[2] Urinary Tract Stones Flashcards
(82 cards)
1
Q
What are urinary tract stones also known as?
A
Urolithiasis
2
Q
What is urolithiasis?
A
When a solid piece of material occurs in the kidney tract
3
Q
Where do urinary tract stones form?
A
Typically in the kidney
4
Q
How to urinary tract stones typically leave the body?
A
In the urine stream
5
Q
When can kidney stones pass in the urine stream without causing symptoms?
A
When it is small (under 5mm)
6
Q
What may happen when a stone is bigger than 5mm?
A
It can cause blockage of the ureter resulting in severe pain and other symptoms
7
Q
When are renal calculi formed?
A
When the urine is supersaturated with salt and minerals.
The other factor that leads to stone production is the formation of Randall’s plaque
8
Q
What salt and minerals might the urine become supersaturated with?
A
- Calcium oxalate
- Struvite
- Uric acid
- Cysteine
9
Q
What causes Randall’s plaques?
A
The precipitation of calcium oxalate in the basement membrane of the thin loops of Henle, which eventually accumulate in the subepithelial space on renal papillae
10
Q
What does the formation of Randall’s plaques eventually lead to?
A
The formation of a calculus
11
Q
What % of urinary tract stones are bladder stones?
A
Around 5%
12
Q
What do bladder stones usually occur due to?
A
- Foreign bodies
- Obstruction
- Infection
13
Q
What is the most common cause of bladder stones?
A
Urinary stasis due to failure of emptying the bladder completely on urination
14
Q
Which gender do bladder stones occur most commonly in?
A
Men (95% of cases)
15
Q
What are bladder stones in women usually associated with?
A
- Sutures
- Synthetic tapes or meshes
- Urinary stasis
16
Q
What are the risk factors for urinary tract stones?
A
- Anatomical anomalities in kidneys and/or urinary tract
- Family history of stones
- Hypertension
- Gout
- Hyperparathyroidism
- Immobilisation
- Relative dehydration
- Metabolic disorders that cause an increased excretion of solute
- Deficiency of citrate in urine
- Cystinuria
- Drugs
17
Q
What anatomical abnormalities in the kidneys and/or urinary tract increase the risk of urinary tract stones?
A
- Horseshoe kidney
- Urethral stricture
18
Q
What metabolic disorders cause an increased excretion of solute?
A
- Chronic metabolic acidosis
- Hypercalciuria
- Hyperuricosuria
19
Q
What drugs can increase the risk of urinary tract stones?
A
- Diuretics such as triamterene
- Calcium/vitamin D supplements
20
Q
How are most urinary tract stones discovered?
A
During investigations for other conditions, as many are asymptomatic
21
Q
What is the classic symptom of urinary colic?
A
Sudden severe pain
22
Q
What causes the pain in urinary tract stones?
A
Stones in the kidney, renal pelvis, or ureter, which causes dilation, stretching, and spasm of the ureter
23
Q
Other than pain, what symptoms may be present with urinary tract stones?
A
- Rigors and fever
- Dysuria
- Haematuria
- Urinary retention
- Nausea and vomiting
24
Q
Where does the pain in renal colic start?
A
In the loin, at about the level of the costovertebral angle
25
Where does the pain in renal colic move too?
Moves to the groin, with tenderness of the loin or renal angle
26
When do urinary tract stones cause pain in the loin?
When the stone is high and distends the renal capsule
27
When do urinary stones cause pain in the flank?
As it moves anteriorly and down the urinary system
28
What is more painful, a stone that is moving or a stone that is static?
A stone that is moving
29
Where might renal colic pain radiate?
* Testis
* Scrotum
* Labia
* Anterior thigh
30
Describe the pattern of pain in renal colic?
It is fairly constant, but there are often periods of relief, or just a dull ache before it returns
31
How will a patient with renal colic appear from the end of the bed?
They will be writing around in agony, *in contrast to a patient with peritoneal irritation who lies still*
32
When will a renal colic patient be apyrexical?
When it is uncomplicated
33
What might abdominal examination reveal with renal colic?
Sometimes reveals tenderness over affected loin, and bowel sounds may be reduced
34
Why is full and thorough abdominal examination required in renal colic?
To check for other possible diagnoses
35
What do the differential diagnoses of urinary tract stones depend on?
The position of the pain, and the presence or absence of pyrexia
36
What are the differential diagnoses of urinary tract stones?
* Biliary colic
* Dissected aortic aneurysm
* Pyelonephritis
* Acute pancreatitis
* Acute appendicitis
* Perforated peptic ulcer
* Epididymo-orchitis or testicular torsion
37
What investigations are done into urinary tract stones?
* Urine testing
* Blood tests
* CT scanning
* Ultrasound scanning
* Plain x-rays of the kidney, ureter, and bladder
* Stone analysis
38
What is the imaging modality of choice for urinary tract stones?
CT scanning
39
Why may ultrasound scanning be useful in urinary tract stones?
It may be helpful to differentiate radio-opaque from radiolucent stones, and in detecting evidence of obstruction
40
What can plain x-rays of kidney, ureter, and bladder be useful for in urinary tract stones?
Watching the passage of radio-opaque stones
41
What should urine testing involve in urinary tract stoens?
* Stick testing
* Midstream specimen of urine for MCS
42
What are red cells suggestive of when urine testing for suspected urinary tract stones?
