Renal Stones Flashcards Preview

Renal, Urinary and Bladder > Renal Stones > Flashcards

Flashcards in Renal Stones Deck (39):
1

Epidemiology of stone disease?

3M:1F
Peak incidence 30-50y

2

Risk of recurrence of renal stones at 1/5/lifetime?

10% recurrence at 1 year; 50% recurrence at 5 years; 60-80% lifetime risk.

3

Hereditary RFx for renal stones?

RTA, G6PD, cytinuria, xanthinuria, oxaluria.

4

Lifestyle RFx for renal stones?

minimal fluid intake; excess vitamin c, oxalate, purines, calcium, animal protein ++

5

Medications RFx for renal stones?

Loop diuretics (frusemide); acetzolamide, topiramate, zonisamide.

6

Medical conditions RFx for renal stones?

UTI (with urea-splitting organisms); myeloproliferative disorders, IBD, gout, DM, hypercalcaemia disorders, sarcoidosis, obesity (>30).

7

What causes pain in renal stones?

Urinary obstruction -> upstream distension -> pain.
-Flank pain from renal capsular distension (non-colicky)
-Severe waxing and waning pain radiating from flank to groin/testis/tip of penis due to stretching or collecting system or ureter (ureteral colic).

8

CFx of renal stones?

Storage and voiding LUTS; terminal haematuria; suprapubic pain.
-N/V
-Diaphoresis
-Tachycardia/tachypnoea
-+/- trigonal irritation (F, U)

9

GU Ddx of renal colic?

-Pyelonephritis
-Ureteral obstruction of other cause (UPJ obstruction, clot colic 2" to gross haematuria)
-Gynaec: ectopic pregnancy, ovarian cyst torsion/rupture, PID.
-Testicular torsion

10

Abdominal Ddx of renal colic?

-AAA
-Bowel ischaemia
-Pancreatitis
-Other acute abdomen

11

Neurological Ddx of renal colic?

-Radiculitis (L1): herpes zoster, nerve root compression.

12

What are the narrow points for upper tract stones?

-UPJ
-Pelvic brim
-Under Vas deferens/ broad ligament
-UVJ

13

Outline the features in pathogenesis of renal stones.

-Supersaturation of stone constituents
-Stasis, low flow and low volume (dehydration)
-Crystal formation and stone nidus
-Loss of inhibitory factors

14

Which factors inhibit stone formation?

-Citrate (forms soluble complex with calcium)
-Magnesium (forms soluble compound with oxalate)
-pyrophosphate
-Tamm-Horsfall glycoprotein

15

Indications for hospital admission in renal stones?

-Intractable pain / vomiting
-Fever
-Compromisesd renal fxn (single kidney, bilateral obstruction)
-Pregnancy

16

How should septic patients with stones be managed?

Urgent decompression via ureteric stent or percutaneous nephrostomy.
Delay definitive Rx until clearance of infection.

17

Ix in renal stones?

-FBE
-UEC
-Serum calcium and uric acid
-MSU
-Xray KUB
-CT KUB (or CT IVP)

18

Acute medical management of renal stones?

-Analgesis +/- antiemetic
-NSAIDs
-Medical explulsion therapy
-IV fluids (if vomiting)

19

Why are NSAIDs used in renal stones in acute medical management?

Pain
Help lower intra-ureteral pressure

20

What is medical expulsion therapy?

-alpha blockers (increase rate of spontaneous passage in distal ureteral stones)
-CCBs

21

Indications for interventional management of renal stones?

-Infection / sepsis
-Renal impairment
-Bilateral obstruction
-Solitary kidney
-Inability to control Sx
-Prolonged obstruction
-Spontaneous passage unlikely

22

Interventional options for management of renal stones?

-JJ stent and delayed management
-Ureteroscopy and lithotripsy
-Shock wave lithotripsy
-Percutaneous nephrostomy

23

What is first line treatment for ureteral stones >10mm?

Extracorporeal shock wave lithotripsy (ESWL)

24

Dietary modifications for prevention of renal stones?

-Increased fluid (>2L/day), K+ intake
-reduce animal protein, oxalate, Na+, sucrose, fructose intake
-avoid high dose vitamin C supplements

25

Medication alterations for prevention of renal stones?

-Thiazide diuretics for hypercalciuria
-Allopurinol for hyperuricosuria
-Potassium citrate for hypocitraturia, hypyeruricosuria

26

Features of calcium stones?

-Radioopaque on KUB
-Reducing dietary Ca2+ NOT an effective prevention method

27

Treatment of calcium stones

-Increase fluids >2L/d
Calcium stones: Cellulose phosphate, orthophosphate for absorptive causes
Calcium oxalate: thiazides, +/- potassium citrate +/- allopurinol.
Calcium struvite: ABx (must remove stone)

28

Aetiology of uric acid stones?

Uric acid precipitates in low volume, acidic urine with a high uric acid concentration.

29

Key features of uric acid stones on imaging?

-Radiolucent on KUB
-Radioopaque on CT

30

Treatment of uric acid stones?

-Increased fluid intake
-Akalinisation of urine to pH 6.5-7 (bicarb, potassium citrate)
-+/- allopurinol (if serum uric acid levels elevated)

31

Aetiology of struvite stones?

-Infection with urea splitting organisms (e.g. proteus, pseudomonas)
-Produces alkaline urinary pH and precipitation of struvite (magnesium ammonium phosphate)

32

Hx features to elicit in renal colic?

-Pain characteristics
-?Previous episodes and outcomes
-Complicating factors: pregnancy, renal impairment
-FHx

33

What proportion of renal stones are radiopaque?

90%

34

Common cause of obstructive pylonephrosis?

Usually GNB (E.Coli)

35

Management of obstructive pyelonephrosis?

-IV Abx (G-ve and enterococcus coverage)
-Urgent decompression (nephrostomy, JJ stent)
-Supportive (fluids, monitoring, +/- ICU/HDU)

36

What does spontaneous passage of renal stone depend on?

-Max size in transverse plane
-Location
-PHx of stone passage

37

Explain physiology of medical expulsive therapy?

-Ureter wall contain a1 R that mediating SM contraction
-a-blockers relax ureteric wall
-stone pass inc by 30%

38

Medical expulsive therapy dose?

Tamsulosin 0.4mg OD x 2/52

39

Follow up of renal stones?

-Home with analgesia
-Stain urine
-F/u imaging (XKUB if visible on Xray)