Abnormalities of urine

Question 1

What are some of the renal causes of Haematuria?

Answer 1

Cancer
Infection - Pyelonephritis
Congential/Genetic - Polycystic kidney disease
Immune - Glomerulonephritis, Tubulointerstitial nephritis

Question 2

What is Glomerulonephritis?

Answer 2

Collection of inflammatory kidney diseases characterised by inflammation of the glomeruli or small blood vessels

Question 3

What is Tubulointerstitial nephritis?

Answer 3

Primary injury to renal tubules/interstitium resulting in decreased renal function
Acute form often due to drug reactions or infections
Symptoms may include fever, weight gain due to fluid retention, change in urine output, N&V, rash, changes in consciousness

Question 4

What are some of the extra renal causes of Haematuria?

Answer 4

Trauma - Stones, catheter
Infection - cystitis, prostitis, urethritis
Cancer - bladder, prostate
Bleeding diathesis (Hypocoagulobility causing increased risk of bleeding)
Drugs eg NSAIDs, Cephalosporins, Furesmide

Question 5

What are some of the causes of Proteinuria?

Answer 5

DM
Minimal change GN
Amyloidosis
SLE
HTN
ATN
UTI

Question 6

What can cause Microalbuminuria?

Answer 6

DM
Increased BP
Minimal change GN

Question 7

What can cause RBC casts in the urine?

Answer 7

Glomerular haematuria

Question 8

What can cause WBC casts in the urine?

Answer 8

Interstitial nephritis

Pyelonephritis

Question 9

What can cause Tubular casts in the urine?

Answer 9

Acute tubular necrosis

Can be due to toxic (Vancomycin, Furesmide, Phenytoin, Ranitidine) or ischaemic causes

Question 10

How poor is renal function for creatinine to be increased in urine?

Answer 10

50% drop in eGFR

Creatinine synthesised in muscle turnover so can increase/decrease with age, sex and ethnicity

Question 11

What can cause an increase in urea in the urine?

Answer 11

High protein diet
Upper GI bleed
Supplements

Question 12

What can cause a decrease in urea?

Answer 12

Hepatic impairment

Decreased flow can cause increased urea reabsorption

Question 13

What does an isolated increase in urea suggest?

Answer 13

A decrease in flow - hypoperfusion, dehydration

Question 14

What does an increase in urea and creatinine suggest?

Answer 14

Decreased filtration eg due to renal failure

Question 15

Why is creatinine clearance useful?

Answer 15

Can roughly approximate GFR
Requires urine collection over 24hrs
Doesn’t take age/sex/race/muscle mass into consideration

Question 16

Why is eGFR better than GFR alone?

Answer 16

Modified to account for age, sex, race, serum creatinine