Urology: UTI & Urinary Retention Flashcards
1
Q
Lower UTI vs pyelonephritis?
A
Lower UTI –> nfection in the bladder, causing cystitis (inflammation of the bladder).
Pyelonephritis –> Inflammation of the kidney resulting from bacterial infection.
2
Q
What does the inflammation affect in pyelonephritis?
A
1) kidney tissue (parenchyma)
and
2) renal pelvis (where ureter joins kidney)
3
Q
Why are UTIs more common in women?
A
Shorter urethra
4
Q
What is the 1ary source of bacteria for UTIs?
A
Faeces: normal intestinal bacteria, such as E. coli, can easily journey to the urethral opening from the anus.
5
Q
What is the typical way that intestinal bacteria is spread to urethra?
A
Sexual activity is a crucial method for spreading bacteria around the perineum
6
Q
Risk factors for UTIs?
A
1) sexual activity
2) poor hygiene
3) incontinence
4) catheters
7
Q
Presentation of a lower UTI?
A
- dysuria (pain, stinging or burning when passing urine)
- increased frequency
- suprapubic pain
- urgency
- incontinence
- haematuria
- cloudy or foul smelling urine
- fever (typically low grade in lower UTI)
8
Q
How can lower UTIs often present in older and frail patients?
A
Acute confusion is commonly the only symptom in older and frail patients
9
Q
Urine dipstick vs urine culture?
A
Culture (morning sample most reliable) –> can determine the infective organism and the antibiotics that will be effective in treatment.
Dipstick –> have the advantage of being rapid and easy but less reliable
Not all patients with an uncomplicated UTI require an MSU.
10
Q
Investigations in lower UTI?
A
1) Urine dipstick
2) A midstream urine (MSU) sample: sent for microscopy, culture and sensitivity tesing
N.B. Not all patients with an uncomplicated UTI require an MSU.
11
Q
Who should urine DIPSTICKS not be used in the diagnosis of a UTI in (as less reliable)?
A
1) women >65
2) men
3) catheterised patients
12
Q
Who is an MSU important in lower UTI (9 circumstances)?
A
1) pregnant patients
2) patients with recurrent UTIs (2 episodes in 6 months or 3 in 12 months)
3) atypical symptoms
4) when symptoms are persistent or don’t improve with Abx
5) women aged >65 y/o
6) men
7) visible or non-visible haematuria
8) have a urinary catheter in situ or have recently been catheterised
9) risk factors for resistance or complicated UTI e.g. abnormalities of genitourinary tract, renal impairment, residence in a long term care facility, previous resistant UTI.
13
Q
At what age are urine dipsticks less reliable?
A
> 65
14
Q
What defines a ‘recurrent’ UTI?
A
2 episodes in 6 months or 3 in 12 months
15
Q
Management of a UTI in non-pregnant women?
A
1) nitrofurantoin or trimethoprim for 3 days
2) send a urine culture if:
- aged > 65 years
- visible or non-visible haematuria
16
Q
What is the cause of nitrites in the urine in a UTI?
A
Gram-negative bacteria (e.g., E. coli) break down nitrates (a normal waste product in urine) into nitrites.
17
Q
How are leukocytes tested for on a urine dipstick?
A
Leukocyte esterase (a product of leukocytes) is tested on a urine dipstick, indicating the number of leukocytes in the urine.
18
Q
Cause of leukocytes in the urine?
A
It is normal to have a small number of leukocytes in the urine, but a significant rise can result from an infection or other cause of inflammation.
19
Q
What do RBCs in the urine indicate?
A
Indicates bleeding and is a common sign of infection. Can also be present with other causes, such as bladder cancer or nephritis.
20
Q
Microscopic vs macroscopic haematuria?
A
1) Microscopic: where blood is seen on a urine dipstick but not seen when looking at the sample.
2) Macroscopic: where blood is visible in the urine.
21
Q
Are nitrites or leukocytes in the urine a better indicatino of infection in a UTI?
A
Nitrites
22
Q
What urine dipstick result indicates that a patient will LIKELY have a UTI?
A
Nitrites or leukocytes AND red blooc cells
23
Q
How does the presence of nitrites or leukocytes guide management in UTIs?
A
Only nitrites –> worth treating as a UTI
Only leukocytes –> a sample should be sent to the lab for further testing.
24
Q
What is the most common cause of UTIs?
A
Escherichia coli (gram-negative, anaerobic, rod-shaped bacteria)
25
Top 6 organisms causing UTIs?
1) E. coli
2) Klebsiella pneumoniae (gram-negative, anaerobic, rod-shaped bacteria)
3) Enterococcus
4) Pseudomonas aeruginosa
5) Staphylococcus saprophyticus
6) Candida albicans (fungal)
26
What are the 2 key Abx used in the management of UTIs?
