Function test and Disease Flashcards
What is creatinine and why is it used to measure eGFR?
Normal muscle metabolite which can be given as a supplement. It is freely filtered through the GBM and there is little secretion (a little isn’t ideal but best thing we’ve got).
Need to use MDRD formula to compensate for muscle massess of different ages and size etc.
What are the requirements of a substance to measure eGFR?
Fully Filtered at GBM
Not secreted at all within tubule
e.g. inulin (too difficult and expensive)
What are the limitations of measuring eGFR using creatinine?
- Assumes average muscle mass (anorexic or body builders not accounted for)
- not accurate for those under 18
- not accurate above 60ml/min
List the possible colours of urine and their associated diagnosis
Red - haematuria Brown - myoglobin Cloudy - infection Purple - particular infections Green/Blue - certain drugs Frothy - protein
What are the different compositions of kidney stones?
Calcium oxalate Calcium phosphate Struvite - magnesium ammonium phosphate uric acid cystine mixed
What are somem risk factors for the development of kidney stones
genetics obesity high fruit high fibre vegetarian anatomical changes to ureter malabsorption UTIs
How are kidney stones caused?
Nucleation - formation of a nucleus
Supersaturation - there are more solutes in the solution, resulting conglomeration - most likely cause for cystine and uric acid stones
Inhibitor deficiencies - there are natural inhibitors (chelating agents) such as citrate which prevent nucleation, growth, and aggregation of calcium-containing crystals.
How are sturvite stone formed?
requrie alkaline urine with presence of urease containing bacteria. The urease breaks down urea, producing NH4 which increasing pH - induces Mg that is oresent to aggegate into stone
What type of kidney stone is normally associated with gout?
uric acid stone
what type of kidney stones are associated with UTIs?
struvite stones
List causes of CKD
diabetes hypertension polycystic kidney disease obstructive uropathy trauma
Describe the processes involved in the developmetn of CKD from a renal injury
- nephron loss causing glomerular hypertrophy in order to compensate for loss. This therefore increases intra-glomerular pressure
- This results in increased glomerular permeability, resulting in toxicity of mesangial cells
- This results in mesangial expansion, inflammation, fibrosis and scarring
- The expansion of mesangial cells causes increase in angiotensin II production, and therefore an upregulation of TFG-beta, resulting in collagen synthesis and renal scarring
- structural alterations and accompanying biochemical changes account for more scarring and function loss
How do you treat CKD?
dependent on cause - treat underlying condition (e.g. ACE inhibitor, Ca channel blocker)
dialysis
kidney transplant
