Test #1 Flashcards
Describe hypotonic vs hypertonic solutions
- Hypotonic solutions have less solutes outside of the cell, so fluids rush into the cell to try and even out the concentration.
- Hypertonic solutions have more solutes outside of the cell, so fluids leave the cell and move to the lower concentration.
What are 3 examples of hypertonic solutions
- 3% NS
- 5% NS
- 5% dextrose in 0.9% saline (D5NS)
- 5% dextrose in 0.45% saline
- 5% dextrose in LR
What are 2 examples of isotonic solutions
- LR
- 0.9% normal saline
What are 3 examples of hypotonic solutions
- 0.45% normal saline
- 2.5% dextrose in water
- 0.33% normal saline
Why would we want to give hypotonic and hypertonic solutions for high and low levels of sodium.
- Hypertonic goes with hyponatremia (pulls sodium back into your vascular system)
- Hypotonic goes with hypernatremia (pushes sodium back into your cells)
What should I remember about D5W
It’s technically an isotonic solution, but the body will metabolize the dextrose, which then turns into a hypotonic solution. (wants dextrose is absorbed, you’re left with just water = hypotonic).
Why would someone receive an isotonic solution
- We want to replace the extracellular fluid (without doing anything to the cells)
Can be caused by blood loss, D/V, dehydration
What is a good way to remember hypotonic
Think of tonic as the as the solution, and the hypo is stating that there is a low amount of solutes in the solution. This means the fluid will want to move to where it’s more concentrated - which is inside the cell. (the solution contains lower concentration of salt or solute than inside the cell)
- They also have a lower osmolality (less concentrated)
When might we give a hypotonic solution
(When there is cellular dehydration - we want water to go into the cells)
- DKA (because there is so much sugar in the blood, water is being pulled out of cells to try and balance, so we want to dilute these)
- Hyperglycemia (because of the reason above)
When do you not want to give a hypotonic solution 3
- Do not give to a patient with increased intercranial pressure, because it can cause fluid to go into the brain and swell. (basically don’t give to someone with a head injury)
- Do not give to burn victims
- Do not give to trauma patients
- Hypovolemia
(we don’t want to deplete their extracellular fluid volume any further)
If I don’t remember the names of the fluids, what’s a good way to determine if a fluid is hypertonic or hypotonic.
Hypertonic fluids will have a higher number like 5% or 10%, while hypotonic fluids will have a lower number like 0.45% (because they’re diluted).
What can hypertonic solutions cause
Fluid overload - because you’re pulling all of the fluid out of your cells and putting it into your vascular system
Why would we give a hypertonic solution
- Hypovolemia (want to move fluid into the blood vessels)
- Cerebral edema (helps to take fluid off of the brain)
What is the difference between crystalloid and colloid solutions
Crystalloids contain small molecules like electrolytes, while colloids contain large proteins and fats.
What are our crystalloid solutions
Our isotonic, hypertonic and hypotonic solutions
What do colloids do
Because of their size, they pull fluid into the blood vessels (these are our volume expanders)
If a patient has 1 liter of blood loss, how much of a crystalloid will they need to replenish that loss
3L (because the crystalloids will also go out into the space, they won’t just stay in the vessel)
What are side effects of LR 4
- Dilutes hemoglobin
- May cause hyperchloremic acidosis (caused by the chloride)
- May cause electrolyte imbalance
- Proinflammatory in large doses
Why do we want to give colloids
Because we want fluid to stay in the vascular system and not leak out (the large molecules in colloids pull and keep fluid in the blood vessels)
Because colloids stay in the blood vessels, how much colloid solution would we need if we lost 1L of blood
We will only need 1L of colloids (it’s in a 1:1 ratio)
What are examples of colloids 5
- 5% albumin (this is the main one)
- 25% albumin
- Dextran 40
- Dextran 70
- Hydroxyethyl starches
Why are colloids not given very often
They’re expensive - so we like to give crystalloids first
Because crystalloids do not stay in the blood vessels, like colloids, what ratio should crystalloids be given in.
3L of crystalloids for every 1L of blood loss.
What is albumin used for
Volume expansion - so it’s used to treat hypovolemia, burns, ascites and hepatic failure.