CSIM renal medicine Flashcards
what role do the kidneys have in metabolism?
excrete metabolites in urine
metabolise vit. D and some proteins
what is nephrotic syndrome and what are the clinical signs
loss of protein through the kidenys
protein urea >3.5g / day
oedem
hypoalbuminaemia
hyperlipidaemia
the 3.5 is arbitrary - it just needs to be enough to make you hypoalbuminaemic
what is nephritic syndrome?
inflammation of the kidneys leading to:
haematurea
protein urea
hypertension
oligourea
what will the creatinine be like in nephrotic syndrome?
normal
what will the urine look like in nephrotic syndrome?
frothy due to the protein
in suspected renal disease how should the BP be assessed?
lying and standing
causes of AKI
PRE: Secondary to sepsis, low BP, nephrotoxins etc
INTRINSIC: nephritis ( inflammation)
POST- obstruction
what are the symptoms of advanced kidney disease
Tiredness (anaemic) swollen ankles, feet or hands (due to water retention) shortness of breath nausea blood in the urine
symptoms of acute glomerular nephritis
AKI -> Oedema, hypertension Smoky or coca- cola coloured urine Hypertension, reduced urine volumes Systemic symptoms- rash, haemoptysis
could be asymptomatic
where does the creatinine in the urine come from?
mostly freely filtered through glomerular
some secreted in proximal tubules
what information is used to get eGFR?
creatinine
sex
ethnicity (black or other)
age
why dont we measure the actual GFR anymore?
requires 24hr urine collection
what kind of kidney injury does proteinurea indicate?
Marker of intrinsic renal disease
2 ways of quantifying proteinurea and whats the difference?
albumin : creatinine for small protein urea
protein : creatinine for large protein urea
what is a hyaline cast? and what is it dependent on
glycoprotein formed in the renal tubules
seen in small quantities in normal adults
dependent on urine flow and pH
what can light microscopy of a MSU tell you
red cell casts : diagnostic of glomerular disease
white cell casts : inflammation or infection
organisms and white cells during a urinary infection
tubular debris : in acute tubular necrosis
which scan will most kidney patients get?
USS
what does a chronically damaged kidney look like on USS?
shrunken
less well demarcated regions
what do the inflammatory cells in the kidney look like?
crescent moons
in monitoring urine output, when should you catheterise?
only if they cant collect urine themsleves
how small does a molecule have to be to filter through the glomerulus?
<30A
why kidney damage in trauma ?
large release of protein is neprotoxic
how many red cells is normal in the urine?
1-2 per micro litre
conveniently this is also the cut off for what dipstix can detect
causes of haematuria that aren’t related to glomerular disease?
renal malignancy
renal stone disease
bladder tumours
which protein does the kidney produce and why?
Tamm-Horsfall
thought to protect against infection
what is normal protein in urine?
<150mg / day
this is NOT detectable on dipstix
what does the amount of protein urea tell you about where the pathology is?
> 1 g / day = glomerular disease
<1 g / day = somewhere after the glomerular e.g. tubules, upper/ lower UTI, stones
benign causes of proteinurea
exercise
orthostatic
two non-renal conditions that cause protein urea?
fever
HF
effect of low albumin on lipoprotein level?
increases
liver is trying to make more proteins which includes cholesterol etc
effect of nephrotic syndrome on clotting?
pro-thrombotic due to loss of anti-thrombin protein
why at risk of infection in nephrotic syndrome?
loose immunoglobulins
why do you need to include creatinine when measuring urine protein?
to account for hydration status
5 things that effect serum creatinine?
production:
liver function
muscle mass
muscle metabolism
diet (if very malnurished)
RENAL DISEASE
the better you filter, the ____ your serum creatinine will be
LOWER
two people with the same serum creatinine, one with large muscle mass the other with small muscle mass. which has the lower GFR?
small muscle mass
the large guy/girl has more creatinine due to large amount of muscle
3 main causes of nephrotic syndrome?
glomerulonephritis
DM
amyloidosis
3 main primary disease of nephrotic syndrome
minimal change
membranous
focal segmental glomerulosclerosis
what kind of glomerulonephritis is associated with malignancy?
membranous
how to manage persistent low levels of proteinurea?
if all else normal monitor but no need to intervene
how can AKI be distinguished from CKD?
previous bloods
repeate creatinine 6 hrs later
USS
Hx
how is post-renal AKI diagnosed?
USS: gross dilation downstream of kidneys due to obstruction
main causes of post renal AKI?
stones
older patients:
prostate
cancer
define azotaemia
appropriate response to reduced renal perfusion:
increased nitrogen
causes of pre renal azotaemia?
decreased cardiac output decreased effective circulating volume: hypovolaemia (reduced fluid intake etc) volume redistribution bleeding renal vascular disease drugs
definition of AKI we were told to use?
increase in serum creatinine of >0.3mg/dl in 48hrs
which drugs can cause pre renal azotaemia?
NSAIDS
ACE i
cyclosporin (immunosuppressant)
two types of tubulo-interstital disease?
acute tubular necrosis
acute allergic interstitial necrosis
what two things can cause ATN?
toxins e.g. aminoglycosides, radio contrast
ischaemia due to hypo perfusion
which drugs commonly cause an acute allergic interstitial necrosis?
