Urinary system

Question 1

What are the most common pathogens causing UTI?

Answer 1

E. coli
Staphylococcus saprophyticus
Proteus mirabilis
Enterococci

More common in recurrent/complicated UTI:
Klebsiella pneumoniae
Pseudomonas aeruginosa
Candida albicans (fungal)

Question 2

How long is the recommended course of antibiotics for uncomplicated UTI in women and men and pregnant women, respectively?

Answer 2

Women: 3 days
Men: 7 days
Pregnant women: 7 days (even in asymptomatic bacteriuria)

Question 3

Regarding nitrites and leukocytes, how does urinalysis aid management of UTI?

Answer 3

Nitrites are a better indication of infection than leukocytes. If both are present the patient should be treated as a UTI. If only nitrites are present it is worth treating as a UTI. If only leukocytes are present the patient should not be treated as a UTI unless there is clinical evidence they have one.
If either are present, a urine sample should be sent to the microbiology lab for culture and sensitivity testing.

Question 4

What ECG changes may be seen in hyperkalaemia?

Answer 4

Tall ‘tented’ T waves
Flattening or absence of P waves
Broad QRS complexes

These often precede the potentially fatal ventricular fibirillation that hyperkalaemia can send the heart into

Question 5

What is the immediate management of hyperkalaemia?

Answer 5

Insulin (e.g. actrapid 10 units) and dextrose (e.g. 50mls of 50%) - drives potassium into cells
Nebulised salbutamol - temporarily drives potassium into cells
Calcium gluconate 10% 10mls iv over 2 mins- stabilises the cardiac muscle cells and reduces the risk of arrhythmias

Dialysis may be required in severe or persistent cases associated with renal failure.

Question 6

What is the definition of CKD?

Answer 6

Abnormal kidney function (based on the presence of proteinuria or GFR <60 ml/minute per 1·73 m²) and/or structure for three months or more

Question 7

What is classed as ‘accelerated progression of CKD’?

Answer 7

A sustained decrease in GFR of 25% or more and a change in GFR category within 12 months, or a sustained decrease in GFR of 15 ml/minute/1.73 m2 per year

Question 8

What are the cut-offs for the stages of CKD based on eGFR?

Answer 8

G1 = eGFR >90
G2 = eGFR 60-89
G3a = eGFR 45-59
G3b = eGFR 30-44
G4 = eGFR 15-29
G5 = eGFR <15 (known as “end-stage renal failure”)

Question 9

What are the cut-offs for the stages of CKD based on Albumin:Creatinine Ratio?

Answer 9

A1 = < 3mg/mmol
A2 = 3 – 30mg/mmol
A3 = > 30mg/mmol

Question 10

What is needed for a diagnosis of CKD?

Answer 10

At least an eGFR of < 60 or, if stage G1 or G2, proteinuria (either A2 or A3) for a diagnosis of CKD; or a chronic structural abnormality of the kidney (e.g. polycystic kidney disease).

Question 11

At what point should a patient with CKD be referred to a renal specialist?

Answer 11

eGFR < 30
ACR ≥ 70 mg/mmol
Accelerated progression - defined as a decrease in eGFR of 15 or 25% or 15 ml/min in 1 year
Uncontrolled hypertension despite ≥ 4 antihypertensives

Question 12

What is the first line anti-hypertensive of choice in patients with CKD?

Answer 12

ACE-inhibitors - beneficial effects on HTN and reducing proteinuria

These are offered to all patients with:
Diabetes plus ACR > 3mg/mmol
Hypertension plus ACR > 30mg/mmol
All patients with ACR > 70mg/mmol

Question 13

What are some common complications of CKD that need to be managed?

Answer 13

Anaemia (normocytic normochromic) - due to reduced EPO production - can treat with exogenous EPO and iron supplementation
Metabolic acidosis - due to reduced bicarb asorption - can treat with supplemental oral sodium bicarbonate
Renal bone disease - less active vit D causes low serum Ca++ (and high PO4- due to reduced excretion) leading to hyperparathyroidism and more osteoclastic activity to try to combat the low serum Ca++ - manage with alfacalcido/calcitriol and low phosphate diet
Hyperkalaemia - due to reduced excretion of K+
Worsening BP control - manage with ACE-inhibitor (but beware hyperkalaemia)

Question 14

What is needed to diagnose AKI?

Answer 14

Rise in creatinine of ≥ 25 micromol/L in 48 hours and/or
Rise in creatinine of ≥ 50% in 7 days (1.5x baseline) and/or
Urine output of < 0.5ml/kg/hour for > 6 hours

Question 15

Give 3 examples of conditions that could lead to AKI for each of the pre-renal, renal, and post-renal causes?

Answer 15

Pre-renal: Dehydration (inadequate intake/vomiting/burns), Hypotension (shock), Heart failure
Renal: Glomerulonephritis, Interstitial nephritis. Acute tubular necrosis
Post-renal: Kidney stones, masses (e.g. abdo mass, enlarged prostate), ureter/urethral stricture

Question 16

What is classed as stage 1 AKI?