1) nitrofurantoin
2) trimethoprim (often associated with high rates of bacterial resistance)
27
Who is nitrofurantoin avoided in (in non-pregnant women)?
Avoided in patients with an eGFR <45
28
What are 3 alternatives to nitrofurantoin & trimethoprim in UTIs?
1) Pivmecillinam
2) Amoxicillin
3) Cefalexin
29
Typical duration of Abx in:
a) simple lower UTIs in women
b) immunosuppressed women, abnormal anatomy or impaired kidney function
c) men, pregnant women or catheter-related UTIs
a) 3 days
b) 5-10 days
c) 7 days
30
Management of lower UTIs in SYMPTOMATIC pregnant women?
1) send urine culture
2) treat with 7 day course of Abx (Abx depends on stage of pregnancy)
31
When should trimethoprim be avoided in pregnancy?
1st trimester --> teratogenic as is a folate antagonist.
It is not known to be harmful later in pregnancy but is generally avoided unless necessary.
32
When should nitrofurantoin be avoided in pregnancy?
3rd trimester (near term) --> risk of neonatal haemolysis
32
What can use of nitrofurantoin near end of pregnancy result in?
Neonatal haemolysis
33
What can use of trimethoprim in 1st trimester lead to?
congenital malformations, particularly neural tube defects (e.g., spina bifida).
34
Management of lower UTIs in ASYMPTOMATIC bacteriuria in pregnant women?
1) a urine culture should be performed routinely at the first antenatal visit
2) immediate 7 day Abx prescription (nitrofurantoin, amoxicillin cefalexin)
35
What are the 3 Abx typically used for UTIs in pregnancy?
1) Nitrofurantoin (avoided in the third trimester)
2) Amoxicillin (only after sensitivities are known)
3) Cefalexin (the typical choice)
36
What is the typical Abx used in pregnancy for UTIs?
Cefalexin
37
What is the rationale of treating asymptomatic bacteriuria in pregnant women?
Significant risk of progression to acute pyelonephritis
38
Management of UTIs in men?
1) Immediate Abx prescription for 7 days.
2) Urine culture: sent before antibiotics are started
39
1st line Abx for UTI in men?
As with non-pregnant women, trimethoprim or nitrofurantoin should be offered first-line
(unless prostatitis is suspected).
40
Management of UTIs in asymptomatic catheterised patients?
do not treat asymptomatic bacteria in catheterised patients
41
Management of UTIs in symptomatic catheterised patients?
1) Abx (7 day course)
2) consider removing or changing the catheter as soon as possible if it has been in place for longer than 7 days
42
How are lower UTIs in children handled differently to adults?
In contrast to adults, the development of a UTI in childhood should prompt an investigation for possible underlying causes and damage to the kidneys.
43
3 most common causative organisms of UTIs in children?
1) E. coli (80%)
2) Proteus
3) Pseudomonas
44
What are some predisposing factors for UTIs in children?
1) Incomplete bladder emptying:
- infrequent voiding
- hurried micturition
- obstruction by full rectum due to constipation
- neuropathic bladder
2) Vesicoureteric reflux
- a developmental anomaly found in around 35% of children who present with a UTI
3) Poor hygiene e.g. not wiping from front to back in girls
45
What is vesicoureteral reflux (VUR)?
When urine moves backward from the bladder to the kidneys.
Typically grow out of it.
46
Are UTIs in childhood more common in boys or girls?
Until 3 months of age --> more common in boys
After 3 months --> more common in girls
47
Presentation of UTIs in childhood?
Depends on age:
1) infants: poor feeding, vomiting, irritability
2) younger children: abdo pain, fever, dysuria
3) older children: dysuria, frequency, haematuria
Features that may suggest upper UTI: temperature > 38ºC, loin pain/tenderness
48
What are the indications for urine dipstick in children?
1) symptoms or signs suggestive of a UTI
2) unexplained fever of 38°C or higher (test urine after 24 hours at the latest)
3) an alternative site of infection but who remain unwell (consider urine test after 24 hours at the latest)
49
Is urine typically tested in children with suspected UTIs?
Yes
50
Management of UTIs in infants less than 3 months old?
Refer immediately to paediatrician
51
Management of lower UTIs in children >3 months?
Oral Abx for 3 days according to guiidelines (often trimethoprim, nitrofurantoin, cephalosporin or amoxicillin)
52
What is acute pyelonephritis?
Acute pyelonephritis is an infection of one or both of the kidneys.
53
Cause of pyelonephritis?
It occurs as a result of an ascending UTI which has spread from the bladder up towards the kidneys.
54
Clinical features of pyelonephritis?
Symptoms typically develop quickly; usually over a couple of days.
