Hyperkalemia Article Flashcards
Extracellular K level
4.0 - 4.5 mEq/L
Total body K is regulated by
the kidneys
Increasing the extracellular K concerntration results in
Early effects of hyperkalemia
increase myocyte excitability by shifting the resting membrane potential to a less negative value and thus closer to threshold
When moderate hyperkalemia occurs
myocyte depression occurs
At what mV dose calcium channels open
-40 to -45 mV during phase 0
The phase 2 plateau is cause by what
the movement of K out of the cell and Ca into the cell. temporarily off setting eachother, hence the plateau
During phase 3 what happens
the Ca channels close and the K channels continue to release K out of the cell. Hence the doward slope of the the curve to a more negative state.
Signs seen on an EKG of hyperkalemia
ST segment depression
Peaked T waves
shortening of the QT interval
Earliest sign of hyperkalemia on the EKG
Peaked T waves
Peaked T waves
K greater then 5.5 mEq/L
Only shows on 22% EKGs
K greater then 6.5 mEq/L
widening QRS complex and prolonged PR interval
8-9 mEq/L
SA node may stimulate the ventricles without atrial activity
10 mEq/L
SA node conduction no longer occurs
Junctional pacer takes over causeing accelerated junctional rhythm
> 10 mEq/L
widening of the QRS to become a sine wave and blends with the T wave.
U FUCKED Vfib and Asystole
3 Ways to Treat Hyperkalemia
Membrane stabilization
Promote k influx into the Cell
Promote K Removal from the body
Initial Tx for hyperkalemia
Ca infusion to antagonize the effects of hyperkalemia at the cellular level
Changes the resting membrane potential to less negative decreasing the excitability of the cell
Ca effect can be seen how quickly
1-3 min
Ca effects las how long
30-60 min
which is the prefered calcium of choice IV gluconate or chloride
gluconate
10% solution given 10ml
or
100 mg
calcium chloride is how many times stonger then calcuim gluconate
3X
Typically how do you promote K influx into the cell
D50 and Insulin
effects are seen within 10 - 20 min
Decreases the K by 0.6 - 1 mEq/L
The quickest K removal is done how
dialysis
not the most fesible though
Other ways to get K out of the Body
Ion exchange resin with sorbitol via the gut, orally or rectally
decreases the K by 1 mEq/L in 24 hours