NSAIDS bendrofluazide frusomide PPIs penicillin
what Ix distinguishes between glomerular disease and tubulo-intertial disease?
urinalysis
what are the features of rapidly progressive GN?
haematuria
proteinurea
oedema
hypertension
examples of RPGN
goodpastures syndrome lupus post infective Wegeners microscopic polyangitis
all causes of haematurea
Urinary tract infection Catheter trauma Infarction Stone Tumour Glomerulonephritis
finding of blood and protein in urine should prompt what?
microscopy and culture
how does urine microscopy differentiate between Glomerular versus Tubulo-interstitial causes of AKI?
GN: red cell casts and inflammatory cresents
what are the three types of RPGN?
type I - Anti-glomerular basement membrane antibody disease (Goodpastures syndrome)
type II - immune complex
lupus nephritis
post-infectious
type III - pauci immune (pauci as in latin for few)
Wegener’s granulomatosis
Microscopic polyangiitis
what is the triad for Goodpastures syndrome?
anti- GBM antibodies
pulmonary haemorrhage
RPGN
what organism is responsible for post infectious RPGN?
group A, ß-haemolytic streptococcus
what does a low compliment tell you about the cause of RPGN?
likely to be post infectious
diagnosis of lupus nephritis?
ANA
renal biopsy
immunoflourescence shows ‘full house’ immune deposits
what type of RPGN is SLE?
type II - immune complex
what type of RPGN will give systemic symptoms of night sweats, weight loss, fever, lethargy?
type III - pauci immune
pANCA is associated with what type of RPGN?
type III - pauci immune - microscopic polyangitis
what is Wegeners granulomatosis and what auto-antibody is associated with it?
RPGN
cANCA
what auto-antibody is associated with microscopic polyangitis?
pANCA
when would you NOT renal biopsy RPGN?
in type II - immune complex if there is sufficient clinical evidence that it is post-infectious (culture, reduced compliment and clinical picture)
what % of hypertension is secondary?
10%
causes of secondary ht?
CRAP C onns C ushings C oarctation of the aorta R enal A cromegaly P haechromocytoma P arathyroidism (HYPER) P ills
renal causes of hypertension?
GN
renal artery stenosis
autosomal dom. polycystic KD
pyelonephritis
what is the problem is Conns?
too much aldosterone (produced in the adrenals)
what is the problem in Cushings?
too much cortisol
what is the problem in phaeochromocytoma?
too much catecholamines
below what age do you start thinking ht is secondary?
40
what is first line imaging if suspecting Conns?
CT adrenals
what is the Ix for phaeochromocytoma?
serum catecholamines and serum metanephrines
where is renin made?
kidney- juxtaglomerular apparatus
what does an ACE i do to the kidneys?
stops all the things angiotensin II would do therefore:
vasodilation
reduced aldosterone production (reduced Na retention)
what clinical signs make you think ht is due to coarc1tation of the aorta?
scapular vessels
absent pulses
machinery mummer
radio-radial delay
food that can raise BP? other than salt obvs
liquorice
what sign of chronic ht is seen in the eyes?
papiloedema
what effect on the heart does chronic ht have?
LV hypertrophy
how does increased filtration of proteins cause CKD?
nephrotoxc inflammatory process
on USS kindey, what would one normal and one small kidney suggest?
renal artery stenosis
1st line drug for CKD? why?
ACE-i to reduce proteinuria
If you want to increase your dietary protein for gains, what should you do?
Drink the piss of a patient with nephrotic syndrome
which of the following are complications of CKD?
Uraemia Hypokalaemia Acidaemia Mineral bone disorder Dehydration Anaemia
Uraemia - YES Hypokalaemia - NO (HYPERKALAEMIA) Acidaemia - YES Mineral bone disorder - YES Dehydration - NO (FLUID OVERLOAD) Anaemia - YES
why anaemia in CKD?
kidneys produce erythropoiten
why hyperkalaemia in CKD?
unable to actively remove K
effect on pH of CKD?
acidaemia - role in acid base regulation
what is the clinical manifestation of high phosphate?
pruitis
what is the tx for low erythropoeitin?
EPO and iron
what is better transplant or dialysis?
transplant
cheaper
restores all function
knock on effect for the rest of the family
what is the hall mark of interstitial nephritis?
white cell cast
need a biopsy to SHOW it’s that but you can infer it from the lack of another cause
another name for Good pastures syndrome?
anti glomerular basement membrane disease
what do crescent cells tell you?
indicate severe aggressive immune damage guide prognosis (10% good 100% BAD)
what first Ix in a women with recurrent UTIs?
US renal tract
Mx of recurrent UTIs?
low does prophylactic abx
one off abx after intercourse
4 indications for urgent dialysis?
uraemia
severe acidosis
high potassium
refractory pulmonary oedema
when do you get re cell casts?
when there is significant haematuria i.e. when there is inflammation in the kidney…
not when there is just a bit of nephropathy
effect of CKD on iron metabolism?
inefficient metabolism: iron is less readily available for haemoglobin synthesis
calcium in CKD? why?
low
functional vit. D deficiency
PTH in CKD? why
high due to low calcium
what is the target BP in CKD?
130/80
why give drugs to bind phosphate in CKD?
prevent absorption- it will be high :(
