Proteinuria Flashcards
what is proteinuria a sign of
kidney disease
when should you test for proteinuria
in routine medical consultations - good screening tool
recent onset of oedema (including periorbital and sacral)
unexplained ascites or pleural effusions
as part of care of patients with diabetes or hypertension
if a systemic disease is possible
what are two signs of protein in urine to the naked eye
bubbles form when shaken - ‘detergent effect’
protein collects as white substance when urine is boiled
what are the steps for testing for proteinuria
- urine dipstick
- quantify the actual quantity using the albumin/creatinine ratio
- test renal function
- never ignore proteinuria
what level of proteinuria implies intrinsic renal disease and what needs to be done below this level
2+, at this level the proteinuria is very unlikely to be explained by asymptomatic infection
1+ or less needs further investigation
is it appropriate to respond to proteinuria by sending a mid stream urine sample to exclude infection
no
how many urine samples are required to calculate the albumin creatinine ratio
one
taken any time of day
how do you calculate the approximate albumin creatinine ratio for 24h
ACR of one sample multiplied by 10
an ACR of 100 shows what
may be a sign of very significant renal disease
what is a normal ACR
<3.5
an ACR of 3.5-30 is classified as what
microalbuminuria
an ACR >30 is classified as what
(macro)albuminuria
what is the MDRD formula
a formula used to calculate eGFR which takes into account sex, age, race and creatinine
what is radioisotope GFR and when is it used
inject labelled chemical and see how long it takes to be cleared
only done when in doubt about kidney function or in kidney donor assessment
what racial groups may have less nephrons
black and asian
what are the three layers of the nephron filter
podocytes
glomerular basement membrane
glomerular endothelium
what is the cause of congenital nephrotic syndrome
mutation in podocyte-specific gene (e.g. nephrin)
what does the presence of blood and protein in the urine imply and what should be done about this
glomerular disease (kidney filter is diseased)
urgent need to test excretory kidney function and consider systemic diseases (e.g. vasculitis and lupus)
what is the earliest clinical sign of diabetic nephropathy
microalbuminuria
what is the most likely cause of hypertension with albuminuria
primary renal cause
why is it important to pick up microalbuminuria
it is useful for risk stratification and is a modifiable risk risk factor for CVD
what does nephrotic syndrome comprise of
oedema
heavy proteinuria
hypoalbuminaemia
what three things are you more at risk of with nephrotic syndrome
thrombosis
infection
hyperlipidaemia (often severe)
is nephrotic syndrome associated with impairment of excretory kidney function
can be but isn’t always
main symptoms of nephrotic syndrome
severe lethargy
reduced exercise tolerance
nausea
loss of appetite
causes of nephrotic syndrome
glomerulonephritits
diabetes
infections (hep B/C, malaria, HIV)
amyloid
what is haematuria a sign of
serious systemic disease for which diagnosis and treatment is very urgent
shouldn’t be dismissed as due to urine infection
