KIDNEY DISEASE AND RENAL FAILURE

Question 1

what is creatinine?

Answer 1

a waste product that comes from the normal wear and tear on muscles of the body

Question 2

what does normal serum creatinine levels depend on?

Answer 2

age, race, gender, and body size.

Question 3

is serum creatinine used for determining kidney health?

Answer 3

not usually because it varies with different factors e.g. age so there is no ‘normal’

Question 4

how is estimated Glomerular Filtration Rate measured?

Answer 4

with a blood test

Question 5

what’s the relationship between serum creatinine and eGFR?

Answer 5

Creatinine is normally removed from your blood by your kidneys, but when kidney function slows down/ eGFR decreases, the creatinine level rises

Question 6

how is eGFR calculated?

Answer 6

mathematically derived entity based on a patient’s serum creatinine level, age and gender
(remember, race is not considered a factor anymore!)

Question 7

how is chronic kidney disease defined for a diagnosis?

Answer 7

if eGFR is <60ml/min/1.73m squared or there is kidney damage detect for over 3 months

Question 8

what is the ACR?

Answer 8

the albumin to creatinine ratio

Question 9

what are the stages of GFR in chronic kidney disease?

Answer 9

1- >90
2- 60-89
3a- 45-59
3b- 30-44
4- 15-29
5- <15 = kidney failure

Question 10

what are the 3 stages of ACR?

Answer 10

A1 - <3 = healthy
A2 - 3-30 = moderately increased
A3- >30 = severely increased

Question 11

what are some common symptoms of CKD?

Answer 11

nausea, loss of appetite, oedema, shortness of breath, fatigue, haematuria, nocturne, increased need to pee, itchy skin, insomnia, ureic frost

Question 12

what are the most common causes of chronic kidney disease?

Answer 12

hypertension causing hypertrophy in renal arteries and therefore ischaemic injury
diabetes mellitus-

Question 13

how does hypertension cause chronic kidney disease?

Answer 13

Over time, uncontrolled high blood pressure can cause arteries around the kidneys to narrow, weaken or harden. These damaged arteries are not able to deliver enough blood to the kidney tissue.

Question 14

how does DM cause chronic kidney disease?

Answer 14

non-enzymatic glycolisation of efferent arterioles causing mesangial cells to secrete structural matrix

Question 15

what are some less common causes of kidney disease?

Answer 15

lupus, rheumatoid arthritis, atherosclerosis, IgA nephropathy, membranous nephropathy, NSAIDs, lithium, tumours, stones, fibrosis, HIV, TB

Question 16

what is renal artery stenosis?

Answer 16

the narrowing of one or more renal arteries which prevents normal amounts of oxygen-rich blood from reaching your kidneys.

Question 17

what are complications of chronic kidney disease?

Answer 17

increased risk of CVD, infections and loss of homeostatic functions e.g. hypertension, oedema metabolic acidosis, mineral-bone disease, anaemia, muscle weakness, death, hyperkalaemia

Question 18

what are the 3 stages of acute kidney injury?

Answer 18

stage 1 = 50-100% increase of creatinine from baseline or <0.5ml/kg/hour of urine for 6 hours

stage 2 = 100-200% increase of creatinine from baseline or <0.5ml/kg/hr for 12 hours

stage 3 = >200% increase of creatinine from baseline or <0.3ml/kg/hr for 24 hours/anuria

Question 19

what is acute kidney injury?

Answer 19

a sudden episode of kidney failure or kidney damage that happens within a few hours or a few days.

Question 20

what medications can cause kidney disease?

Answer 20

amino glycoside antibiotics, NSAIDs and ACEi

Question 21

what is pre-renal acute kidney disease?

Answer 21

occurs when a sudden reduction in renal hypoperfusion which causes a loss of kidney function due to low GFR. this leads to azotemia.
e.g. renal artery stenosis, liver failure, hypotension, sepsis

Question 22

what is renal AKI?

