Lecture Notes: Colloids vs. Crystalloids

Overview

• Purpose: Review colloids and crystalloid solutions.
• Administration: Both types are administered intravenously (IV) to expand plasma volume by adding fluid to intravascular space (blood vessels).

Colloid Solutions

• Types:
  • Natural: Albumin
  • Synthetic: Dextran, Hydroxyethyl starches, Gelatin
• Mechanism:
  • Contain large molecules that remain in the intravascular space.
  • Increase oncotic (colloidal osmotic) pressure, pulling water from interstitial fluid into the blood vessels.
• Uses:
  • Hypovolemic shock, severe burns, severe bleeding
• Advantages:
  • Rapid plasma volume expansion
  • Amount administered typically equal to fluid loss
• Disadvantages:
  • Risk of allergic reactions and coagulation problems
  • Less accessible and more expensive

Crystalloid Solutions

• Types: Hypertonic, Hypotonic, Isotonic
• Components: Smaller molecules (electrolytes)
• Mechanism:
  • Do not stay long in intravascular space, requiring large amounts to replace fluid loss
  • Risk of fluid volume overload
• Types and Effects:
  • Hypertonic Solutions: High solute concentration; pulls water from cells, used for conditions like cerebral edema.
  • Hypotonic Solutions: Low solute concentration; causes cells to absorb water, useful for dehydrated cells but can cause cell swelling and rupture.
  • Isotonic Solutions: Equal solute concentration to blood; expands intravascular space without large fluid shifts.
• Advantages:
  • No allergic reactions or coagulation issues
  • Easily accessible and less expensive

Conclusion

• Crystalloids and colloids have unique properties and uses.
• Further detailed lectures available through provided resources.