Kidney Pathology

Question 1

Where is pain present if it is renal pain?

Answer 1

• a constant dull ache in the loin.

Question 2

What is renal colic?

Answer 2

• Severe waxing and waning pain that is “loin to groin”

* Normally caused by renal stones, clot or sloughed papilla.

Question 3

What is an AKI?

Answer 3

• Acute kidney injury

* Indicates a significant decline in Kidney function over several hours or days.

Question 4

What is an AKI usually secondary to?

Answer 4

• Circulatory dysfunction.

→ Hypotension

→ Hypovolaemia

→ Sepsis

• Urinary obstruction

Question 5

What is nephrotic syndrome?

Answer 5

• Proteinuria (> 3g/day) + Oedema + Hypoalbuminaemia

Question 6

What is the threshold for proteinuria?

Answer 6

> 150mg protein loss per day

Question 7

What is the definition of CKD?

Answer 7

• Chronic Kidney Disease is defined as irreversible, substantial and long standing loss of renal function.
• Classified according to GFR.

Question 8

What can a raised erythropoietin be a sign of?

Answer 8

Hypoxaemia → kidney makes more EPO to transport more O2.

This is secondary polycythaemia.

Question 9

What is it important to remember with Haematuria?

Answer 9

It is often the only sign of Bladder cancer (Frank, painless, >40 yrs, smoker)

Question 10

How do we calculate/stage an AKI?

Answer 10

↑ serum Creatinine + ↓ urine output

KDIGO staging system 1-3 measuring an increase in serum creatinine and decrease in urine output

1. Serum creatinine increase of >26umol/l in 48 hr or 1.5 x baseline with a urine output <0.5ml/kg/h for 6 hrs or more
2. 2-2.9 x baseline cratinine + Low urine output >12 hrs
3. > 3 x baseline creatinine + anurea or 0.3ml/kg/h >24hrs

Question 11

Name 3 renal vascular disease?

Answer 11

• Renovascular disease.
• Haemolytic uraemic Syndrome
• Thrombotic thrombocytopenic purpura

Question 12

What is renovascular disease?

Answer 12

It is defined as stenosis of the renal artery or one of its branches.

• Artherosclerosis (80%), stroke, peripheral vascular disease +other rare causes.

Question 13

What are the signs and tests and treatment for renovascular disease?

Answer 13

Signs:

• refractive ↑BP, Flash oedema (no left ventricular impairment on cardiac echo), Abdominal +/- carotid/femoral bruits.

Test: Renal angiography is gold standard test

treatment: Antihypertensives +/- revascularisation surgery

Question 14

What is Haemolytic uraemic syndrome?

Answer 14

• Characterised By MAHA (microangiopathic Haemolytic anaemia)

• Caused by E.coli (90% strain o157) that attacks endothelial cells triggering thrombosis, platlet consumption and fibrin strand deposition mainly in
renal microvasculature which causes the mechanical destruction of red blood cells.

• Thrombocytopaenia and AKI result.
• Typically affects young people

Question 15

What are the symptoms of Haemolytic uraemic syndrome?

Answer 15

• Abdominal pain
• Bloody diarrhoea
• AKI

Question 16

What are the tests for Haemolytic uraemic syndrome?

Answer 16

• Haematuria/proteinuria
• ↓platelets
• ↓ HB
• Blood film → fragmented red blood cells

Question 17

What is Thrombotic thrombocytopaenic purpura?

Answer 17

• often considered on a spectrum with Haemolytic uraemic syndrome, all patients will have MAHA (often with jaundice) and low platelets.
• It is a either genetic or acquired issues with the cleaving vWf that essentially leads to platelet aggregation and fibrin deposition in small vessels causing microthrombi.

Question 18

What is glomerulonephritis?

Answer 18

Inflammation of the glomeruli and nephrons

Question 19

What happens in the 3 stages to glomerulonephritis damaging the kidney?

Answer 19

• Damage to the glomerulus restricts blood flow leading to a compensatory BP rise.
• Damage to the filtration mechanism allows protein and blood to enter the urine.
• Loss of usual filtration capacity leads to AKI

Question 20

Depending on the magnitude of the damage caused, what are the presentation of damage to the glomeruli and nephrons caused by glomerulonephritis?

Answer 20

1. Blood pressure: normal to malignant
2. Urine dipstick: Proteinuria: mild → severe, haematuria: mild → macroscopic
3. Renal function: normal → impaired

Question 21

Glomerulonephritis can be split into 2 differing syndromes, what are they called?

Answer 21

Nephrotic and Nephritic

Question 22

What is the difference between nephrotic and nephric syndrome?

Answer 22

Nephrotic : BP- normal/mild, Urine - Proteinuria, GFR - Normal

Nephric : BP- Moderate/sever, Urine: haematuria, GFR - Moderate/severe

Question 23

What triad of symptoms constitutes nephrotic syndrome?

Answer 23

1. Proteinuria (> 3g/24hr) causing
2. Hypoalbuminaemia (< 30g/L) and
3. Oedema