1/
I feel comfortable with hyponatremia?
I feel comfortable with hyponatremia?
2/
You are on medicine consult and you know what is about to happen
Page: "Ms. S - Consult for hyponatremia."
You are on medicine consult and you know what is about to happen
Page: "Ms. S - Consult for hyponatremia."
3/
The approach for hyponatremia history and physical exam should center on the ...
The approach for hyponatremia history and physical exam should center on the ...
4/
I feel confident in distinguishing euvolemia from hypovolemia
I feel confident in distinguishing euvolemia from hypovolemia
5/
I don't think we can accurately distinguish euvolemia from hypovolemia from subtle hypervolemia. Why anchor your ddx in subjective exam as opposed to objective lab? Of course you should perform an exam but it should not be the center of gravity in working up hypoNa.
I don't think we can accurately distinguish euvolemia from hypovolemia from subtle hypervolemia. Why anchor your ddx in subjective exam as opposed to objective lab? Of course you should perform an exam but it should not be the center of gravity in working up hypoNa.
6/ Pearl Alert
Always ask what is the glucose when thinking about hypoNa! Because cells care more about tonicity than Na.
Low K or Ca ... what is Mg
Low Na ... what is Glu
Always ask what is the glucose when thinking about hypoNa! Because cells care more about tonicity than Na.
Low K or Ca ... what is Mg
Low Na ... what is Glu
7/ Back to case
Ms. S glu is normal. Na 126. sOsm 263.
Ms. S glu is normal. Na 126. sOsm 263.
8/
In ideal world, if the kidney only cared about Na (osmolality), what would you expect the urine concentration to be?
In ideal world, if the kidney only cared about Na (osmolality), what would you expect the urine concentration to be?
9/
If the stimulus for low Na was drinking too much water, then urine osmolality should be low. However, this is usually NOT the case.
If the stimulus for low Na was drinking too much water, then urine osmolality should be low. However, this is usually NOT the case.
10/ Physiology Alert
The body cares more about volume than Na.
Why? BP = CO x SVR; CO = HR x Stroke VOLUME
The brain and all tissues need perfused. Therefore, Na is often low in cases of low volume b/c body trying to retain every drop of fluid filtered through kidney.
The body cares more about volume than Na.
Why? BP = CO x SVR; CO = HR x Stroke VOLUME
The brain and all tissues need perfused. Therefore, Na is often low in cases of low volume b/c body trying to retain every drop of fluid filtered through kidney.
11/
Ms. S urinalysis shows a specific gravity of 1.02.
Which diagnoses can be excluded?
Ms. S urinalysis shows a specific gravity of 1.02.
Which diagnoses can be excluded?
12/
Only 2 causes of dilute urine (SG 1.005). One occurs in context of excessive water intake. The other in patients w/ low solute intake who cannot concentrate urine aka beer potomania not PROTomania. You can tell protein was on my mind before @dminter89 corrected me.
Only 2 causes of dilute urine (SG 1.005). One occurs in context of excessive water intake. The other in patients w/ low solute intake who cannot concentrate urine aka beer potomania not PROTomania. You can tell protein was on my mind before @dminter89 corrected me.
13/
Ms. S urine osmolality was elevated as predicted by the last 2 digits of SG (1.020 -> 20 x 30 = 600). Is my math right @rabihmgeha? I know you are praying it is not right but I used a calculator HAHAHA
Ms. S urine osmolality was elevated as predicted by the last 2 digits of SG (1.020 -> 20 x 30 = 600). Is my math right @rabihmgeha? I know you are praying it is not right but I used a calculator HAHAHA
14/
Now it is time to use volume exam, urine sodium and serum uric acid.
If blood volume is low, the kidney will do everything to hold on to Na (b/c water follows) therefore low urine sodium. Otherwise, urine Na elevated.
But be cautious b/c can have more than one process.
Now it is time to use volume exam, urine sodium and serum uric acid.
If blood volume is low, the kidney will do everything to hold on to Na (b/c water follows) therefore low urine sodium. Otherwise, urine Na elevated.
But be cautious b/c can have more than one process.
15/
Ms. S urine Na elevated and serum uric acid low.
What does Ms. S have? To summarize, low serum Osm, high urine OSM, high urine Na, and low serum uric acid?
Ms. S urine Na elevated and serum uric acid low.
What does Ms. S have? To summarize, low serum Osm, high urine OSM, high urine Na, and low serum uric acid?
16/
The low serum uric acid prioritizes SIADH. I am not sure what serum uric acid is in AI and low T4/3. Hoping medtwitter helps me learn.
The low serum uric acid prioritizes SIADH. I am not sure what serum uric acid is in AI and low T4/3. Hoping medtwitter helps me learn.
17/
The low serum uric acid in SIADH I believe is due to slight hypervolemia from ADH leading to increased uric acid filtered and thus excreted. Please correct me if I am wrong. If this is true, what would we expect to happen to serum uric acid in adrenal insufficiency?
The low serum uric acid in SIADH I believe is due to slight hypervolemia from ADH leading to increased uric acid filtered and thus excreted. Please correct me if I am wrong. If this is true, what would we expect to happen to serum uric acid in adrenal insufficiency?
18/
I don't know the answer. Teach me.
I don't know the answer. Teach me.
19/
Ms. S ultimately diagnosed w/ SIADH from anti-psychotic medication. If you want to thread on treatment, let us (@rabihmgeha) know
Ms. S ultimately diagnosed w/ SIADH from anti-psychotic medication. If you want to thread on treatment, let us (@rabihmgeha) know
20/
I feel more comfortable with approaching hyponatremia?
I feel more comfortable with approaching hyponatremia?
21/
ps: be very cautious that your patient does not have ATN or CKD before using urine Na. You cannot confidently diagnose SIADH in such cases. Though ultimately you can still treat appropriately.
ps: be very cautious that your patient does not have ATN or CKD before using urine Na. You cannot confidently diagnose SIADH in such cases. Though ultimately you can still treat appropriately.
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