Fluid and electrolyte balance and disturbances Flashcards
K+ is the major determinant what r/t cell excitability
RMP
Ca++ is the major determinant of what r/t cell excitability
threshold potential
Normal Ionic balance:
what is the normal rmp? and what controls it
-90
K+
Normal Ionic balance:
what is the normal threshold? and what controls it
-60
Ca++
point to the RMP
Normal Ionic balance:
clearify
Muscle rmp is -90
Nerve is -70
just so i dont get confused
Normal Ionic balance:
point to the Threshold line
Normal Ionic balance:
what one is HYPOkalemia
Normal Ionic balance:
explain how you know it is hypokalemia and what it all means.
- RMP HYPERpolarized (more negative)
- making it LESS excitable
- Moves away from threshold
- More of a stimulus if needed to exert an action
Normal Ionic balance:
Point to HYPERkalemia
Normal Ionic balance:
explain how you know it is hyperkalemia and what it all means.
- HYPOpolarized (less negative/closer to 0)
- RMP moves closer the threshold
- MORE excitable
- Less of a stimulus is needed to evoke a response
Normal Ionic balance:
what the hell can cause D? and what is going on?
- the RMP has past the threshold
- Cardioplegia solution
- Hyperkalemia
- Na+ channel snaps open
- causes absolut refractory period b/c Na+ channels can’t fire
- K+ levles = 15-40 mEq
Normal Ionic balance:
point to Hyper calcemia
Normal Ionic balance:
explain how you know it is hypercalemia and what it all means.
- Threshold is hypopolarzed
- moves closer to 0
- Decreased excitability
- bigger gap b/t rmp and threshold
- More stimulus is needed to elict a response
Normal Ionic balance:
what the hell if F showing?
- hyperkalemia treated with Ca++
- the RMP is hypopolarized (hyperkalemia)
- the threshold is increased to decrease the excitability
- threshold increased
Normal Ionic balance:
what is G showing explain how you know and what it all means.
- first a nerve cell b/c it says so and the RMP is at -70 (normal for nerve cell)
- hypocalcemia is shown
- threshold is decreased
- Increased excitability
- smaller gap between RMP and Threshold
- Smaller stimulus will be neede to elict a response
can s/s of hypocalcemia be elicited when the pt is hyperventilated?
yes, hyperventilation can cause resp alkolosis. ionzied Ca++ decreases
therapies and mechanisms for treating HYPERkalemia:
what is the fastest treatment, but does not correct the hyperkalemia
Give Ca++
therapies and mechanisms for treating HYPERkalemia:
why administer HCO3-
H+ concentraions in the plasma decrease and metabolic alkolosis ensues.
H+ shifts out of cell to to buffer the alkolosis and in exchane K+ shfts into the cell
therapies and mechanisms for treating HYPERkalemia:
what does hyperventilation do?
H+ concentration in plasma decreases causing resp alkolosis occurs.
H+ shifts out of the cell to buffer the alkolosis and in exchange K+ shifts into the cell
for each 10mmHg decrease in PaCO2 serum K+ decreaseshow much?
0.5 mEq/L
therapies and mechanisms for treating HYPERkalemia:
what does giving insulin-glucose do?
insulin stimulates Na+K+ pump, drives K+ into the cells
Insulin also opens glucose channels
Glucose is administered along with insulin to prevent hypogylcemia
therapies and mechanisms for treating HYPERkalemia:
what do Beta-2 agonist do?
stimulates Na+K+ pump, drives K+ into the cells
insulin stimulates Na+K+ pump, drives K+ into the cells
2 additional treatments
kayexalate
Dialysis
