Hyponatriuria in CHF?

[Kahldrogo]

How can we explain the presence of hyponatriuria in patient with cronich heart failure since, in this case, there usually is hyponatriemia? The question is: how can these two be compatible with each other? I know there is an RAA and ADH activation but I used to think the ADH system activation was more powerfull and this led to hyponatriemia. Unluckily, this collide with the finding of hyponatriuria. What am I missing?

---

Members don't see this ad.

 

[Pr1d3D0c]

How can we explain the presence of hyponatriuria in patient with cronich heart failure since, in this case, there usually is hyponatriemia? The question is: how can these two be compatible with each other? I know there is an RAA and ADH activation but I used to think the ADH system activation was more powerfull and this led to hyponatriemia. Unluckily, this collide with the finding of hyponatriuria. What am I missing?

Don't quote me here, but I think it has to do with concentrations for one thing. If you activate RAAS, then you are taking up sodium preferentially for sure, reducing the sodium content of urine. However, because of profound activation of ADH, you have hyponatremia (excess water will dilute the excess salt taken up to such a degree that patient is hyponatremic). However, this matters little when discussing sodium concentration in urine, if you're taking most of it up, then patient will also be hyponatriuric I would think.

 

[Psai]

If your blood salt is low and you are excreting salt from the blood, your urine salt may be low

 

[jdh71]

How can we explain the presence of hyponatriuria in patient with cronich heart failure since, in this case, there usually is hyponatriemia? The question is: how can these two be compatible with each other? I know there is an RAA and ADH activation but I used to think the ADH system activation was more powerfull and this led to hyponatriemia. Unluckily, this collide with the finding of hyponatriuria. What am I missing?

How do the two collide and therefore cannot explain hyponatremia ?

 

[intubesteak]

RAAS is activated, kidneys resorb salt and water--proportionally, more water than salt. So you may have hyponatremia but it is only because you have absorbed more water proportionally. Total body sodium is increased.