CIS - GFR/Basement membrane dysfunction - McCormick Flashcards
Edemal proteinuria
Loss of plasma proteins - decreased oncotic pressure
Results in peripheral edema
What does Angiotensin II constrict?
Efferent arteriole
1st step in urine formation
Ultrafiltration through glomerular cap
Where is glomerular cap hydrostatic pressure the highest?
At the afferent end - drives filtration
Decreases slightly along its length
Plasma oncotic pressure
Increases along length of GC as plasma is filtered because large proteins remain
Oppose filtration and favor reabsorption
Tamm-Horsfall
Non-plasma proteins
Produced in tubules
Protect apical surface
Casts
Form because of stasis or disease
Normal amount of proteins excreted per day?
140 mg
Can be as high as 200 in kids/preggo
Proteinuria
> 300 mg protein in 24 hours
Polyuria lab value
> 2000 ml
normal 1500
Oliguria lab value
< 500 ml
Problem with lab tests for urine protein?
Normal is 5mg/dl
BUT lower limit of tests is 15 mg/dl
Need to investigate any positive
Complement lab test
If levels are low, it is complexing with bacteria
RBC casts indicate?
Glomerular bleeding
2 Methods for detecting protein in urine?
Dipstick - more sensitive to albumin
Sulfosalicylic acid test - detects all proteins
-ppts out
Physiological causes of proteinuria?
Orthostasis - esp in kids, BM not developed
Strenuous physical activity
4 pathophysiological origins of proteinuria
- Loss of charge barrier
- Loss of size
- Failure of proximal tubule to reabsorb
- Overload proteinuria - increased plasma conc of low MW, filterable proteins
Primary edema
Due to loss of plasma proteins
Na and water retention
Secondary edema
Due to elevated bp
Increase in bp is compensatory mechanism (Na+ and water retention) to counteract cap leakage
Nephrotic syndrome
Scarring
Primary cause of edema?
Hypoalbuminemia
- loss of proteins and retention of Na+ and water
Why do patients with renal problems get hyperlipidemia?
Liver trying to compensate and throws out all proteins/lipids it can - hepatic lipoprotein synthesis
Lipidemia
Due to glomerular capillary damage
Not only are proteins filtered, but also lipids
Maltese cross
Why does pt have normal Na+ in face of increased retention of Na+?
RAAS
Increased body water content due to increased renal water absorption (ADH) and increased thirst
Triggered by decreased plasma volume
