Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

METABOLIC > UROLOGY - STONES > Flashcards

UROLOGY - STONES Flashcards

1
Q

What is nephrolithiasis?

A

Kidney stones
Aka renal calculi, urolithiasis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What’s the incidence and recurrent rate for kidney stones?

A

10% incidence in the UK population at some point in their life
50% recurrence rate in 10 years

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Where do kidney stones form and where are they most likely to get stuck?

A

Form in the renal pelvis
Likely to get stuck in the vesicoureteric junction but can get stuck anywhere!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are most stones made of?

A

Calcium oxalate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What types of stones are there?

A

80% Calcium based e.g. oxalate or phosphate
Struvite
Uric acid
Cystine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

When do struvite stones tend to form?

A

In response to a urinary tract infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

When do uric acid stones tend to form?

A

Those who loose too much fluid e.g. chronic diarrhoea
Eat a high protein diet
Diabetes or metabolic syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

When do cysteine stones form?

A

In people with cystinuria (a hereditary disorder that causes the kidneys to excrete too much of the amino acid cysteine)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What’s the prevalence of renal stones in men:women?

A

2:1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the complications of kidney stones?

A

Infections due to obstructive pyelonephritis
AKI - obstruction causes back up into the kidney
Recurrent stones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How can a renal stone progress to a medical emergency?

A

If it obstructs the system and there is an infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the specific causes of renal stones?

A

Dehydration
Hypercalcaemia
Hypercalciuria
Hyperoxaluria
Hyperuricaemia
Hyperuricosuria
Infection
Primary renal disease
Drugs
Cystinuria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What’s the basic aetiology of renal stones?

A

Solute concentrations exceed saturation:

Chemical composition of urine favours stone formation
Concentrated urine from dehydration
Changes in urinary pH
Impairment of inhibitors that prevent crystallisation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are some urinary solutes?

A

Calcium
Uric acid
Oxalate
Sodium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are some stone inhibitors?

A

Citrate
Magnesium
Pyrophosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is hyperperistalsis?

A

When there is an obstruction so the ureters increase peristalsis in an attempt to move the obstruction out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the risk factors for renal stones?

A

Dehydration
Hypercalciuria, hypercalcaemia
Cystinuria
Hypocitraturia
Hyperuricosuria
High dietary oxalate
Renal tubular acidosis
PCKD or medullary sponge kidney

Urate stones:
Gout
Ileostomy (loss of HCO3- and fluid = acidic urine)
Extensive tissue breakdown e.g. maliganncy

Calcium stones:
Loop diuretics, steroids, acetazolamide, theophylline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Why is obesity a risk factor for renal stones?

A

Obesity is associated with insulin resistance and compensatory hyperinsulinemia, metabolic derangements that may lead to the formation of calcium-containing kidney stones - this is because insulin resistance may increase the amount of calcium in the urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How can a high protein diet increase the risk for kidney stones?

A

It increases the level of uric acid and can reduce levels of urinary citrate which helps prevent stones from forming

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How can a high salt diet increase the risk for kidney stones?

A

It causes you to lose more calcium in the urine as sodium and calcium share the same transport in the kidney

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How can antacids increase the risk for kidney stones?

A

They can increase the excretion of calcium in the urine and affect the pH of the urine

22
Q

How can carbonic anhydrase inhibitors increase the risk for kidney stones?

A

They increase calcium excretion and decrease citrate in the urine

23
Q

How do renal stones present?

A

May be asymptomatic
Renal colic - excruciating unilateral loin to groin, colicky pain
Move restlessly
Associated with pallor, sweating, vomiting and nausea
Associated with haematuria in 80% of cases
Reduced urine output
Sepsis symptoms if infection is present

24
Q

How do we investigate renal stones?

A

Bloods - FBC, CRP and MCP, serum calcium. EGFR, U&Es
Urine dip stick - may show haematuria (note if normal this does not exclude kidney stones!)
Abdominal x-ray (may show calcium stones)
Non-contrast CT KUB within 24 hours of presentation (for diagnosis - USS KUB can be used instead for children and pregnant women!)

25
Q

What does a renal stone on ultrasound show?

A

Acoustic shadowing

26
Q

How do we manage renal stones?

