module 12 acute tubular necrosis and CKD Flashcards
acute tubular necrosis mortality predictors
oliguria high severity of illness acute MI stroke seizure chronic immunosuppression need for ventilation
ATN prodromal phase
insult to kidney has occured
ATN oliguric phase
2-8 weeks with UO of 50-400mL/day
oliguria and progressive uremia; dec. GFR, hypervolemia
- fluid excess, inc. K, uremic syndrome
dialysis may be required
ATN postoliguric phase
diureses; tubular function impaired and azotemia continues
fluid volume deficit until kidneys recover
- 2-10 days, up to a year
full recover: BUN/creatinine normal
prerenal lab findings AKI
SG: >1.020
BUN/creatinine ratio: >20:1
urine Na: < 10
urine sediment: few hyaline casts
intrarenal lab findings AKI
possible proteinuria SG: 1.010-1.020 BUN/creatinine ratio: 10-20:1 urine Na: >20 urine sediment: tubular, RBC, and WBC casts
ATN patho
ischemia or nephrotoxin Inflammation and tubular injury -> inflammatory cells -> cast formation -> tubular obstruction -> inc. tubular intra-luminal pressure -> tubular backleak, oliguria, dec. GFR dec. O2 to outer medulla -> vasoconstriction
ATN tubule cell injury Reversible patho
- loss of polarity
- > inc. distal Na
- > inc. tubuloglomerular feedback
- > vasoconstriction
- > dec. GFR and oliguria
- detachment
- > obstruction by casts and tubular back leak
- > inc. intratubular pressure and dec. tubular flow
- > dec. GFR and oliguria
ATN tubule cell injury irreversible patho
necrosis and apoptosis
- > tubular back leak
- > dec. tubular flow
- > dec. GFR and oliguria
ATN endothelial dysfunction patho
vasoconstriction
- > RAAS
- > inc. endothelin, dec. NO, dec. PGI2
- > dec. GFR and Oliguria
CKD progressive process
chronic kidney disease -> chronic renal failure -> end-stage renal disease
- ESRD: requires dialysis
Linked with comorbidities
- HTN, DM
dec. kidney function or kidney damage of 3 mo.
GFR < 60mL/min for 3 mo.
GFR reduction occurs with
nephron loss
kidneys compensate until 75-80% of nephrons are damaged/nonfunctional
stages of CKD
each stage higher the GFR and kidney function dec.
1-5
Stage 1 and 2 CKD
labs normal
asymptomatic with some kidney disease
minimizing risk factors
initial decrease in GFR
stage 3 CKD
symptoms may appear and treatment may be needed.
HTN
Stage 4 CKD
planning for dialysis or transplant should begin
s/s very apparent
Stage 5 CKD
Renal replacement therapy needed or death will ensue
CKD risk factors
DMT2 HTN recurrent pyelonephritis glomerulonephritis polycysitic kidney disease family hx exposure to toxins >65 ethnicity: black, white, mexican-american electrolyte and fluid imbalance
stages of CKD according to nephron loss
dec. renal reserve
- <75% nephron loss
- no s/s, BUN/creatinine nml
Renal insufficiency
- 75-90% nephron loss
- polyuria, nocturia, slight in. BUN/creatinine
- control with diet and medication
End stage:
- >90% nephron loss
- azoztemia/uremia, fluid and electrolyte abnomal, osteodystrophy, anemia, dialysis or transplant needed.
CKD and primary foci
appropriate management of ATN
blood glucose control
aggressive management of HTN
HTN, cardiovascular disease, and CKD
Hypervolemia, escalated atherosclerosis, inc. RAAS/SNS activity
cardiovascular disease is both a risk factor and side effect of CKD
metabolic acidosis and CKD
kidneys dont secrete H+
will be exchanged for intracellular K+
-> hyperkalemia and dec. pH
Kidney does not produce Bicarb -> dec. pH
uremic syndrome
retention of metabolic wastes -> impaired healing
electrolyte imbalance and CKD
retained K+, phosphorus, mag
loss Ca
