IV Fluids Flashcards
What are crystalloids, and what are their primary components?
- Crystalloids are solutions containing small molecules that easily pass through vascular membranes.
- Common components: water, electrolytes (e.g., sodium, chloride), and sometimes glucose.
- Examples: 0.9% saline (normal saline), Hartmann’s solution, and 5% dextrose.
What distinguishes colloids from crystalloids?
- Colloids contain larger molecules (e.g., proteins or starches) that remain in the vascular space longer.
- Examples: albumin, hydroxyethyl starch (HES), and gelatins.
- Colloids are used for volume expansion but are more expensive and have a higher risk of complications.
What are the components of Hartmann’s solution, and when is it used?
- Components: Sodium, potassium, chloride, calcium, and lactate.
- Indications: Fluid resuscitation, electrolyte replacement, and correction of metabolic acidosis.
- Avoid in: Severe hyperkalemia or liver failure (due to impaired lactate metabolism).
List common indications for IV fluid therapy.
- Resuscitation: To restore circulating volume in hypovolemia or shock.
- Maintenance: To replace daily fluid and electrolyte requirements.
- Replacement: To correct specific deficits (e.g., from dehydration, vomiting, diarrhea).
- Special: Parenteral nutrition or specific conditions like hypertonic saline in hyponatremia.
What are the potential complications of IV fluid therapy?
- Volume overload: Pulmonary edema, peripheral edema.
- Electrolyte imbalances: Hypernatremia, hyponatremia, hyperkalemia.
- Acid-base disturbances: Metabolic acidosis (from 0.9% saline) or alkalosis (from excess bicarbonate).
- Infection: Related to IV access.
- Allergic reactions: More common with colloids.
Why is normal saline considered “isotonic,” and when is it commonly used?
- Isotonic because its osmolality is similar to plasma (~308 mOsm/L).
- Indications: Hypovolemia, metabolic alkalosis, and hyponatremia.
- Complication: Risk of hyperchloremic metabolic acidosis with large volumes.
What are the key uses of 5% dextrose in water (D5W)?
- Indications: Treat dehydration (when water is needed without electrolytes) or hypoglycemia.
- Complications: Can cause hyponatremia if used in excess due to dilutional effects.
How do you decide between crystalloids and colloids?
- Crystalloids: First-line for most indications (cheaper, fewer risks).
- Colloids: Reserved for specific cases like severe hypoalbuminemia or when rapid volume expansion is critical.
What are the differences between hypotonic and hypertonic solutions?
- Hypotonic: Lower osmolality than plasma (e.g., 0.45% saline). Used for intracellular dehydration.
- Hypertonic: Higher osmolality than plasma (e.g., 3% saline). Used cautiously for severe hyponatremia or cerebral edema.
What are crystalloids?
Solutions of small molecules that pass through vascular membranes.
Name 3 common crystalloid solutions.
Hartmann’s, 0.9% saline, and 5% dextrose.
What are isotonic crystalloids?
Solutions with an osmolality similar to plasma (e.g., Hartmann’s, 0.9% saline).
When are hypotonic crystalloids used?
Treating intracellular dehydration (e.g., 0.45% saline).
What is hypertonic saline used for?
Managing cerebral edema or severe hyponatremia.
What are colloids?
Fluids containing large molecules, remaining in the vascular space.
What are the risks of colloid use?
Allergic reactions, coagulopathy, and kidney injury.
When is albumin typically used?
Hypoalbuminemia, burns, or large-volume paracentesis.
Why are colloids not first-line in shock?
High cost and risk of adverse effects without clear survival benefit.
What are the main components of Hartmann’s solution?
Sodium, potassium, chloride, calcium, and lactate.
What is lactate in Hartmann’s metabolized into?
Bicarbonate, helping correct acidosis.
When should Hartmann’s be avoided?
Hyperkalemia or liver failure.
Is Hartmann’s suitable for blood transfusions?
No, due to calcium content that can cause clotting in blood products.
Why is Hartmann’s a balanced solution?
Electrolyte composition is closer to plasma than 0.9% saline.
What is the pH of 0.9% saline?
~5.5, slightly acidic.
