Paulson - Kidneys 101 Flashcards
3 fxns of kidneys
filtration of blood
regulation of blood volume
produce erythropoietin
basic functional unit of kidney
nephron
components of nephron
glomerulus
renal tubule
site of blood filtration
glomerulus
site of water/salts resorption
renal tubule
fxns of proximal convoluted tubule (PCT) (4)
reabsorption of 60% of glomerular filtrate
secretion of large/protein bound drugs/toxins
passive water reabsorption
ammonia production from glutamine
what % of Na, K+, and Ca are reabsorbed in the PCT
65%
what % of phosphate, water, and bicarb are reabsorbed in the PCT
80%
what % of glucose and aa are reabsorbed in the PCT
100%
4 segments of the loop of henle
thin descending limb (DLH)
thin ascending limb (ALH)
medullary thick ascending limb (mTALH)
cortical thick ascending limb (cTALH)
overall fxns of loop of henle (2)
creates a concentration gradient
forms concentrated urine
fxn of distal convoluted tubule
sodium and calcium reabsorption
% of sodium reabsorbed in DCT
5-10%
% of calcium reabsorbed in DCT
10-15%
DCT reabsorption is regulated by (2)
PTH
vit D
fxns of collecting tubule (7)
NaCl reabsorption
bicarb reabsorption
water reabsorption → urine concentration
K+ excretion
H+ excretion
urea excretion
regulation of urine volume
summary of nephron fxn
acute renal fxn (ARF) is same same
acute kidney injury (AKI)
arf is characterized by quickly rising __
and accumulation of __ in blood
BUN/Cr
nitrogenous waste
3 types of causes of arf
prerenal
postrenal
intrarenal
there is no particular race/age more at risk for arf, but 3 rf include
hospitalized
ICU
post general surgery
3 general definitions of ARF/AKI
abrupt (w.in 48 hr) increase in Cr of 0.3 mg/dl above baseline
Cr increase 50% or more in past 7 days
oliguria of <0.5 ml/kg/hr for > 6 hr
sx of arf/aki (lots!)
weakness/lethargy
anorexia
n/v
malaise
pruritus
diarrhea
drowsiness
hiccups
SOB
dizziness
anuria/oliguria
change in volume status/wt
AMS
edema
tachycardia and hypotn suggest __ cause of arf/aki
prerenal
distended bladder, CVA tenderness, enlarged prostate suggest __ cause of arf/aki
postrenal
diagnostic tests for arf/aki (5)
bmp
UA/urine microscopy/urine culture
measurement of urine output
renal US
+/- urine spot
urine spot gives info about (3)
osmolality
urine sodium
urine Cr
life threatening complications of arf/aki (4)
hyperkalemia
fluid overload
uremia
severe metabolic acidosis (pH <7.1)
what do you think when you see pericarditis and AMS in setting of arf/aki
uremia
indications for dialysis in arf/aki (5)
Cr > 5-10 mg/dl
unresponsive acidosis
severe lyte d.o
fluid overload
uremic complications
mc type of arf/aki
prerenal
reduced effective blood circulating to kidney → absolute reduction in fluid volume
prerenal failure
3 ex of prerenal failure
hemorrhage
dehydration
volume depletion → CHF, cirrhosis (hepatorenal syndrome)
is prerenal failure reversible
yes! → kidneys themselves are ok
if underlying cause is corrected
7 causes of true intravascular volume depletion
hemorrhage
burns
diuretics
dehydration
GI losses
vomiting
diarrhea
enteric fisula
5 ex of decreased effective circulating volume
CHF
cardiac tamponade
aortic stenosis
cirrhosis w. ascites
nephrotic syndrome