Final: Ch 26 Acute Renal Failure & Chronic Kidney Disease Flashcards
acute renal failure is the rapid decline in _____ function and high ____ _______ waste levels
renal, high blood nitrogenous waste levels
common cause of ICU death
clinical presentation of acute renal failure
high serum BUN and creatinine
low GFR
filtration definition
blood to urine (glomerulus)
anything smaller than a protein
reabsorption definition
urine to blood
proximal/distal convoluted tubules
loop of henle
secretion definition
blood to urine
K+, H+
creatinine clearance is ~ what
the GFR
urine formation begins with _______
filtration
filtrate is modified by ______ & _______
reabsorption & secretion
definition of GFR
volume of fluid filtered from blood plasma to urine/min
creatinine is filtered at the ______; not ______ or ________
glomerulus, secreted, reabsorbed
the amount of creatinine filtered = the amount _______
excreted
calculation for amount of creatinine filtered
filtered = [creat]plasma x GFR
calculation for amount of creatinine excreted
excreted = [creat]urine x volume of urine
prerenal failure
decreased renal blood flow
causes of prerenal failure
hypovolemia
HF
shock
some meds (contrast dye)
prostaglandins dilate the ______ arteriole artery
afferent
NSAIDS can cause renal failure in people with…
decreased function
prerenal failure results from renal ______ when RBF
ischemia, 25%
prerenal failure levels
U/O & fractional excretion of Na are low, but SG is high
BUN more elevated than serum creat
at low GFR, urine flow in tubules is _______
sluggish
urea is small and high reabsorption when flow is slow
creat is larger and not reabsorbed
postrenal failure
obstruction in ureter or bladder
stones, rumors, neurogenic bladder (spinal injury)
re-establish flow, surgically if necessary
intrinsic renal failure
damage to the kidney - glomeruli, tubules, or interstitium
causes: ischemia, toxins, tubular obstruction
acute tubular necrosis is the most common cause of….
intrinsic renal failure
acute tubular necrosis (ATN)
destruction of tubular epithelium
caused by ischemia, sepsis, toxins, tubular obstruction
may or may not be reversible
acute tubular necrosis is seen in…
major surgery with blood loss
massive infection
trauma
burns
ATN complicates the use of what
potentially nephrotoxic medications
aminoglycosides (gentamycin), chemo, contrast dyes
ATN hemoglobin/myoglobin, uric acid
Hb, uric acid, myoglobin in urine causes obstruction
Hb from blood rxn
myoglobin from muscle trauma, rhabdomyolosis
stages of ATN
onset
maintenance
recovery
onset stage of ATN
hours to days
happens when the initiating event is occuring
maintenance stage of ATN
low GFR, oliguria, edema, electrolyte imbalance
low dose dopamine may improve renal blood flow
recovery stage of ATN
nephrons are repairing
gradual increase in U/O
fall in serum creatinine
Dx, Rx of ATN
Dx: determine cause
Rx: treat symptoms/cause, hemodialysis
in prerenal failure the BUN:Creatinine ratio is what
fraction of excreted Na
SG
greater than 20:1
less than 1%
greater than 1.02
in intrarenal failure the BUN:Creatinine ratio is what
fraction of excreted Na
SG
10:1 to 20:1
greater than 1%
1.01 - 1.02
the ultrasound for postrenal failure shows
hydronephrosis
a nephrology consult involves a ________, and a urology consult involves a _______
specialist, surgeon
chronic kidney disease classification
GFR used to define 5 stages
stage 2: modest decline in GFR (hypovolemia)
kidney failure stage 5: very low GFR requires dialysis (permanent loss of nephrons)
CKD can result from conditions (3)
diabetes
HTN
glomerulonephritis
what is the best measure of kidney function
GFR - measure of functional nephrons
falls as # of working nephrons falls
constant = GFR x [creat]p so if GFR is high, then [creat]p is…
low
GFR can be measured by ________ clearance or calculated from….
creatinine clearance
serum creatinine
albuminuia is a marker for _____ injury
nephron
in CKD there is an accumulation of what
nitrogenous waste
BUN is high
uremia
CKD causes what imblances
electrolyte, cardiovascular, acid/base
reduced ability to regulate Na
sodium retention –> volume expansion –> HTN CHD HF uremia –> pericarditis
hyperkalemia
acidosis
calcium and phosphate imbalances in CKD
phosphate is high, calcium is low
high PTH –> osteoclast stimulation
sometimes osteoblasts/osteoclasts inhibited
decreased mineralization occurs (osteodystrophies)
should you restrict high phosphate foods (milk) and give vitamin D in CKD?
yes
can CKD cause anemia?
yes
low EPO
GI symptoms of CKD
N/V - urea in intestinal flora
neuromuscular symptoms of CKD
peripheral neuropathy
encephalopathy
other symptoms of CKD
poor immune response
poor skin integrity
poor drug elimination
slowing progression of CKD
BP target 125/65 - ACEI & ARBS
glucose control for those w/ diabetes
stop smoking
hemodialysis for CKD
blood exchange with dialysis fluid
excess H2O, urea, K+ leaves blood
may need to replace bicarb
peritoneal dialysis
uses peritoneal memb. as dialysis memb.
infuse 1-3L of soln and equilibriate for 30min
allow to run out
repeat 4x/day
advantage: can be done at home
transplantation for CKD
from cadaver or living donor
improved anti-rejection meds have increased success
dietary management of CKD
restrict protein
feed fat/carbs to insure adequate calories
restrict Na/H2O
Type of Acute renal failure associated w/ highly concentrated urine is…
Pre-renal failure
Chronic renal failure produced what acid/base abnormality the most
Metabolic acidosis
