00:01
Our last category is
Hypervolemic Hypotonic Hyponatremia.
00:05
This occurs when we have
total body volume excess
or ECV excess,
but the actual effect of
arterial blood volume
on what circulating is
on the low side.
00:15
Those included
edematus states like:
heart failure, liver cirrhosis,
and nephrotic syndrome.
00:21
Here in this situation,
ADH is appropriately activated
because we have
a low effective circulating volume.
00:29
The urine osmol is
going to be high.
00:31
Why? Because ADH
is present and active.
00:33
So it's going to be able to
concentrate the urine.
00:36
The urine sodium in the situation
will be low,
typically less than 20 meq/L.
00:43
And that makes sense,
because think about
what the body is trying to do.
00:45
It wants to maximally
conserve volume,
therefore, RAAS,
Renin-Angio-Aldo-System
is going to be activated.
00:52
And sodium will be reabsorbed
at that proximal tubule
as well as the principal cell.
00:58
We can also see
hypervolemic, hypotonic,
hyponatremia
in situations like
advanced renal failure.
01:05
That's due to an
impaired free water excretion
or delusional hyponatremia.
01:10
The effect of plasma osmolality
is low,
but remember the measured
plasma osmolality may be high
and that's due
to the contribution of urea,
which is an ineffective osmole and
accumulates in renal failure.