Renal Stones and Haematuria

Question 1

What aspects of history are important to ascertain in the case of an acute stone episode?

Answer 1

Pain characteristics
Any indications of sepsis
Previous stone episodes and outcome
Complicating factors
Pain score
FHx if young

Question 2

What complicating factors are important to consider in an acute stone episode?

Answer 2

Pregnancy

Pre-existing renal impairment

Question 3

DDx for renal/ureteric colic

Answer 3

Ruptured AAA
Testicular/ovarian torsion
Appendicitis

Question 4

What features on examination are important for an acute stone episode?

Answer 4

Temperature
Other possible causes of pain
Features of peritonism (usually none)

Question 5

What are the 6 types of stones, from most to least common?

Answer 5

Calcium oxalate
Uric acid
Magnesium ammonium phosphate (struvite)
Cystine
Other: matrix (mucoproteins and mucopolysaccharides), protease inhibitor-induced

Question 6

What is the pathogenesis of magnesium ammonium phosphate stones?

Answer 6

Infection by urea-splitting GNRs (e.g. proteus, pseudomonas, klebsiella but NOT E. coli)

Question 7

What is the pathogenesis of cystine stones?

Answer 7

AR defect in small bowel mucosal absorption and renal tubular absorption of dibasic AAs which results in “COLA” urine (citrine, ornithine, lysine, arginine) and cystinuria

Question 8

How does cystine stone disease usually present?

Answer 8

Aggressive stone disease in children and young adults, with a FHx of recurring stones

Question 9

What types of stones are radiolucent?

Answer 9

Uric acid

Cystine can be

Question 10

List 2 risk factors for urolithiasis

Answer 10

Dehydration

Diet (animal protein, sodium)

Question 11

What tests are required for the acute work-up of a stone episode?

Answer 11

FBE
UEC
Serum Ca2+ and uric acid
MSU
KUB XR
CT-KUB (or CT-IVP)

Question 12

Where are stones usually located in an acute stone episode?

Answer 12

Usually ureteric (renal stones not typically associated with an acute presentation)

Question 13

What are the 7 indications for intervention with an acute stone episode?

Answer 13

Infection/sepsis
Renal impairment
Bilateral obstructing calculi
Solitary kidney (anatomically or functionally)
Inability to control symptoms (refractory pain, usually with repeat presentations)
Prolonged obstruction
Unlikely to pass spontaneously

Question 14

How long does it take for complete ureteric obstruction to result in permanent renal damage in dog studies?

Answer 14

4/52

Question 15

How should patients with an acute stone episode be managed acutely?

Answer 15

Pain relief (NSAIDs, opioids, paracetamol)
Hydration
Admission if acute intervention required; if not, surveillance/medical expulsive therapy (a blockers) with early follow-up

Question 16

What is the most common causative organism in cases of obstructive pyelonephrosis?

Answer 16

GNB (E. coli)

Question 17

How should obstructive pyelonephrosis be managed?

Answer 17

IV Abx (coverage for GNs and enterococcus)
Urgent decompression (nephrostomy, stent)
Supportive care (fluids, monitoring, ICU if necessary)

Question 18

What factors influence likelihood of spontaeous passage of stones?

Answer 18

Maximum size in transverse plane
Location
PHx of stone passage

Question 19

When is conservative management appropriate?

Answer 19

Size

Question 20

What is the rationale behind the use of a blockers for medical expulsive therapy in the treatment of stones?

Answer 20

Ureteric wall contains a1 adrenergic receptors that mediate smooth muscle contraction
a blockers relax ureteric wall

Question 21

Describe the efficacy of a blockers for MET as compared with Ca2+ channel blockers and steroids

Answer 21

More effective (increase stone passage by ~30%, decrease time to stone passage by 2-4 days, decrease pain)

Question 22

How should a blockers be administered?

Answer 22

Tamsulosin 0.4 mg daily x 2/52

Question 23

What are the 3 surgical options for treatment of urolithiasis?

Answer 23

JJ stent and delayed management
Ureteroscopy and lithotripsy (laser or pneumatic)
Shock wave lithotripsy (ESWL)

Question 24

Describe the pathogenesis of uric acid stones

Answer 24

Form in acidic urine (pH

Question 25

How can uric acid stones be treated?

Answer 25

Dissolved with urinary alkalinisation (target pH >6.5; monitor efficacy with urine pH strips) Allopurinol if serum uric acid levels elevated High fluid intake (increased passage and alkalinisation)

Question 26

What agents are used for urinary alkalinisation?

Answer 26

Potassium citrate or sodium bicarbonate

Question 27

What aspects are important for follow-up with an acute stone episode?

Answer 27

Home with PO analgesia (regular paracetamol and NSAID with opioid for breakthrough) Strain urine to check for stone passage Arrange follow-up imaging (KUB if previously visible on plain film) Early follow-up (1-2/52)

Question 28

What are the goals of early follow-up for stones?

Answer 28

Monitor stone for progression Look for evidence of persisting obstruction Return to ED if recurrent pain

Question 29

What 5 steps can be taken to prevent stone recurrence?

Answer 29

``` Adequate fluid intake Dietary modification Urinary alkalinisation Medical therapy (e.g. allopurinol, thiazide diuretics) Address cystinuria ```

Question 30

List some causes of urological haematuria

Answer 30

Period (cyclical haematuria) Prostate (prostatitis, prostate cancer, BPH) Obstructive uropathy Nephritis (IgA, interstitial) Trauma Tumour (renal, urothelial, prostate cancer, urethral) TB Thrombosis (renal infarct, renal vein thrombosis) Haematological (anticoagulation, bleeding diathesis, sickle cell) Infection/inflammation (radiation cystitis, cyclophosphamide, interstitial cystitis) Stones

Question 31

List some drugs which can cause "red" urine

Answer 31

``` Pyridium Nitrofurantoin Ripampin Ibuprofen Phenytoin L-DOPA Chloroquine Beetroot ```

Question 32

What can cause a false positive for haematuria on dipstick testing?

Answer 32

Myoglobinuria

Question 33

What % of patients presenting with gross haematuria have a urological malignancy?

Answer 33

10-20%

Question 34

When can haematuria cause sufficient blood loss to result in haemodynamic instability?

Answer 34

Post-op/trauma Radiation or chemical cystitis Anti-coagulated

Question 35

For what % of patients presenting with gross haematuria have no cause identified?

Answer 35

10-20%

Question 36

What factors of the history are important to elicit in a patient presenting with haematuria?

Answer 36

``` Initial/total/terminal? Able to pass urine? Any clots? Painful or painless? Infective symptoms? LUTS? Trauma? Recent surgery? Anticoagulation? PHx of urological conditions (RT, cancer, stones), smoking, DM, anticoagulation ```

Question 37

What features on examination are important to assess in a patient presenting with haematuria?

Answer 37

Vitals: PR/BP/temp Abdo (masses, tenderness, palpable bladder) Genital (urethral tumour) DRE

Question 38

What work-up should be performed for a patient presenting with haematuria?

Answer 38

``` FBE (Hb) Clotting profile UEC MSU/CSU with MCS CT-IVP (gold standard; U/S if low risk) Cystoscopy (at some stage) Other tests to consider: urine cytology, PSA, analysis for "active" urine (red/white cell casts, proteinuria) ```

Question 39

How should a patient with haematuria be managed?

Answer 39

Admission 3-way IDC (22 or 24F) if significant bleeding with clots or retention Manual bladder washout (>2-3L) Continuous bladder irrigation (stop new clots forming, NOT to washout pre-formed clots) Stop anticoagulants if safe to do so ?transfusion need Referral to urology