Urology: UTI & Urinary Retention Flashcards
Lower UTI vs pyelonephritis?
Lower UTI –> nfection in the bladder, causing cystitis (inflammation of the bladder).
Pyelonephritis –> Inflammation of the kidney resulting from bacterial infection.
What does the inflammation affect in pyelonephritis?
1) kidney tissue (parenchyma)
and
2) renal pelvis (where ureter joins kidney)
Why are UTIs more common in women?
Shorter urethra
What is the 1ary source of bacteria for UTIs?
Faeces: normal intestinal bacteria, such as E. coli, can easily journey to the urethral opening from the anus.
What is the typical way that intestinal bacteria is spread to urethra?
Sexual activity is a crucial method for spreading bacteria around the perineum
Risk factors for UTIs?
1) sexual activity
2) poor hygiene
3) incontinence
4) catheters
Presentation of a lower UTI?
- 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)
How can lower UTIs often present in older and frail patients?
Acute confusion is commonly the only symptom in older and frail patients
Urine dipstick vs urine culture?
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.
Investigations in lower UTI?
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.
Who should urine DIPSTICKS not be used in the diagnosis of a UTI in (as less reliable)?
1) women >65
2) men
3) catheterised patients
Who is an MSU important in lower UTI (9 circumstances)?
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.
At what age are urine dipsticks less reliable?
> 65
What defines a ‘recurrent’ UTI?
2 episodes in 6 months or 3 in 12 months
Management of a UTI in non-pregnant women?
1) nitrofurantoin or trimethoprim for 3 days
2) send a urine culture if:
- aged > 65 years
- visible or non-visible haematuria
What is the cause of nitrites in the urine in a UTI?
Gram-negative bacteria (e.g., E. coli) break down nitrates (a normal waste product in urine) into nitrites.
How are leukocytes tested for on a urine dipstick?
Leukocyte esterase (a product of leukocytes) is tested on a urine dipstick, indicating the number of leukocytes in the urine.
Cause of leukocytes in the urine?
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.
What do RBCs in the urine indicate?
Indicates bleeding and is a common sign of infection. Can also be present with other causes, such as bladder cancer or nephritis.
Microscopic vs macroscopic haematuria?
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.
Are nitrites or leukocytes in the urine a better indicatino of infection in a UTI?
Nitrites
What urine dipstick result indicates that a patient will LIKELY have a UTI?
Nitrites or leukocytes AND red blooc cells
How does the presence of nitrites or leukocytes guide management in UTIs?
Only nitrites –> worth treating as a UTI
Only leukocytes –> a sample should be sent to the lab for further testing.
What is the most common cause of UTIs?
Escherichia coli (gram-negative, anaerobic, rod-shaped bacteria)
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)
What are the 2 key Abx used in the management of UTIs?
1) nitrofurantoin
2) trimethoprim (often associated with high rates of bacterial resistance)
Who is nitrofurantoin avoided in (in non-pregnant women)?
Avoided in patients with an eGFR <45
What are 3 alternatives to nitrofurantoin & trimethoprim in UTIs?
1) Pivmecillinam
2) Amoxicillin
3) Cefalexin
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
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)
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.
When should nitrofurantoin be avoided in pregnancy?
3rd trimester (near term) –> risk of neonatal haemolysis
What can use of nitrofurantoin near end of pregnancy result in?
Neonatal haemolysis
What can use of trimethoprim in 1st trimester lead to?
congenital malformations, particularly neural tube defects (e.g., spina bifida).
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)
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)
What is the typical Abx used in pregnancy for UTIs?
Cefalexin
What is the rationale of treating asymptomatic bacteriuria in pregnant women?
Significant risk of progression to acute pyelonephritis
Management of UTIs in men?
1) Immediate Abx prescription for 7 days.
2) Urine culture: sent before antibiotics are started
1st line Abx for UTI in men?
As with non-pregnant women, trimethoprim or nitrofurantoin should be offered first-line
(unless prostatitis is suspected).
Management of UTIs in asymptomatic catheterised patients?
do not treat asymptomatic bacteria in catheterised patients
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
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.
3 most common causative organisms of UTIs in children?
1) E. coli (80%)
2) Proteus
3) Pseudomonas
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