Brainscape's Knowledge GenomeTM

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


See full index

Renal > Urolithiasis > Flashcards

Urolithiasis Flashcards

1
Q

What are crystals?

A

Microscopic

  • do not cause clinical signs
  • can have crystals without stones and vice versa
  • can have stones and crystals of different types (though usually the same)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which type of crystal is common in cats?

A

Struvite (esp if left sitting or in fridge)

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

How are urolithis described?

A

Mineral component
Location
> Tx. Depends on these

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

How do urolithis form?

A
  • urine super saturated
  • concentration of solute required to start the process (nucleation) generally higher than that required for growth
  • if concentration decreased sufficiently then crystals dissolve
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Is Calcium oxalate commonly excreted in urine?

A
  • all carnivores and omnivores excrete excessive calcium oxalate than can be dissolved in an equivalent volume of water
  • needs other binders to ensure it dissolves (eg. citrate)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is seen in history and PE with neophroliths and ureteroliths?

A
  • asymptomatic
  • pyelonephritis
  • renal failure (if bilateral obstruction or infection)
  • renal colic? Rarely picked up
    > PE often Normal
  • hydro nephrosis/irregular kidneys
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Hx and PE with cystoliths?

A
  • dysuria, pollakiuria, haematuria
  • inapropriate urination
  • generally not palpable
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Hx and PE with urethroliths?

A
  • abdo discomfort
  • poor/no urine stream
  • licking genitals
  • obstruction and post renal azoteamia
  • enlarged painful bladder, urethroliths may be palpable per rectum/base of os penis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How can urolithis be diagnosed?

A 
> plain film 
- if radiopaque stones 
> contrast
- excretory urogram for nephroliths, urethroliths
- double contrast for bladder
- retrograde for urethral 
> ultrasound
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How can urolith type be predicted?

A
  • signalment
  • radiopaque or lucent
  • ph
  • Hx of stone type (will not always be the same type)
  • UTI with struvite
  • disease association
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How should uroliths be analysed?

A
  • NOT CHEMICAL TEST AT USUAL LAB!
  • food companies may do for free (Royal can in)
  • need X-ray diffraction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

General Tx options for renal and ureteral stones?

A
  • surgical (difficult, treaumatic)
  • urinary bypass
  • lithotripsy(not available UK but owners may ask)
  • dietary dissolution (if non obstructed, often calcium oxalate not available to dissolution)
  • benign neglect if not infected or causing a blockage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

General Tx options for bladder stones?

A
  • medical dissolution
  • voiding urohydropropulsion
  • surgery (cystotomy)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

General Tx options for urethral stones?

A
  • retrograde flush into bladder

- surgery (urethrotomy, urethrostomy)

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

When is medical management indicated?

A
  • no obstruction
  • no contraindications to dietary therapy
  • urolith composition amenable to dissolution (struvite, cystine, urate)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is medical management of stones?

A
  • v concentration of urine
  • decrease quantity of calculigenic crystalloids by diet or drug tx
  • increase solubility of salts by changing ph (diet)
  • Tx predisposing cause
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is urohydropulsion? Contra indication?

A
  • fill bladder with saline
  • position so urethra vertical
  • agitate
  • allow stones to settle
  • initiate voiding
  • continue pressure to keep brisk urine flow
  • 3d Abx
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is struvite associated with in dogs and cats?

A
  • UTIs in dogs

- form I sterile urine in cats

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

When do struvite crystals form? What are struvite made of?

A

> magnesium ammonium phosphate/ triple phosphate
DOGS
- UTI with urease producing bacteria (staph, proteus) -> production of ammonia + bicarb from urea
- pH ^
- mostly female
CATS
- often sterile

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

Tx struvite?

A 
> Tx UTI for 3-4w after radiographic resolution 
> reduce urinary Mg, ammonium, phosphate
> maintain pH  ^ water intake 
> monitor progress 
- rads (size/density/number)
- urinalysis (pH 6-6.5, USG
21
Q

How radio opaque are struvite stones?

A
  • Radiopaque
  • Big
  • pyramidal shape
22
Q

Prevention of struvite formation?

A
  • Hills and royal canin available
  • long term preventative tx, not recommended for dogs unless sterile stones present
  • monoitor for recurrence of UTIs
  • diets designed to prevent struvite recurrence may -> calcium oxalate stone formation and are not necessary
23
Q

How has calcium oxalate incidence changed?

A
  • increased incidence especially in cats

- thought d/t inappropriate use of acidifying diets to prevent struvite!

24
Q

Predispositions for calcium oxalate?

A 
> breed
- terriers, poodles, shnauzer
- burmese, himalayan, persian
> more males than females
> older
> upper urinary tract common
25
Q

Appearance of calcium oxalate?

A
  • radiopaque

- spiky

26
Q

Tx calcium oxalate?