A

Analgesia with NSAIDs - diclofenac
Anti-emetics for any n+v
Antibiotics if infection is present

Watchful waiting if stone is <5mm as 50-80% chance they will pass!
Medical expulsion therapy (tamsulosin) is used to help passage of stones
Surgery if stones are >10mm, dont pass, complete obstruction or infection - extracorporeal shockwave lithotripsy, percutaneous nephrolithotomy, ureteroscopy and laser lithotripsy, open surgery

27
Q

When should you use extracorporeal shockwave lithotripsy?

A

Any renal or ureteric stones of any size

28
Q

When should you use percutaneous nephrolithotomy?

A

Renal stones larger than 20mm and consider for ureteric stones over 10mm when ureteroscopy fails

29
Q

What drugs do we use for medical expulsion therapy?

A

Alpha blockers e.g. tamsulosin

30
Q

What is percutaneous nephrolithotomy?

A

Performed in theatres under a general anaesthetic
A nephroscope is inserted via a small incision in the back, through the kidney to assess the ureter
When stones are identified tools are used to break the stones into smaller pieces and remove them
A nephrostomy tube can be left in after the procedure to allow drainage of the kidney

31
Q

What is extracorporeal shockwave lithotripsy?

A

External machine generates shock waves and directs them at stones under X-ray guidance. This breaks stones into smaller parts making them easier to pass

32
Q

What is uteroscopy and laser lithotripsy?

A

Passing a uteroscope through the urethra and bladder and up the ureter to the point where the stone is located
They can then break the stone up using targeted lasers - easier to pass

33
Q

How do you conservatively prevent recurrence of renal stones?

A

Advise patient to drink up to 3L water a day, fresh lemon juice, avoid carbonated drinks, low salt intake <6g a day, normal calcium intake in diet, limit dietary protein intake
Reduce oxalate rich foods for calcium stones (spinach, beetroot, nuts, rhubarb and black tea)
Reduce intake of purine rich foods for uric acid stones (liver, kidney, anchovies, sardines and spinach)

34
Q

What’s the analgesia of choice for renal colic?

A

NSAID

35
Q

How can calcium renal stones be prevented?

A

High fluid intake
Low animal protein
Low salt diet
Thiazide diretics as they increase distal tubular calcium resorption

36
Q

How can oxalate renal stones be prevented?

A

Cholestyramine or pyridoxine to reduce urinary oxalate secretion

37
Q

How can uric acid renal stones be prevented?

A

Allopurinol
Urinary alkalinization e.g. oral bicarbonate

38
Q

Which kidney stones are not visible on x-ray?

A

Uric acid stones
Xanthine stones

39
Q

What is a stag horn calculus? Which stones is this moist likely with?

A

When the stone forms the shape of the renal pelvis i.e. horns extend into renal calyces
Most commonly associated with stones made of struvite

40
Q

What is struvite?

A

Some bacteria produce urease which catalyses the hydrolysis of urea to ammonia and CO2 = raises pH of urine making it more alkaline = magnesium and phosphate ions combine with ammonium ions to form struvite crystals

41
Q

What medications can be used to prevent recurrent of calcium stones?

A

Potassium citrate
Thiazide diuretics

42
Q

What medications can be used to prevent recurrent of oxalate stones?

A

Cholestyramine
Pyridoxine

43
Q

What medications can be used to prevent recurrent of uric acid stones?

A

Allopurinol
Urinary alkanization e.g. oral bicarbonate

44
Q

Why is fresh lemon juice good for preventing recurrent kidney stones?

A

As citric acid binds to urinary calcium, reducing the formation of stones

45
Q

Why should you avoid carbonate drinks when preventing recurrent kidney stones?

A

Cola drinks contains phosphoric acid which promotes calcium oxalate formation = development of stones

46
Q

Who should you use medical expulsive therapy for?

A

Kidney stone s<10mm

47
Q

How does tamsulosin work for expulsion of the kidney stone?

A

It acts as an antagonist on alpha 1 adrenergic receptors which relaxes the smooth muscle in the ureter
This reduces urethral spasm and increases urethral diameter = helps facilitate the passage of the kidney stone

48
Q

What is homocystinuria?

A

Inherited recessive disorder of transmembrane cystine transport leading to decreased absorption of cystine from intestine and renal tubule
Multiple stones may form

49
Q

How do you treat patients with obstructive urinary calculi and signs of infection?

A

IV antibiotics and urgent renal decompression (percuatous nephrostomy done under interventional radiology)

50
Q

Whats the most common organism causing struvite stones?

A

Proteus

METABOLIC (43 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions