1 cause of hypernatremia i.e neurosurgery ICU ?
In DI there’s loss of excess water in urine which start increasing serum Na+ . As serum Na+ reaches upper limit of normal (145) : thirst centre gets activated (in most of the DI patients thirst centre is normal) which PREVENT further increase in Na+ . Marked hypernatremia can be seen in DI if there’s damage to Thirst centre also . But dilutional hyponatremia Can NEVER be seen in DI ; it can only be seen in SIADH .