Flashcards in Renal Deck (197)
What are the side effects of lasix therapy?
What considerations for ototoxicity need to be considered when giving lasix therapy?
- limit high peak doses
- do not administer with concurrent use with other ototoxic drugs (ex: aminoglycosides)
What considerations for nephrocalcinosis need to be considered when giving lasix therapy?
1) renal calcifications occur in babies after a cumulative dose of 20mg/kg
2) nephrocalcinosis usually resolves in ~ 6 months after d/c lasix use (some ELBW infants will have nephrocalcinosis without a h/o lasix)
What is the major site of action for thiazides?
distal tubule; since only a small amount of Na is absorbed there, diuretic effect is not as effect as with lasix
What is the effect of thiazide therapy on electrolytes?
- preserves Ca (potentiates parathyroid hormone)
- K is lost due to increased urine flow
- Cl is lost following Na and K
What is the effect of thiazide on serum Ca?
- thiazides stimulate PTH secretion and/or potentiate the effect of PTH
- thiazides enhance reabsorption of Ca in the proximal tubule, ascending loop of Henle, distal tubule and collecting ducts
- presence of PTH determines whether or not Ca will be reabsorbed
What is the major site of action for spironolactone?
distal tubule and collecting tubules
What is the mechanism of action for spironolactone?
-inhibits Na reabsorption and therefore inhibits secretion of K
- diuretic effect is not as great as lasix
How is spironolactone used in adjunct with other diuretics to spare K?
- aldactazide (combination of hydrochlorothiazide + spironolactone)
Why is GA a consideration for spironolactone administration?
K losses may not be spared in PT whose distal tubule is hyporesponsive to the effects of aldosterone
What is the effect of ADH in the presence of H2O?
ADH acts on the distal tubule and collecting duct to reabsorb H2O ( allows for the excretion of concentrated urine)
Where is ADH manufactured and stored?
produced by the hypothalamus and stored in the posterior pituitary
What effects do prematurity have on ADH?
PT (and even some FT) are not very sensitive to ADH and will have diuresis; difficulty concentrating urine
What is the cumulative effect of decreased sensitivity to ADH in infants?
at increased risk for hypovolemia and dehydration
What is SIADH?
inappropriate secretion of ADH resulting in dilutional hyponatremia and H2O retention
What can cause SIADH?
1) perinatal asphyxia