Similar presentation of lower UTIs plus additional triad:
1) fever
2) loin or back pain (unilateral or bilateral)
3) N&V
May also have:
- systemic illness
- loss of appetite
- haematuria
- renal angle tenderness on exam
- foul smelling urine
- confusion
55
What is urosepsis?
A life-threatening complication of pyelonephritis and can lead to septic shock
56
Signs of urosepsis?
- hypotension
- tachypnoea
- skin changes
- oliguria
57
How can pyelonephritis present in the elderly?
increased confusion or new incontinence.
58
How can pyelonephritis present in young children?
non-specific symptoms such as a fever, irritability and poor feeding
59
How is a diagnosis of pyelonephritis made?
history + exam (if a UTI is confirmed by culturing a urinary pathogen from the urine and other causes of loin pain and/or fever have been excluded)
60
What investigation is recommended in ALL patients with suspected pyelonephritis?
Mid-stream urine (MSU)/ catheter specimen urine (CSU)
These samples should be taken BEFORE starting empirical drug treatment.
61
Does a negative MSU exclude the diagnosis of pyelonephritis?
No
62
When is imaging recommended in pyelonephritis?
In recurrent pyelonephritis
63
What is imaging of choice in children with recurrent pyelonephritis?
US (quick and there is no risk of radiation)
64
Management of pyelonephritis?
1) Mainstay --> Abx 7-10 day course (empirical Abx should be started after urine cultures taken, can be tailored once the sensitivities are available)
2) Others:
- IV fluids
- Analgesia
- Antiemetics if required
65
Which patients with pyelonephritis should you consider hospital admission?
1) pregnant women
2) patients who are not improving in the community despite 48 hours of treatment
3) severe pain
4) signs of severe illness: tachycardia, hypotension, reduced urine output, tachypnoea, confusion etc
5) patients who are unable to tolerate oral fluids/medicines
6) patients at risk of developing complications:
- diabetes
- babies <3 months
- 65+ years
- known abnormalities of the of the genitourinary tract
66
What two things should you keep in mind with patients that have significant symptoms or do not respond well to treatment (pyelonephritis)?
1) renal abscess
2) kidney stones obstructing the ureter, causing pyelonephritis
67
Complications of pyelonephritis?
1) AKI
2) Urosepsis: if the bacteria enter the bloodstream, sepsis can occur
3) Perinephric/renal abscess
4) Premature labour in pregnancy
5) Chronic pyelonephritis
68
How can pyelonephritis affect pregnancy?
Premature labour in pregnancy
69
What is chronic pyelonephritis?
Characterised by scarring on the kidney which occurs after recurrent or persistent infections.
70
In men, what does acute urinary retention most commonly occur 2ary to?
BPH --> the enlarged prostate presses on the urethra which can make the bladder wall thicker and less able to empty.
71
What is obstructive uropathy?
A blockage preventing urine flow through the ureters, bladder and urethra.
72
What is swelling of the kidney known as?
Hydronephrosis
73
What is vesicoureteral reflux (VUR)?
Urine refluxing from the bladder back to the ureters.
74
What is a 'post-renal' AKI?
When obstructive uropathy leads to an acute reduction in kidney function.
75
What is 'pre-renal' AKI?
Caused by hypoperfusion of the kidneys (e.g., due to dehydration, sepsis or acute blood loss)
76
What is a 'renal' AKI?
Refers to damage within the kidney itself (e.g., due to glomerulonephritis or nephrotoxic medications).
77
What are the 3 broad categories of renal impairment?
1) Pre-renal
2) Renal
3) Post-renal
78
Presentation of an upper urinary tract obustruction (i.e. in the ureters)?
1) Loin to groin or flank pain on the affected side (due to stretching and irritation of ureter and kidney)
2) Reduced or no urine output
3) Non-specific symptoms e.g. vomiting
4) Impaired renal function on blood tests (i.e. raised creatinine)
79
Presentation of a lower urinary tract obstruction (i.e. in the bladder or urethra)?
1) Difficulty or inability to pass urine (e.g. poor flow, difficulty initiating urination, terminal dribbling)
2) Urinary retention, with an increasingly full bladder
3) Impaired renal function on blood tests (i.e. raised creatinine)
80
What imaing can be helpful in diagnosing obstructive uropathy?
US of the kidneys, ureters & bladder (KUB)
81
What does 'loin to groin' pain usually refer to?
"Loin to groin” pain usually refers to pain that circles from the kidney area at the back, round the sides and down into the groin.
82
What is the 'renal angle'?
The “renal angle”, also called the “costovertebral angle”, refers to the angle formed by the twelfth rib and vertebral column at the back.
The lower part of the kidneys are at the renal angle.
Tenderness in the renal angle suggests kidney pathology.
83
Common causes of upper urinary tract obstruction?
