Flashcards in Kidney-ADH dx and electrolytes Deck (21):
What type of urine and blood osmolality do you see with SIADH?
urine osmolality>blood osmolality
crazy conc'n urine, dilute blood.
What is SIADH a common cause of?
b/c body compensates by decreasing aldosterone secretion
What can be the result of the hyponatremia seen in SIADH? How should this be corrected?
cerebral edema and seizures
correct slowly b/c low-->high the pons will die.
Central pontine myelinolysis (demyelination syndrome)-->locked in syndrome.
What are some common causes of SIADH?
LUNG AND BRAIN
Ectopic ADH via small cell lung cancer
CNS disorders/head trauma
What is the treatment for SIADH?
IV hypertonic saline
demeclocycline (ADH antagonist)
What are some causes of central diabetes insipidus?
lack of ADH release from hypothalamus
What are some causes of nephrogenic diabetes insipidus?
kidney resistant to ADH
hereditary or secondary to hypercalcemia
demeclocycline use (ADH antagonist)
How do you diagnose central DI v. nephrogenic DI?
see dilute urine and conc'n blood.
do water deprivation test. and still see dilute urine (2-3 hrs)
give vasopressin analog. Works-central. Doesn't work-nephrogenic
What is the treatment for central DI?
What is the treatment for nephrogenic DI?
HCTZ (thiazide diuretics cause dehydration and prompt PCT to absorb more water)
Indomethacin (decreases GFR via afferent arteriole constriction)
Amiloride (inhibits the CT sodium channels that take up Lithium and allow it to inhibit ADH receptors).
Causes of hyperkalemia?
lysis of cells
high blood Sugar (insulin insensitivity)
**also ACE inhibitors, potassium sparing diuretics
What can cause hypokalemia?
Insulin (when correcting hyperkalemia give w/ IV dextrose)
beta agonist (albuterol)
thiazide and loop diuretics
What happens when sodium gets too low or too high?
CNS effects stupor, coma. Seizures w/ hyponatremia.
What are 6 causes of hypernatremia?
dx of kidney
What do you see with hypokalemia?
flattened t waves
arrhythmias: increased QT interval, torsades de point
What do you see with hyperkalemia?
tented (peaked) t waves. Arrhythmias, Wide QRS like vtach.
When potassium is low, what might else be low?
Symptoms of low Ca++?
tetany: check Trosseau and Chvostek
Symptoms of high Ca++?
Groans (abdominal pain)
Thrones (increase in urinary frequency)
psychiatric overtones (delirium, altered mental status)
Low Magnesium causes what?
torsades de point