Brainscape's Knowledge GenomeTM

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


See full index

Genitourinary > Renal stones (Nephrolithiasis) > Flashcards

Renal stones (Nephrolithiasis) Flashcards

1
Q

What are renal stones (calculi)?

A

Renal stones (calculi) consist of crystal aggregates, stones form in collecting ducts and may be deposited anywhere from the renal pelvis to the urethra.

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

What type of kidney stone is the most common one?

A

Calcium oxalate stones.

Found in acidic urine.

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

Give 3 places where urinary tract stones are likely to get stuck.

A
  1. Ureteropelvic junction.
  2. Pelvic brim.
  3. Vesoureteric junction.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Give 5 causes of kidney stones in the upper urinary tract.

A
  1. Anatomical or congenital abnormalities that predispose to stone formation e.g. duplex, obstruction or trauma
  2. Chemical composition of urine that favours stone crystallisation
  3. Dehydration (resulting in a concentrated urine - seen particularly in those working in hot climate)
  4. Infection
  5. Hypercalcaemia, hyperoxaluria, hypercalciuria, hyperuricaemia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe the pathophysiology of stone formation in the upper urinary tract.

A

Stones form from crystals in supersaturated urine.
- 80% are calcium based e.g. calcium oxalate.

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

Describe the epidemiology of stones in the urinary tract.

A
  • 10-15% lifetime risk.
  • Males > females - 2:1 ratio.
  • Common among 30-50 y/o.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Give 3 risk factors for developing kidney stones.

A
  1. Metastable urine
  2. High calcium / oxalate / urate / cysteine
  3. High PTH – high calcium
  4. Dehydration
  5. Dents disease – high cysteine
  6. Anatomical abnormality e.g. horseshoe kidney, trauma
  7. Renal tubule acidosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the 4 types of kidney stones?

A
  1. Calcium stones - either calcium oxalate or calcium phosphate
  2. Uric acid stones
  3. Struvite stones (infection-induced)
  4. Cystine stones
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are struvite stones made from?

A

Composed of magnesium ammonium phosphate as well as calcium

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

What are struvite stones associated with?

How do they form?

A

Associated with infection.

Usually due to UTI with organism such as Proteus mirabilis.

Bacteria hydrolyses urea + makes ammonium hydroxide
= Increased ammonium ions
= Alkaline urine
= Precipitation of magnesium + phosphate

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

How are cysteine stones formed?

A
  1. Caused by cystinuria - a autosomal recessive condition affecting cysteine (amino acid) in epithelial cells of renal tubules and GI tract
  2. Resulting in excessive urinary excretion and formation of cysteine stones
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Give 5 symptoms of upper urinary tract kidney stones.

A
  1. Loin pain -> groin pain.
  2. ‘Renal colic’ - pain caused by a blockage in the urinary tract.
  3. UTI symptoms e.g. dysuria, urgency, frequency.
  4. Recurrent UTI’s.
  5. Haematuria.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is kidney stone pain like?

A
  • Severe
  • Unilateral
  • Loin to groin
  • Colicky
  • Sudden onset
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Apart from pain, 3 other features of kidney stones?

A
  • Urgency
  • Frequency
  • Writhing
  • Frank or microscopic haematuria
  • N + V
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Investigations for kidney stones.

A
  1. Focused history and examination:
    * Vitamin D consumption - hypercalcaemia, recurrent UTIs, lots of rhubarb/ tea (high in oxalate)
  2. Urine dipstick:
    * Usually positive for blood - haematuria
    * Also looks for red cells, protein and glucose
  3. Mid-stream-specimen of urine sent for microbiology culture and sensitivity
  4. Bloods:
    * Serum urea, electrolyte, creatinine and calcium
    * FBC
    • KUBXR - Kidney Ureter Bladder X-ray:
      * FIRST LINE INVESTIGATION
      * 80 % sensitive
      * See stone in line of renal tract
  6. NCCT-KUB - Non-contrast Computerised Tomography:
    * GOLD STANDARD
    * Very rapid
    * 99% sensitive for stones - DIAGNOSTIC
    * No contrast so no renal damage or allergy
    * But no functional info and gives radiation dose equivalent to 18 months background radiation
  7. Ultrasound:
    * Shows kidney stones and renal pelvis dilatation well but ureteric stones can be missed
    * Sensitive for hydronephrosis
    * Very poor at visualising stones in ureter
    * Useful in pregnant and younger recurrent stone-formers (no radiation risk)
    * Rarely used ACUTELY
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Which stones can/can’t be seen on X-ray?

A

Uric acid and cysteine stones are radiolucent (can’t see)
Calcium and struvite stones can be seen

17
Q

What is the gold standard investigation for kidney stones?

A

NCCT-KUB - Non-contrast Computerised Tomography

18
Q

What would you see on a non-contrast CT scan for kidney stones?

A

CT kidneys, ureter, bladder - without contrast:

  1. Stone is bright white
  2. Fat stranding in perinephric tissues.
  3. Inflammation.
  4. Hydronephrosis (one or both kidneys become stretched and swollen as the result of a build-up of urine inside them)
  5. Cortical thickening.
19
Q

Describe the treatment options for urinary stones.

A
  1. Conservative e.g. if stone is <5mm and in a safe location or if the patient is asymptomatic or co-morbid.
  2. Medical e.g. nifedipine.
  3. Lithotripsy - fragment stones which will then pass spontaneously.
  4. Surgical e.g. ureteroscopic; PCNL for larger ‘stag horn’ stones; nephrectomy.
20
Q

Describe the conservative management for kidney stones.

A
  1. Strong analgesic for renal colic
    e.g. NSAIDs - IM diclofenac
  2. Antibiotics if infection e.g. IV CEFUROXIME or IV GENTAMICIN:
    * To prevent pyonephrosis (combination of infection and obstruction):
    - Can lose renal function in 24 hours
    - Systemic sepsis leading to septic shock
  3. Antiemetics to prevent vomiting
    e.g. metoclopramide, prochlorperazine or cyclizine
  4. Watchful waiting - Observe for sepsis
21
Q

Describe the medical expulsive therapy for kidney stones.

A

For stones larger than 5mm with pain and not resolving.

Oral Nifedipine
OR
Alpha-blocker e.g. Oral Tamsulosin

  • Can promote expulsion and reduce analgesia requirements
22
Q

What CCB can be used to treat renal stones?

A

Nifedipine.

23
Q

What is the best analgesia for acute kidney stones?

A

IV Paracetamol or IM diclofenac

24
Q

3 surgical managements for kidney/ureter stones.

A
  1. Extracorporeal shockwave lithotripsy (ESWL)
    - Ultrasound fragments stone
  2. Endoscopy (uteroscopy) with YAG
    - Laser for larger stones
  3. Percutaneous nephrolithotomy (PCNL)
    - Keyhole surgery to remove stones that are large, multiple or complex
25
Q

treatment for cysteine stones?

A

captopril (cysteine binder)

26
Q

Give 5 general ways in which urinary tract stones can be prevented.

A
  1. Stay well hydrated.
  2. Low salt diet and normal/low Ca2+ dietary intake
  3. Healthy protein intake.
  4. Reduced BMI.
  5. Active lifestyle
27
Q

Give a method of prevention of recurring uric acid stones.

A

Deacidification of urine
e.g. ORAL SODIUM BICARBONATE to alkalinise urine

Since they only form in acidic urine.

28
Q

Give a method of prevention of recurring cysteine stones.

A

Cystein binders e.g. Captopril

Genitourinary (17 decks)

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