Na+ Flashcards
Would how would Na+ levels change in pts taking large amounts of diuretics w/o drinking water? What would the volume status be?
Hypovolemic hyponatremia
The daily solute load is generally ___-___ mmol/day.
600-1200
Tx for hypervolemic hypernatremia?
Why don’t you want to correct it too fast?
- Can be problematic. If severe, it may require both water administration plus either diuretics or dialysis to remove the excess sodium.
- Rate of correction should not exceed 0.5 mEq/L/hr, as too rapid a reduction in serum sodium and osmolality may result in shift of water into the brain and brain edema.
What are some examples of scenarios that cause hypervolemic hypernatremia?
Hypertonic fluid administration
Mineralocorticoid excess states
Salt poisoning (and seawater ingestion)
If you decrease your daily excretion of solute by 2/3s, how does your daily urine volume change?
Also decreases by 2/3s (e.g. Beer Drinker’s Syndrome)
In hyponatremia, what’s an eg of a scenario where there is decreased filtration of solute by the glomeruli?
Renal failure
Name some edematous disorder examples.
Congestive heart failure (CHF), liver cirrhosis, renal failure
What are some examples of scenarios that cause hypervolemic hyponatremia?
CHF
Liver cirrhosis
Renal failure
Would how would Na+ levels change in pts administered a large amount of hypertonic saline? What would the volume status be?
Hypervolemic hypernatremia
What is the “normal” urine osmolality and urine output per day? (some ADH present, not too much or too little)
Urine osmolality ~= 400 mmol/kg
Urine volume ~= 1.5 L/day
*Calculations assume that there is excretion of 600 mmol of solute per day
What is the tx for euvolemic hyponatremia?
- Mild?
- *More severe?
- Symptomatic?
- Mild asymptomatic hyponatremia should be considered a diagnostic clue but does not mandate treatment.
- More severe asymptomatic hyponatremia (i.e., serum sodium < 125 mmol/L) should be treated with water restriction.
- Symptomatic hyponatremia (confusion, seizures, coma due to hyponatremia) is considered a medical emergency and generally requires hypertonic saline with or without diuretics. Avoid rapid or overcorrection!
What is the TBNa+ in pts w/hypo-, eu-, and hypervolemic hypernatremias?
- Hypo: Low TBNa+
- Eu: normal TBNa+
- Hyper: High TBNa+
When evaluating urine Na+ in hyponatremia, what does normal UNa+ (> 20 mmol/L) suggest?
Suggests renal loss of Na+ or excess ADH in the absence of renal sodium avidity, as in SIADH.
What is the tx for hypovolemic hyponatremia?
Hypervolemic hyponatremia?
hypovolemic hyponatremia = nl (isotonic) saline
Hypervolemic hyponatremia = fluid restriction + diuretics
If a person drinks gallon’s of beer without food, why can’t the kidney just get rid of this extra fluid?
Because the kidney needs solute to be able to excrete the fluid (water follows salt)