Chronic Kidney Disease Flashcards
how do we measure GFR in clinical practise?
estimate eGFR from serum creatinine level
- Crockcoft gault
- MDRD 4 variable
- CKD-EPI equation
at what eGFR means you require dialysis?
< 15 ml/min/1.73m2
what is the normal range of GFR?
60-110
what is the gold standard way to measure GRF? and when would this be used?
inulin
if you required an accurate GFR for example if someone was donating their kidney
how do we measure kidney filtering function?
urinalysis (dipstick) protein quantification (protein creatinine ratio PCR)
what molecules cross the glomerular basement membrane and are excreted in the urine?
water
electrolytes
urea
creatinine
what molecules cross the glomerular BM but are reabsorbed in the proximal tubule?
low molecular weight proteins i.e. a2 microglobulin
glucose
what molecules should never be filtered into the tubule?
WBC & RBC
larg proteins i.e. albumin
what is the definition of chronic kidney disease?
presence of kidney damage (haematuria and proteinuria) and/or GFR < 60 that is present for 3 months or more
(if its present for < 3 months = acute kidney injury)
what is the most common cause of chronic kidney disease?
diabetes
what are the causes of chronic kidney disease?
diabetes glomuerlonephritis hypertension systemic diseases i.e. lupus, SLE, amyloidosis renovascular diseases (atheroma) polycystic kidney disease
what are the symptoms of chronic kidney disease?
fatigue / tiredness dyspnoea peripheral oedema LUT symptoms i.e. polyuria, oliguria , nocturia, haematuria pruritus cramps nausea/vomiting anorexia uraemia odour taste disturbance
what are the signs of chronic kidney disease?
pallor pale conjunctive (anaemia) proteinuria (frothy urine) hypertension clubbing , splinter haemorrhages, brown stains of the fingers dehydration signs of kidneys on imaging
what drugs can cause kidney injury?
NSAIDS antibiotics gentamicin penicillamine gold
what tests would you carry out to detect the underlying pathology of chronic kidney disease?
FBC, U&E's urine dipstick urine PCR or ACR USS of kidneys kidney biopsy
what is the main thing to treat in chronic kidney disease and how do we treat it?
hypertension
- ACE inhibitors / ARB’s
what are some of the complications related to reduced GFR?
metabolic acidosis anaemia renal osteodystrophy CV risk electrolyte disturbance - hyperkalaemia fluid overload gout hypetension iatrogenic issues (ned to be aware that drug excretion is altered in CKD)
what are the risk factors for chronic kidney disease?
hypertension diabetes age > 50 childhood kidney disease family history of chronic kidney disease smoking obesity male autoimmmune disorders long term use of NSAIDS
what is a sign of proteinuria?
foamy urine
how can CKD cause metabolic acidosis?
due to declining GFR the kidney isn’t able to excrete acid and generate new bicarbonate
how can CKD cause hyperkalaemia?
due to declining GFR the rate of which potassium is excreted is reduced
What are the GFR levels of stages 1-5 of CKD?
Stage 1: normal or high GFR ( >90) Stage 2: normal or mild reduction in GFR (60-89) Stage 3a: 45-59 Stage 3b: 30- 44 Stage 4: 15- 30 Stage 5: < 15
what are the values of A1, A2 and A3 which classify extent of proteinuria?
A1: < 30mg
A2: 30- 300mg
A3: > 300mg
On imaging, clubbed calyces and cortical scars suggest the damage has been caused by what?
Reflux with chronic infection
And/or ischaemia
What can differentiate upper tract haematuria from lower tract haematuria?
Upper tract haematuria will show dysmorphic RBC and cellular casts on microscopy
Does phosphate increase or decrease in CKD and why?
What is done to resolve this?
Phosphate levels increase because it isnt filtered by the kidney with a low GFR
This results in high serum phosphate levels
Phosphate binders are given to bind to the phosphate ingested (only source of phosphate is food) and excretes it in the urine
Does serum calcium increase or decrease in CKD and why?
Serum calcium decreases because of decreased production of vitamin D (kidneys convert inactive 15 hydroxicalciferol into active vitamin D - 1,25 - dihydroxycalciferol)
- vitamin D/ calcitriol is required to raise Ca levels
CKD also causes an increase in serum phosphorus which increases Ca deposition in bone- therefore increased phosphorus = decreased calcium
What is the best treatment for someone with anaemia due to CKD?
Erythropoeitin
What is the best treatment for bone disease in CKD?
Phosphate binders and diet rich in Ca and vitamin D
