test 4 Flashcards
kidney function is indicated by the
GFR (glomerular filtration rate)
The kidneys of children reach adult GFR at approximately
1 year of age, but measured GFR vary by age book says 2 years
GFR can be estimated (eGFR) with what equation
schwartz equation
eGFR mL/minute/1.73m2 = (k) (height)/serum creatinine
k = constant of 0.413 for all ages/genders
height is measured in cm
serum creatinine is measured in mg/dL
renal blood flow is dependent on
intravascular volume and adequate cardiac output with oxygenated blood
equation used to determine whether kidney dysfunction is only a result of hypoperfusion to kidney
fractional excretion of sodium
normal BUN-to-creatinine ratio
10:1 to 20:1
Elevated BUN-to-creatinine ratios are associated with
shock or dehydration with acute kidney failure
can also be from nephrolithiasis or gastrointestinal or pulmonary hemorrhage
Low BUN-to-creatinine ratios are associated with
rhabdomyolysis, syndrome of inappropriate antidiuretic hormone secretion, lung disease, malignancy, low dietary protein intake or certain medications
an abrupt cessation or significant decline in the kidneys ability to eliminate waste products, regulate acid-base balance and regulate electrolyte balance
Acute renal failure
resorption of electrolytes occurs predominantly where
the proximal convoluted tubule
renal wasting of sodium can be due to
pseudohypoaldosteronism following a chronic tubular injury (bilat hydronephrosis), true hypoaldosteronism (congenital adrenal hyperplasia) or excessive diuretic use.
acidosis increases serum
potassium as hydrogen ion displaces potassium from the intracellular compartment and alkalosis is associated with decreases in serum potassium with reversed cation movement
under hyperkalemic conditions, _____ is secreted and ____ is eliminated by the kidney
aldosterone is secreted
potassium is eliminated
tubular reuptake of potassium occurs in the
proximal tubule and the thick ascending loop of henle
medications associated with magnesium wasting are associated with
natriuresis and/or general tubular epithelial cell damage:
loop and thiazide diuretics, calcineurin inhibitors, cisplatin, ifosfamide, amphotericin B and aminoglycosides
transient wasting of _____ can occur following recover from AKI
magnesium
_____ has been associated with hypokalemia due to kaliuresis
hypomagnesemia
Development of nephrogenic structures begins
3rd-5th week of gestation
Development of nephrogenic structures requires angiotensin II. What maternal medication can cause harm to this process
Ace inhibitors can result in fatal renal dysplasia
Fetal kidneys require only ____ of cardiac output
10%
At birth, cardiac output _____ and renal vascular resistance ______
increases
decreases
increase in GFR and renal blood flow
Renal blood flow is dependent on
intravascular volume and sufficient cardiac output
collection of epithelial cells within the distal convoluted tubule that (in conjunction with arterioles) senses the Na levels
Juxtaglomerular apparatus (JGA)
renal response to Decreased renal blood flow
renin secretion which increases reabsorb of NA which increases intravascular volume