Answer 16

Rise in serum creatinine 1.5-2x from baseline OR

urine output =< 0.5ml/kg/hr for 6+ hours

Question 17

What is classed as stage 2 AKI?

Answer 17

Rise in serum creatinine 2-3x from baseline OR

urine output =< 0.5ml/kg/hr for 12+ hours

Question 18

What is classed as stage 3 AKI?

Answer 18

Rise in serum creatinine >3x from baseline OR

urine output =< 0.3ml/kg/hr for 24+ hours

Question 19

What features may be seen in nephritic syndrome?

Answer 19

Haematuria
Oliguria
Proteinuria
Fluid retention (oedema)

Question 20

What features make up nephrotic syndrome?

Answer 20

Peripheral oedema
Hypoalbuminaemia
Proteinuria ( - may notice frothy urine)

(and hypercholesterolaemia)

Question 21

What is the most common cause of nephrotic syndrome in children?

Answer 21

Minimal change disease

Question 22

What is the most common cause of nephrotic syndrome in adults?

Answer 22

Focal segmental glomerulosclerosis

Question 23

What is the most common cause of primary glomerulonephritis (i.e. not caused by another disease)?

Answer 23

IgA nephropathy aka Berger’s disease

Question 24

Typically, how long after a strep infection (e.g. tonsillitis or impetigo) may a patient develop post-streptococcal glomerulonephritis?

Answer 24

1-3 weeks

Question 25

What is the most likely diagnosis in a patient presenting with acute kidney failure and haemoptysis with a positive anti-GBM (glomerular basement membrane) antibodies test?

Answer 25

Goodpasture’s syndrome - anti-GBM antibodies attack glomerulus and pulmonary basement membranes. This causes glomerulonephritis and pulmonary haemorrhage.

Question 26

A histological sample showing “crescentic glomerulonephritis” indicates what diagnosis?

Answer 26

Rapidly progressive glomerulonephritis (RPGN) - often secondary to Goodpasture’s syndrome

Question 27

What may be seen on microscopic analysis of urine that is highly indicative of nephritic syndrome?

Answer 27

Red blood cell CASTS.

The presence of RBCs within a cast is always pathologic and strongly indicative of glomerular damage.

Question 28

In simple terms of pathology, what is the difference between urge incontinence and stress incontinence?

Answer 28

Urge - due to overactivity of the bladder (detrusor) muscle

Stress - weakness of the sphincter allowing urine to leak during coughing or laughing

Question 29

What will be seen on urodynamic studies (only carried out after conservative management measures fail) in a patient with stress incontinence?

Answer 29

The same pattern as seen in normal micturition, except that there will be a passive (i.e. not caused by detrusor muscle contraction, but instead by increased intra-abdominal pressure) increase in vesicular pressure when the patient coughs.

Question 30

After the non-pharmacological methods of weight loss, avoiding caffeine/diuretics/overfilling the bladder, pelvic floor exercises have been tried, what drug may be offered to a patient with stress incontinence?

Answer 30

Duloxetine

Question 31

What will be seen on urodynamic studies (only carried out after conservative management measures fail) in a patient with urge incontinence?

Answer 31

The pattern seen on urodynamics will be the same as that seen in normal micturition, except there will be an increased vesicular pressure and increased detrusor contraction that will occur involuntarily at some stage during filling.

Question 32

As well as bladder re-training, what drugs may be used to help relieve urge incontinence?

Answer 32

Antimuscarinic medication (oxybutinin / tolterodine / solifenacin)
Botox to the bladder neck may also be considered

Question 33

What is the classical and most common presenting feature of bladder cancer (transitional cell carcinoma)?

Answer 33

Painless haematuria

Question 34

What are the criteria for urgent (2 week referral) for urological assessment for suspected bladder cancer?

Answer 34

Adults over 45 years and have unexplained visible haematuria without urinary tract infection.
Adults over 45 years with visible haematuria that persists or recurs after successful treatment of urinary tract infection.
Adults aged 60 and over and have unexplained non visible haematuria and either dysuria or a raised white cell count on a blood test.

Question 35

What grading system is used to grade prostate cancer?

Answer 35

Gleason grading system (made up of 2 parts to give a Gleason score of 2-10, equating to grades 1-5)

Question 36

Within the prostate, where are the majority of cancers located?

Answer 36

Peripheral prostate

most are adenomas

Question 37

What are the vast majority (80%) of urinary stones made up of?

Answer 37

Calcium oxolate

Question 38

What are ‘staghorn calculi’ normally made up of?

Answer 38

Struvite stones (aka magnesium ammonium phosphate)

Question 39

What is the 1st line pain relief option for renal stones?

Answer 39

PR or IM diclofenac

Question 40

What characteristic finding may be seen on chest X-ray of metastatic renal cell carcinoma?

Answer 40

‘Cannon-ball mets’

Question 41

In autosomal dominant polycystic kidney disease (ADPKD), the mutated genes occur on which chromosomes?

Answer 41

Chromosome 16 (PKD1; 85%)
Chromosome 4 (PKD2; 15%)