How can you tell the difference between SIADH and cerebral salt wasting?
Both conditions are characterized by hyponatremia with elevated urine sodium, concentrated urine, and no edema. The key distinguishing factor is that in cerebral salt wasting the patient is hypovolemic versus in SIADH the patient is euvolemic to hypervolemic.
How is CSW different from SIADH?
Uric acid levels are low in both SIADH and CSW. In SIADH, a low serum uric acid level is ascribed to volume expansion. In CSW, the same finding is ascribed to impaired sodium reabsorption by the proximal tubule.
What is cerebral salt wasting?
Cerebral salt wasting syndrome (CSW) is defined as a renal loss of sodium during intracranial disease leading to hyponatremia and a decrease in extracellular fluid volume. The pathogenesis of this disorder is still not completely understood.
What is the difference between hyponatremia and SIADH?
In SIADH, hyponatremia is caused by water retention due to inappropriate secretion of antidiuretic hormone (ADH) (10-15). But in CSWS, hyponatremia is associated with high urine output, high urine sodium concentration, and plasma volume depletion (16).
Is it cerebral or renal salt-wasting?
Cerebral salt-wasting (CSW), or renal salt-wasting (RSW), has evolved from a misrepresentation of the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) to acceptance as a distinct entity.
How is urine sodium measured?
There are two types of sodium urine test. A random test looks at sodium in a single urine sample. A 24-hour test looks at urine sodium over the course of a 24-hour period.
Why does cerebral salt wasting happen?
The exact mechanism underlying cerebral salt-wasting syndrome remains unclear. In the setting of cerebral injury, one hypothesis is that an exaggerated renal pressure–natriuresis response caused by increased activity of the sympathetic nervous system and dopamine release is responsible for urinary sodium loss.
Is it cerebral or renal salt wasting?
Why does cerebral salt wasting occur?
What type of hyponatremia is in SIADH?
In persons with SIADH, the nonphysiological secretion of AVP results in enhanced water reabsorption, leading to dilutional hyponatremia. While a large fraction of this water is intracellular, the extracellular fraction causes volume expansion.
What is the difference between SIADH and salt wasting?
In cerebral salt wasting, sodium urine concentration is lower than 100 meq/liters while SIADH has a greater value. Treatment of SIADH is by fluid restriction, intravenous saline, and certain medications. Treatment of cerebral salt wasting is through frequent hydration to prevent dehydration plus medications.
What is the difference between SIADH and CSWS?
CSWS is usually associated with hypovolemia whereas patients with SIADH are euvolemic. In addition, patients with SIADH exhibit elevated ADH levels and rarely develop urine sodium levels > 100 mEq/L. Patients with CSWS usually have normal ADH levels and often develop urine sodium levels > 100 mEq/L.
How do you treat SIADH and cerebral salt wasting?
Treatment of SIADH is by fluid restriction, intravenous saline, and certain medications. Treatment of cerebral salt wasting is through frequent hydration to prevent dehydration plus medications.
What is the role of saline in the treatment of SIADH?
Infusion of isotonic saline in the case of SIADH will worsen hyponatremia, since it will trigger increased sodium excretion, with some retention of free water, and thus continued hyponatremia. It must be noted that SIADH and CSW may coexist within a single patient, complicating treatment strategy.