Between the ISF and the ICF, ____ is the main determinant of extracellular osmotic pressure
Na+
Between the ISF and the ICF, ____ is the main determinant of intracellular osmotic pressure
K+
What is hematocrit?
What are some ways that we can assess fluid volume status?
Why are maintenance fluids given?
To replace insensible losses
What is the formula for maintenance fluids?
4-2-1 Rule!
How to calculate fluid deficit
(Maintenance rate) x (number of hours NPO)
Replacement strategy for fluid deficit
Replace over 3 hours
When should we begin fluid deficit replacement?
ASAP! Start fluids in the holding area. Want to make sure they aren’t totally dry on induction.
A soaked 4x4 holds _____cc of blood
10cc
A soaked lap sponge (lap tape) holds ___cc of blood
100-150 cc (soaked an dripping)
We tend to (over/under)estimate the amount of blood loss
Underestimate
Calculations for estimated blood volume (EBV)
Neonates
Adults
Calculating ABL
Fluid loss due to third spacing may be caused by
Surgeries and their expected evaporative/3rd space loss
D5W has an osmolarity of
253
(these are called maintenance fluids)
Isotonic solutions have an osmolarity of
300
(these are called replacement fluids)
Examples of isotonic solutions
Examples of hypertonic solutions and their osmolarities
Advantages and disadvantages of crystalloids
Advantages:
Disadvantages:
LR provides ____cc of free water per liter of fluid
100cc
This tends to lower Na+
LR
It is made of normal saline with additives:
Normal Saline
Electrolytes: