Fluid Therapy Flashcards
How do you calculate total body water?
TBW= BW X 0.65
because the body is 65% water.
The body is made of 65% water. There are two main compartments in which this water is contained. What are these compartments and how much water is within each?
1) intracellular (2/3)
2) extracellular (1/3)
- interstitial (75%)
- intravascular (24%)
What is the general electrolyte composition of intracellular fluid?
LOW sodium
HIGH potassium
What is the general electrolyte composition of extracellular fluid?
HIGH sodium
LOW potassium
What electrolyte determines hydration status?
Total body sodium
the Na concentration determines IV volume. Water follows sodium
T/F the serum sodium concentration reflect total body water NOT total body sodium content?
True
Water is freely moveable across cell membranes and sodium is not. Therefore, if you see high Na on bloodwork, this means there is LOW body water (dehydration), does NOT tell you that there is too much sodium.
If you see low Na on bloodwork, it can be a relative excess of water and not truly a hyponatremia.
You have a patient that presented for anorexia. You run a CBC/Chem and see hyponatremia. How would you interpret this?
Releative water excess.
This patient is losing water and sodium through normal losses, but continuing to drink W/O replacing the sodium via food. This is causing water excess and making it appear that there is no sodium.
You run a CBC/Chem that presented with polyuria. The results show a hypernatremia. What do you interpret from this?
There is a water deficit.
What would be the outcome of a patient losing the following fluid types:
-Hypotonic
-Hypertonic
-Isotonic
-Hypotonic- Losing more water than solute could lead to hypernatremia
-Hypertonic: losing more solute than water could lead to hyponatremia
-Isotonic: unchanges Na
What is the difference between dehydration and hypovolemia?
Dehydration is loss of fluid from the interstitial space. This occurs slowly over days-weeks and should/can be replaced slowly.
Hypovolemia is loss of fluid from the intravascular space and occurs much more rapidly, requiring a rapid restoration of blood volume.
T/F the replacement fluid type for dehydration and hypovolemia is the same
True
High in NA, low in K
What are indications to give a patient fluids?
1) dehydration
2) hypovolemia
3) Anorexia (<12-24 hr and expected to stay that way)
4) severe losses
5) general anesthesia
6) As a vehicle for other stuff like drugs
What is the biggest difference between crystalloids and collids?
Crystalloids are essentially just salt water which gives them the ability to freely move within the extracellular space and redistribute into the interstitium rapidly. You can very safely give a large amount at a quicker rate.
Colloids contain molecules taht do not leave the intravascular space, and thus they will stay in teh IV space longer
What are the 4 downsides to using colloids?
1) potential for interstitial leak and edema formation
2) changes coagulation (dec vWF, platelet aggregation and fibrin clot stability)
3) Kidney injury
4) Cost
What are 4 examples of ISOTONIC fluids (fluids that have similar tonicity to the ECF)
1) LRS
2) Normal Saline ().9% NaCl)
3) Normosol R
4) Plasmalyte A/148