1) kidney stones
2) tumours pressing on ureters
3) ureter strictures (due to scar tissue narrowing the tube)
4) retroperitoneal fibrosis (development of scar tissue in the retroperitoneal space)
5) bladder cancer (blocking the ureteral openings to the bladder)
6) ureterocele (ballooning of the most distal portion of the ureter - usualy congenital)
84
Common causes of lower urinary tract obstruction?
1) BPH
2) prostate cancer
3) bladder cancer (blocking neck of bladder)
4) urethral strictures (due to scar tissue)
5) neurogenic bladder
6) constipation
85
What is a neurogenic bladder?
Refers to abnormal function of the nerves innervating the bladder and urethra.
This can result in overactivity or underactivity in the detrusor muscle of the bladder and the sphincter muscles of the urethra.
86
What are the key causes of a neurogenic bladder?
1) MS
2) diabetes
3) stroke
4) Parkinson's disease
5) brain or spinal cord injury
6) spina bifida
87
What problems can neurogenic bladder result in?
1) urge incontinence
2) increased bladder pressure
3) obstructive uropathy
88
Management of obstructive uropathy?
Removing or bypassing the obstruction:
1) Nephrostomy --> Involves surgically inserting a thin tube through the skin at the back, through the kidney and into the ureter. This tube allows urine to drain out of the body, into a bag.
2) Urethral catheter --> a tube, inserted through the urethra, into the bladder.
3) Suprapubic catheter --> a tube, inserted through the skin just above the pubic bone, directly into the bladder.
89
Is a nephrostomy used in an upper or lower urinary tract obstruction?
Upper
90
Is a urethral or suprapubic cathetic used in an upper or lower urinary tract obstruction?
Lower
91
Complications of obstructive uropathy?
- pain
- AKI (post-renal)
- CKD
- infection (from bacteria tracking up urinary tract into areas of stagnated urine)
- hydronephrosis (swelling of renal pelvis and calyces in the kidney)
- urinary retention and bladder distension
- overflow incontinence of urine
92
What is hydronephrosis? What is it caused by?
Hydronephrosis is swelling of the renal pelvis and calyces in the kidney.
This occurs due to obstruction of the urinary tract, leading to back-pressure into the kidneys.
93
What is idiopathic hydronephrosis a result of?
This is the result of a narrowing at the pelviureteric junction (PUJ): the site where the renal pelvic becomes the ureter.
This narrowing may be congenital or develop later.
94
Management of narrowing at the PUJ?
It can be treated with an operation to correct the narrowing and restructure the renal pelvis (pyeloplasty).
95
Typical presenting features of hydronephrosis?
- vague renal angle pain
- mass in kidney area
96
Treatment of hydronephrosis?
Treating underlying cause.
Pressure can be relived with:
a) percutaneous nephrotsomy: inserting a tube through the skin and kidney into the ureter, under radiological guidance
b antegrade ureteric stent: inserting a stent through the kidney into the ureter, under radiological guidance
97
What medications can cause urinary retention?
1) anticholinergics
2) TCAs
3) antihistamines
4) opioids
5) benzos
98
Clinical presention of acute urinary retention?
Subacute onset of:
1) inability to pass urine
2) lower abdo discomfort
3) considerable pain or distress
99
Pain in acute vs chronic urinary retention?
Acute - painful
Chronic - painless
100
In a patient with a background of chronic urinary retention, how may a patient with acute urinary retention present?
Overflow incontinence
101
Signs of acute urinary retention?
1) palpable distended bladder either on abdo or rectal exam
2) lower abdo tenderness
102
What examinations should all patients presenting with acute urinary retention have?
1) abdo
2) rectal
3) neuro
women --> pelvic
103
Investigations in acute urinary retention?
1) urinalysis & culture (might only be possible after urinary catheterisation)
2) U&Es and creatinine: assess for kidney injury
3) FBC and CRP: infection
104
Is PSA indicated in acute urinary retention?
No - typically elevated
105
What imaging is used to confirm the diagnosis of acute urinary retention?
Bladder US
106
Management of acute urinary retention?
Decompressing bladder via catheterisation
107
What bladder volume on US confirms diagnosis of acute urinary retention?
>300c
108
How is chronic urinary retention characterised?
Being painless and insidious
109
High pressure vs low pressure chronic urinary retention?
The terms “high” and “low” refer to the bladder pressure at the end of voiding.
High:
- abnormal renal function and/or bilateral hydronephrosis
Low:
- normal renal function
- normal kidneys (i.e. no hydronephrosis)
110
What is high pressure urinary retention typically due to?
Bladder outflow obstruction
111
What commonly occurs after catheterisation for chronic retention?
Decompression haematuria --> due to the rapid decrease in the pressure in the bladder.
112
Management of decompression haematuria following catheterisation for chronic retention?
It usually does not require further treatment.
113
