09-06-2009, 05:52 PM
why do we have hyponatremia in hepatorenal failure
is it because its precipitated by diuretics or any other reason
is it because its precipitated by diuretics or any other reason
|
to omegamd toha anyone - yazdoc
|
09-06-2009, 07:12 PM
Hepatorenal failure = A syndrome that is characterized by renal failure in a previously fully functional kidney as a result of either Acute (type 1) or chronic (type 2) liver failure. The pathophysiology of exactly how the renal failure results in not known but seems to be related to hypoperfusion of the kidney as a result of increases in portal pressures and reflex vasoconstriction of arteries to the kidneys.
As for the hyponatremia seen in the syndrome it is not a REAL hyponatremia as sodium excretion is actually DECREASED in the urine. the reason we find a LOW sodium CONCENTRATION is due to the effects of VASOPRESSIN. The majority of the cardiovascular volume is "trapped" on the venous side due to portal obstruction/hypertension so the kidneys are underperfused. This activates the renin-angiotensin-aldosterone axis and Vasopressin is released from the hypothalamus. this causes a DILUTION of the body sodium due to the effects of VASOPRESSIN. Remember aldosterone job is to save sodium and by default it save water. Vasopressins job is to save WATER alone and so it dilutes ion concentrations the MOST. |
| « Next Oldest | Next Newest » |