Drugs for Hypo/Hypernatremia Flashcards
how do content and concentration of sodium differ in reference and meaning
concentration cares about sodium relative to water regardless of what the amount is.
what is the equation for for plasma osmolality
2(Na) + Glucose/18 + BUN/2.8
What is the effect of .9 NaCl on ICF and ECF volume
increases ECF volume
What is the effect of .45 NaCl on ICF and ECF volume
Increases both ICF and ECF volume with majority of expansion in ECF
What is the effect of 3 or 5% NaCl solution on ICF and ECF
Expand ECF
Shrink ICF
What is the effect of 5% dextrose
increases total body water.
What value constitutes hypernatremia
> 145 mEq/L
What value constitutes hyponatremia
<135 mEq/L
what is normal serum osmolality
285-295 mOsm/kg
What is the mnemonic of hyponatremia symptoms
SALT LOSS
Stupor/coma
Anorexia, N/V
Lethargy
Tendon reflexes decreased
Limp muscles
Orthostatic hypotension
Seizures/headache
Stomach Cramping
what must be avoided when treating a sodium imbalance
overly rapid correction can cause osmotic demyelination syndrome
if you have acute symptomatic hyponatremia, what is the limit of rise?
can use 2.5 mEq/L/hr
not to exceed 20 mEq/L/day
If you have chronic symptomatic hyponatremia, what is the limit of rise
.5 mEq/L/h until 120 mEq/L not to exceed 8-12 mEq/L/day and no more than 18 mEq/L in first 48 hrs
What is the MOA of conivaptan
blocks Vasopressin receptor (ADH) which promotes excretion of water
What are the clinical applications and toxicities of conivaptan (IV)
treats euvolemic and hypervolemic hyponatremia in people who are hospitalized and not responsive to fluid restriction.
Can cause orthostatic hypotension, fatigue, thirst, polyuria
