[good_boy_1234]

I read in kaplan that Hypokalemia & Hypercalcemia cause NDI...
May anyone explain how ?

 

[DRFP]

I read in kaplan that Hypokalemia & Hypercalcemia cause NDI...
May anyone explain how ?

? How can they cause anything?
Are not electrolytes a sign of a disease, caused by a condition, in other words other problems cause the electrolyte imbalance.

Deficient of an electrolyte or excess in all cases I can think of is a syndrome or injury which is something else then just low K or high Ca++

I too would like to know

 

[khanar]

Yes, Kaplan is right

Indeed hypercalcemia and hypokalemia are causes of NDI.
Hypercalcemia:
Nephrogenic diabetes insipidus occurs from medullary calcium deposition and inhibition of aquaporin-2, the arginine-vasopressin-regulated water channel.
Hypokalemia:
I don't know why but I guess it has something to do with the osmosis generated by hypokalemia making ADH ineffective at the tubular level.

 

[DRFP]

Indeed hypercalcemia and hypokalemia are causes of NDI.
Hypercalcemia:
Nephrogenic diabetes insipidus occurs from medullary calcium deposition and inhibition of aquaporin-2, the arginine-vasopressin-regulated water channel.
Hypokalemia:
I don't know why but I guess it has something to do with the osmosis generated by hypokalemia making ADH ineffective at the tubular level.

But this is chicken and Egg thing, you just don't have hyperCalcemia by itself without a condition that causes it.............if not then tell me how?

Thats my dilemma

its usually three steps

Marfans = fibrillin problem = Aorta weakened

not just: problem with fibrillin = Aorta weakened

Do you see how I'm thinking? Thats why I question the simplicity of it, something causes the condition to exist.

 

[khanar]

This is not the point

But this is chicken and Egg thing, you just don't have hyperCalcemia by itself without a condition that causes it.............if not then tell me how?

Thats my dilemma

Am not arguing your point.
Electrolyte abnormalities are of course manifestations of primary illnesses but at the same time they themselves can result in diseases.
For example a child is having diarrhea which resulted in hyponatremia. This hyponatremia in turn resulted in irritability and seizures. In such a case you cannot say that the diarrhea resulted in seizures

 

[khanar]

But this is chicken and Egg thing, you just don't have hyperCalcemia by itself without a condition that causes it.............if not then tell me how?

Thats my dilemma

its usually three steps

Marfans = fibrillin problem = Aorta weakened

not just: problem with fibrillin = Aorta weakened

Do you see how I'm thinking? Thats why I question the simplicity of it, something causes the condition to exist.

So your post is now different from what I initially replied to (see my last post)

 

[DRFP]

So your post is now different from what I initially replied to (see my last post)

Actually it looks like we agree :happy:

 

[good_boy_1234]

Thank you Talib....I am persuaded about Hypercalcemia machanism
But we still need to know about hypokalemia..I hope someone will give us the answer!

 

[DRFP]

Thank you Talib....I am persuaded about Hypercalcemia machanism
But we still need to know about hypokalemia..I hope someone will give us the answer!

Directly from Kaplan IM CK 2008-09

OK secondary is what I was saying, you are looking for the differentials for Hyper Calcemia, HypoKalemia, there will be another condition in which DI is seen as well........that is what I said, do not make this more complicated then it should be

 

[good_boy_1234]

Oh man...I read it from Kaplan, but there must be an explanation.
Not just saying it is secondary to.....

 

[DRFP]

Oh man...I read it from Kaplan, but there must be an explanation.
Not just saying it is secondary to.....

LOL that is cut and pasted From Kaplan 2009, friend it clearly says Secondary!

Don't get hung up on this, yes there are reasons many for the conditions that is the difference to secondary and primary, secondary means that its not primary caused by the electrolyte imbalances

Understand, an electrolyte imbalance is caused by something, you just do not have low K+. Your body does not Make Ca++ and K+ and such, it is absorbed and excreated, so some mechanism or process causes the electrolyte imbalance and then the imbalance causes other problems like DI.............. Do you see? You are asking for pages and pages of possible explanations for the electrolyte imbalance and that has been my point.

The step exams are more Concepts then getting it 100% correct and exact. You see we can say that XYZ condition can cause this but if there are many possible causes, then the exam can ask any of those possible causes that lead to this condition. Have you ever listened to Goljan? He explains this in detail.

Understand mechanisms and you have part of the way to think for this exam.

 

[drmodi44]

Acute hypercalcemia induces natriuresis (nephrogenic diabetes insipidus) and polyuria, possibly resulting in extracellular fluid contraction and dehydration.

Chronic hypercalcemia can reduce renal concentrating ability, further exacerbating polyuria and polydipsia. The disorder also causes urinary stones, nephrocalcinosis, and chronic renal failure.

have a look at this site...

http://emedicine.medscape.com/article/117648-overview

 

[good_boy_1234]

DRFP , I do not think so!!
Idiopathic which is the primary means that there is no known cause, not it is not caused by electrolyte disturbances!!
But when it is secondary there must be a mechanism...why that cause is responsible for phenomenon.
It is like HTN man!
Like Hypercalcemia...Talib explained it
we will wait if somebody has an answer...

 

[drmodi44]

reason behind prolonged hypercalcemia causing DI is Renal failure....kidney loosing its ability to concentrate urine....just remember this simple concept....
no need to go in much detail...

 

[DRFP]

DRFP , I do not think so!!
Idiopathic which is the primary means that there is no known cause, not it is not caused by electrolyte disturbances!!
But when it is secondary there must be a mechanism...why that cause is responsible for phenomenon.
It is like HTN man!
Like Hypercalcemia...Talib explained it
we will wait if somebody has an answer...

LOL Idiopathic means we do not know the cause then.........and thats the answer, there is no answer.

thats my point. Its important to understand diseases and concepts more then anything.

Discussion is good to a point. I think you wanting an exact answer is a waste of time, it won't help you.

Lets take HTN,

Sodium for instance, High sodium can cause HTN true, yet what causes the High sodium? You just do not have high sodium idopathically, at least until you rule out several things usually
Renal
Adrenal
DI
for HTN.

High sodium can also be caused by Dehydration
Malignancy could too

I'm sure I'm missing other sources because this is quickly off the top of my head,

BTW Hypocalcemia and HyerKalemia are both Electrolytes........... What else do you think they are?
Potassium and Calcium are both minerals and inorganic ( hence the body cannot produce them), I'm confused a little by your response.

 

[DRFP]

The only thing we left off is lithium can cause Hyperkalemia and Hyponatremia so it can cause DI

Oh Legionella can cause Hyponatremia as well

 

[convalescence]

to everyone above

i dont understand what you guys are arguing about?

everyone please thank me for this post.