Answer 22

diseases affect kidney tissue which decreases GFR and causes accumulation of waste products in the blood (azotemia)
e.g. interstitial nephritis, drug toxicity

Question 23

what is post-renal AKI?

Answer 23

obstruction to the urine system causing increased nitrogenous compounds in the blood and causing pressure to back up into the kidneys, reducing the pressure gradient between arterioles and tubules, lowering GFR
e.g. stones, benign prostate, blocked catheter

Question 24

what are the signs of nephrotic syndrome?

Answer 24

heavy proteinuria with >3g protein collected in 24 hours
frothy urine with fatty casts
low serum albumin causing peripheral and peri orbital oedema
weight gain due to fluid retention
loss of appetite
fatigue
increased creatinine
high bp

Question 25

what isnephrotic syndrome?

Answer 25

when the Glomerular filtration barrier is damaged leading to increased permeability and protein leak

Question 26

what are the primary causes of nephrotic syndrome?

Answer 26

minimal change disease
membranous nephropathy
focal segmental glomerulosclerosis

Question 27

what are secondary causes of nephropathy?

Answer 27

diabetes mellitus, lupus erythematosus, amyloidosis

Question 28

what is minimal change disease?

Answer 28

T cells release glomerular permeability factor which specifically damages the foot processes of the podocytes, causing effacement and allowing negatively charged molecules into the glomerulus- Selective proteinuria.

Question 29

what is focal segmental glomerulosclerosis?

Answer 29

scarring of segments of the glomerulus, causing damage which lets protein into the urine

Question 30

what is membranous nephropathy?

Answer 30

immune complexes are deposited in the glomerular filtrate causing damage and allowing proteins into the nephron

Question 31

what is diabetic glomerulonephropathy?

Answer 31

when theres a lot of glucose in the blood, it can stick to proteins (non-enzymatic glycation). This can thicken the basement membrane of the efferent arteriole, increasing the pressure in the glomeruli. This leads to an increase in GFR. In response, mesangial cells secrete structural matrix, expanding the size of glomerulus

Question 32

what is systemic amyloidosis?

Answer 32

tissue damage occurs from amyloids (abnormal proteins) depositing in kidneys

Question 33

what are complications of nephrotic syndrome?

Answer 33

thromboembolisms, infections, hyperlipidaemia, malnutrition, AKI, CKD

Question 34

whats the treatment of nephrotic and nephritic syndrome?

Answer 34

diuretics, salt restriction, ACEi or ARB. thrombi-prophylaxis and treating underlying cause
meds for inflammation in nephritic syndrome

Question 35

what are the signs and symptoms of nephritic syndrome?

Answer 35

proteinuria, haematuria, hypertension, oedema, oliguria, increased creatinine

Question 36

what is the cause of nephritic syndrome?

Answer 36

inflammation that damages the glomerular basement membrane leading to haematuria and RBC casts in urine. Eventually this can lead to renal failure e.g. systemic lupus erythromatosous, bacterial endocarditis, HCV, post infectious glomerulonephritis

Question 37

why can NSAIDs cause kidney disease?

Answer 37

buprofen and other NSAIDs block prostaglandins which normally dilate afferent blood vessels. This causes a drop in renal perfusion pressure and subsequent decrease in glomerular filtration.

Question 38

how do ACEi and ARB cause kidney damage?

Answer 38

they vasodilator efferent arterioles in the kidneys causing a drop in renal perfusion pressure and subsequent decrease in glomerular filtration.

Question 39

discuss why ethnicity has been removed as a factor for calulating GFR?

Answer 39

a study was carried out that noticed that back study participants had, on average, a high creatinine than white participants so the study assume they had higher muscle mass. To prevent this elevation, researched added a factor of 1.2 into the equation when calculating GFR. the consequences of this are having to wait longer to qualify for s kidney transplant, more likely to be diagnosed with kidney disease later in life, and how do you classify mixed races