8 GFR proteinuria, AKI Flashcards
Normal GFR/CKD grading
>100 ml/min normal 90 - Stage 1 90-60 Stage 2 60- 30 Stage 3 30-15 Stage IV 15-10 Stage V <10 DIALYSIS
Normal Creat
Men 0.9-1.3 mg/dl or 79-114 micromol/L
Women 0.8 to 1mg/dl or 70-88 micromol/L
Kiddos 0.5 to 1mg/dl or .44-88 micromol/L
About how much urine excreted per day?
1-2 liters
Lower limit of UA protein testing
150 mg/ day normal and undetected on UA
Microalbuminuria
30-300mg albumin 24 hrs
20-200 mcg/min
30-300MG albumin/gram creatnine
Diabetic proteinuria GBM
DN with proteinuria have increased GBM thickness
Non kidney proteinuria
Overproduction of proteins by other organs- i.e. Multiple myeloma.
AKI Diagnostic criteria
48 HRS change in:
- increased serum creat of 0.3mg/dl
- 50% increase in creatnine ([creat]1.5)
- oliguria (<400-500) per day
Define:
Oliguria
Azotemia
Uremia
Oliguria <400-500 ml urine/day
Azotemia- Elevated nitrogenous wastes in the blood 2/2 isufficeint filtering
Uremia- Syndrome of toxic effects of nnitrogenous wastes in the blood
Muddy brown casts
Trapping of cellular elements in tubular matrix proteins
Seen in Glomerulitis and Acute tubular necrosis
AKI differentiation
Prerenal: impaired perfusion
Renal: Intrinsic disease (glomerular, tubular, interstitial, vascular)
PostRenal: Obstruction
PRErenal AKI
Dcr renal perfusion -> INC ANGII -> oliguria and sodium retention
- increased urea resorpton - BUN increases 20x creatnine in preAKI
- Reversable if treated within 3-4 days
Prerenal AKI histo
LM: Normal histo
Renal AKI causes
- ATN: ischemic, toxic, mixed
- Inflammatory: GN, tubulointerstitial nephritis, vasculitis
- Embolism, thrombosis, thrombotic microangiopathy
- neoplasm
ATN causes
Ischemia->
- endothelial dysfunction and vasoconstriction
- Tubular injury- Tubuloglomerular feedback, cast obstruction, tubular backleak
ATN histo
Injury and loss of tubular epithelial cells
- Tubular dilation
- thin epithelium
- loss of brush border
- granular casts
- mitosis
- flattening of tubular cells
- necrosis/loss of nuclei
PostRenal AKI/ Obstructive uropathy
- Needs to be ruled out in all patients with oliguria
* Hydronepphrosis
Prerenal Azotemia vs. ATN
FENa
- > 2% is ATN
- normally about 1%
- volume depletion <1%
BUN levels
Normal is 7-20 mg/dL
Prostaglandins in the kidney
Released by macula densa in response to decreased NaCl delivvery, causing vasodilitation of afferent arteriole and release of Renin
