IVF

Choosing the appropriate IV fluids depends on the specific needs of the patient.
Refer to Table 17.20 in the textbook for detailed guidance.

Normal plasma osmolality is between 280-295 mOsm/kg.
Hyperosmolar is defined as greater than 295 mOsm/kg (more solutes, less water).
Hypoosmolar is less than 275 mOsm/kg (fewer solutes, more water).

What They Are: Isotonic fluids are solutions that have the same amount of salt and other substances as the fluids in our cells. So, when we use these fluids, no extra water moves in or out of the cells.
Why They Matter:
- They help keep our cells the right size.
- They are used when a person doesn't have enough fluid in their body.
Common Types:
- 0.9% Sodium Chloride (Normal Saline): This is the most used isotonic fluid. It helps rehydrate the body, and it has 308 mOsm/kg (a measure of concentration).
- Lactated Ringer's: This fluid has 273 mOsm/kg and contains important minerals like sodium, potassium, and calcium. It’s helpful for people who have injuries or have lost a lot of fluids through the stomach.
- Dextrose 5% in 0.25% Sodium Chloride (D5 ¼ NS): This fluid provides some energy and salt and is also isotonic.

Have a lower osmolality than plasma, leading to cell swelling.
Key Solutions:
- 0.45% Sodium Chloride (1/2 Normal Saline) - 154 mOsm/kg. Useful for hypernatremia and slow hydration.
- Dextrose 5% in water - essentially providing free water; great for patients needing calories or hydration. Avoid fast administration.
Adverse Effects: Hyponatremia, hypotension with large volumes.

Hypertonic fluids have a higher concentration of salt than the fluids in our blood, which causes water to move out of the cells, making them shrink. Here are some important hypertonic fluids:
3% Sodium Chloride: It has a high concentration (1026 mOsm/kg) and is used for serious conditions like very low sodium levels (hyponatremia) or after a head injury.
Dextrose 10% in Water: This solution is less concentrated (556 mOsm/kg) and helps people with low blood sugar (hypoglycemia).

Warnings:

These fluids should not be given quickly; they need to be administered slowly to prevent causing high sodium levels (hypernatremia) or putting too much fluid into the body at once (overload).
It's important to check the patient's blood pressure and sodium levels because hypertonic fluids can be harmful and are best given through a special type of IV line called a central line.

Expand vascular volume.
Common Types:
- Albumin (25% solution is most common) used to pull fluid into blood vessels, preferable for cirrhosis, burns, and ascites.
- Packed Red Blood Cells - vital for blood loss, always check blood type.
Cautions:
- Monitor for fluid overload in the vasculature.
- Check blood pressure, lung sounds, and urine output.

IV fluids can be dangerous; careful monitoring is critical.
High volumes can be risky for patients with fluid clearance issues (e.g., dialysis patients, heart failure).