A
  • NOT medical!
  • need surgery or urohydropulsion
  • can ignore
27
Q

Do calcium oxalate stones often recur?

A

60% recurrence within 3 years

28
Q

Prevention of calcium oxalate stones?

A
  • increase water intake (dogs will eat soup!)
  • sodium supplementation
  • neutral/marginal alkaline urine pH
    > but solubility of calcium oxalate not pH dependent
    > more acidifying diet promotes calcium excretion
29
Q

What is laser lithiotripsy

A
  • break up stone so can be removed by urohydropulsion
  • guided by cystoscopy
  • energy absorbed by water so only affects 1-2mm
30
Q

Which dogs are predisposed to Ammonium urate stones?

A 
> dalmations,  bulldogs and other breeds
- genetic test for at risk breeds 
> hepatic dysfunction 
- PSS
- ^ excretion ammonia and urea
31
Q

How common are Ammonium urate stones?

A
  • 8% stones
32
Q

Why are Dalmatians PDF urate stones?

A

Lack transporter of Uric acid into hepatocytes (not enzyme as commonly stated)

33
Q

Tx ammonium urate?

A
  • tx underlying liver dz or PSS
  • in other cases, dissolution is possible
  • Treat UTIs
  • reduce purines, neutral -> alkali pH (Hills U/D good)
  • Allopurinol competitively inhibits xanthine oxidase -> v uric acis
  • this can result in xanthine stones if protein not restricted
34
Q

Prevention of urate stones?

A
  • feed low protein diet

- alkalinsing diet

35
Q

What causes Cystine stones? How common are these? How can they be dx?

A
  • 3% canine stones from UK (breed pdf)
  • renal tubular defect -> excess cystine (poorly soluble)
  • seen in middle aged dogs despite being CONGENITAL problem
  • radioLUCENT so need ultrasound
  • medical tx effective but too expensive
36
Q

Why does cystine Tx often fail?

A

Will recur, medical tx prohibitively expensive, multiple surgeries needed so usually PTS

37
Q

Newly discovered method of Tx for cystine?

A

Castration decreases cystine excretion

38
Q

When are Calcium phosohate stones seen?

A
  • 1* hyperparathyroidism
  • as part of a mixed urolith
  • d/t mineralization / a blood clot
39
Q

When are Calcium carbonate stones seen?

A
  • most common in rabbits and horses

- high [Ca] in urine

40
Q

When are Silica stones seen?

A
  • GSD pdf
  • associated with poor diet
  • rare
41
Q

Indications for surgery in smallies?

A
  • obstruction
  • Unknown or unpredictable urolith composition
  • failure medical Tx
  • presence of other UT abnormalities
  • immature dogs
  • owner preference
  • cost
42
Q

2 main surgical options?

A 
> open viscus and removing 
 -otomy
- nephro 
- pyelo
- uretero
- cysto
- urethro
> provide urine diversion 
- -ostomy
- usually permenant 
- urethrostomy
> minimally invasive 
- specialist places only
43
Q

What needs to be done prior to surgery?

A
  • stabilise hyperkalaemia and severe azotaemia
  • ensure number and location of calculi known immediately before surfery
  • place in dwelling urinary catheter (extension set) and empty bladder
44
Q

What must be done at end of surgery?

A
  • check all calculi / fragments removed

- submit calculi for quantitative analysis

45
Q

What are Halsteads principles of surgery

A
  • gentle tissue handling
  • accurate heamostasis
  • preservation of adequate blood supply
  • aseptic technique
  • no tension on tissues
  • careful tissue approximation
  • obliteration of dead space
46
Q

Outline cystotmy procedure

A
  • catheter pre-surgical
  • caudal midline ventral celiotomy, care entering peritoneal cavity
  • locate bladder and empty if necessary
  • stay suture (prolene) in Apex
  • pack off abdominal cavity
  • ventral midline cystotomy
  • further stay sutures
  • lots of blood! Need suction or cautery
  • remove obvious calculi
  • flush urethra with sterile saline(non sterile assistant) until all calculi removed
  • close bladder with synthetic absorbable (eg. Poliglecaprone 25 MONOCRYL) doesn’t need to last long, heals quickly
  • single or double layer
  • appositional or inverting (never everting)
  • try and avoid suture material in lumen of bladder
47
Q

Post op care following cystotomy?

A
  • Indwelling Catheter not used
  • IVFT 12-24hours to prevent clot from Haematuria (can obstruct!)
  • allow to urinate frequently
  • analgesia
  • medical, management depending on stone type
48
Q

Commonest risks/complications with cystotomy?

A
  • not removing all calculi
  • dehiscence -> urileritoneum
  • blood clot
  • cystitis
49
Q

What are urolithis? Other names?

A

Calculi, stones, urolithis - macroscopic

Renal (23 decks)

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