Urolithiasis
43
What are white cells and nitrates suggestive of on urine stick testing?
Infection
44
What does a pH above 7 suggest on urine stick testing?
Urea-splitting organisms such as Proteus
45
What does a pH below 5 suggest on urine stick testing?
Uric acid stones
46
What blood tests should be done in urinary tract stones?
* FBC
* CRP
* Renal function
* Electrolytes
* Calcium
* Phosphate and urate
* Creatinine
47
What are the indications for stone analysis?
* All first-line stone formers
* All patients with recurrent stones who are on pharmacological preventing therapy
* Late recurrence after long stone-free period
48
Where can the initial management of urinary tract stones take place?
As an inpatient or urgent outpatient basis, *depending on how easily the pain can be controlled*
49
What are the indications for hospital admission with urinary tract stones?
* Fever
* Solitary kidney or known non-functioning kidney
* Inadequate pain relief or persistent pain
* Inability to take fluids due to nausea and vomiting
* Anuria
* Pregnancy
* Poor social support
* People over the age of 60 years, if there are concerns on clinical condition or diagnostic uncertainty
50
What are the indications for urgent outpatient appointment with urinary tract stones?
* Pain has been relieved
* Patient able to drink large volumes of fluid
* Adequate social circumstances
* No complications evident
51
What should be offered first line for the relief of renal colic pain?
NSAIDs, usually in the form of diclofenac IM or PR
52
Why are NSAIDs first line in managing renal colic pain?
Because they are more effective than opioids for this indication, and have less tendency to cause nausea
53
What is the use of parenteral morphine in the management of renal colic pain?
Parenteral morphine is required in severe renal colic pain, as it works quickly and provides pain relief in the time taken for an NSAID to work
54
What opioid should not be used in the management of urinary tract stones?
Pethidine
55
What therapies should be used in addition to pain relief when required?
* Anti-emetics
* Rehydration
56
What happens to the majority of stones?
They pass spontaneously
57
How long do stones take to pass spontaneously?
1-3 weeks
58
How often should the progress of a urinary tract stone be monitored?
At a minimum of weekly intervals
59
Which patients should have monitoring of their stone progress?
Those who have not passed the stone, or have continuing symptoms
60
How long can conservative management of urinary tract stones be continued for?
Up to 3 weeks, unless the patient is unable to manage the pain, or if they develop signs of infection or obstruction
61
What is medical expulsive therapy?
A therapy used to facilitate the passage of a stone, using calcium-channel blockers or alpha-blockers
62
When is medical expulsive therapy useful in urinary tract stones?
In cases where there are no obvious reasons for immediate surgical removal
63
How should patients with urinary tract stones be managed at home?
Should drink lots of fluids, and if possible void urine into a container or through a strainer to catch any identifiable calculus
Paracetamol can be used for mild to moderate pain. Codeine can be added if more pain relief is required
64
What % of kidney stones will not pass spontaneously?
1/5
65
How are urinary tract stones managed surgicall when the ureter is blocked, or could potentially become blocked?
A stent is inserted using a cystoscope
66
Describe a urinary tract stent
It is a thin, hollow tube with both ends coiled
67
What is the purpose of a urinary tract stent?
It is used as a temporary holding measure, as it prevents the ureter from contracting and thus reduces pain, buying time until a more definitive measure can be taken
68
What surgical procedures can be used to remove stones?
* Extracorporeal shock wave lithotripsy (ESWL)
* Percutaneous nephrolithotomy
* Ureteroscopy
* Open surgery
69
What happens in extracorporeal shock wave lithotripsy?
Shock waves are directed over the stone to break it apart, and the stone particles will then pass spontaneously
70
What is percutaneous nephrolithotomy used for?
* Larger stones (\>2cm)
* Staghorn calculi
* Cysteine stones
71
What happens in a percutaneous nephrolithotomy?
Stones are removed using a nephroscope
72
What is a ureteroscopy?
Using a laser to break up the stone
73
When is open surgery used in urinary tract stones?
Rarely necessary, usually reserved for complicated cases or those in whom all the other surgical options have failed, e.g. multiple stones
74
What is the advantage of a percutaneous surgical approach in the management of bladder stones?
It has a lower morbidity, with similar results to transurethral surgery
75
Who is ESWL reserved for in the management of bladder stones?
Patients with high surgical risks
76
Why is ESWL reserved for patients with high surgical risks in the management of bladder stones?
Because it has a lower rate of elimination of stones
77
What are the complications of urinary tract stones?
* Complete blockage of urinary flow from kidney
* Infection and sepsis
* Pyelonephritis
78
What can happen if a complete blockage of urinary flow from the kidney persists for more than 48 hours?
May cause irreversible renal damage
79
Is recurrence of renal stones common?
Yes
80
What is the result of the recurrence of urinary stones being common?
Patietns who have had a renal stone should be advised to adopt several lifestyle measures to prevent or delay recurrence
81
What lifestyle changes should be advised to prevent the recurrence of urinary stones?
* Increase fluid intake
* Reduce salt intake
* Reduce amount of meat and animal protein eaten
* Reduce oxalate intake, e.g. chocolate, nuts
* Drink regular cranberry juice
* Maintain calcium intake at normal levels
* Medications can sometimes be given to prevent further stone formation
82
What medications can be given to prevent further stone formation?
* Thiazide diuretics
* Allopurinol
* Calcium citrate
