Work	Quickly spread to blood vessels and tissues to hydrate and balance electrolytes.	Stay in blood vessels longer, pulling fluid in to increase blood volume.
Examples	Normal Saline (0.9% NaCl), Ringer's Lactate, 5% Dextrose (D5W).	Albumin (5% or 25%), Hetastarch (Hespan), Dextran.
Uses	Dehydration, electrolyte imbalance, mild shock.	Severe shock, major blood loss, low protein states.
Where They Stay	Distribute to both blood vessels and tissues.	Mostly stay in blood vessels.
Cost	Cheaper and widely available.	More expensive.
Side Effects	Fewer side effects, less risk of allergies.	Risk of allergic reactions or clotting issues; requires close monitoring.
Key Nursing Point	Used for routine hydration; monitor for fluid overload.	Used in emergencies; watch for allergic reactions or breathing issues.