Brainscape's Knowledge GenomeTM

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


See full index

104 Theme 3 - Kidneys and Urinary Tract > Urinary tract infections > Flashcards

Urinary tract infections Flashcards

1
Q

How common are UTIs?

A

2nd only to resp infections; 1-3% of all GP consultations.

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

Which groups are at risk of morbidity?

A

Significant cause of morbidity in females of all ages, infant boys and older men.

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

Who is most likely to get a UTI?

A

Up to 50% of women in lifetime, many recurrent (20% within 6 months), most not severe

1 to 2% of infants (boys < 3 months old 3x> girls)

Men rare until old age (prostatic enlargement)

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

____% elderly have asymptomatic bacteriuria

_____% of all nosocomial infections in men and women are UTIs; _______% of these develop secondary to indwelling catheters.

A

20% elderly have asymptomatic bacteriuria.

Forty percent of all nosocomial infections in men and women are UTIs; 80% of these develop secondary to indwelling catheters.

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

What are the consequences of UTI?

A

Societal and individual costs – health care costs (GP, ED and hospital), time missed from work

Frequent recurrences

Uncontrolled infection / sepsis

Renal damage in young children

Preterm birth

Recurrent courses of AB contribute to antimicrobial resistance and risk of CDI (C. difficile infection)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the types of uncomplicated UTIs?

A

Uncomplicated “Lower” UTI

  • Cystitis
  • Urethritis, prostatitis, epididymo-orchitis

Uncomplicated “Upper” UTI

•Acute pyelonephritis

Uncomplicated = no anatomical or neurological abnormalities of the urinary tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the risk factors for an uncomplicated UTI compared to a complicated UTI?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is pathogenesis?

A

Balance between host defences and organism virulence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the host factors for a lower UTI?

A
  • Obstruction (prostatic hypertrophy, urethral valves or stricture)
  • Poor bladder emptying (neuropathic (MS, spinal cord injury), bladder diverticula, pelvic floor disorders)
  • Catheterisation/instrumentation
  • Vesico-enteric fistula
  • Sex (female – vaginal or anal; male – insertive anal)
  • Diabetes
  • Genetics: non-secretors of ABH blood group antigens, esp in premenopausal women; and variable expression of the CXCR1 receptor, involved in neutrophil activation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the host factors for an upper UTI?

A

May follow on from lower UTI

Vesico-ureteric reflux

Obstruction (eg calculus, stricture)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the pathogenesis of a UTI?

A
  1. Contamination of the periurethral area with a uropathogen from the gut
  2. Colonisation of the urethra and migration to the bladder
  3. Colonisation and invasion of the bladder, mediated by pili and adhesins
  4. Neutrophil infiltration
  5. Bacterial multiplication and immune system subversion
  6. Biofilm formation
  7. Epithelial damage by bacterial toxins and proteases
  8. Colonisation of the kidneys
  9. Host tissue damage by bacterial toxins
  10. Bacteremia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What 3 factors does bacterial virulence depend on?

A
  1. Adherence
  2. Invasion
  3. Evasion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How does UPEC acheive adherence?

A

In the bladder, uropathogenic Escherichia coli (UPEC) expression of type 1 pili is essential for colonization, invasion and persistence.

P-pili confer tropism to the kidney

UPEC are highly adhesive so are proficient in retrograde ureteral ascent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How is a diagnosis of a UTI made?

A

Clinical symptoms

Urine dipstick testing

Urine culture

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

What are the symptoms of cystitis?

A

bladder and urethral symptoms

overlap with urethritis

dysuria, frequency, urgency, suprapubic pain, nocturia

cloudy urine/visible blood

Children, elderly and catheterised can be non-specific, such as delirium, lethargy so consider the diagnosis among other causes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the symptoms of pyelonephritis?

A

fever, rigors, loin pain

renal angle tenderness

often lower UTI symptoms in addition

if pain radiation to groin - stone?

risk of bacteraemia

17
Q

How is a clinical diagnosis of a UTI made?

A

Dipstick test at point of care. Main use to determine treatment if symptoms vague:

  • Not diagnostic on their own
  • Not useful if >65y or if catheterised
  • Look for nitrites, leucocytes and red blood cells (RBC)

Don’t need to send urine for culture in simple 1st episode cystitis in a non-pregnant adult female

18
Q

What are the NICE guidelines on diagnosing UTIs in females under 65?

A
19
Q

How is a laboratory diagnosis of a UTI made?

A

Send to lab for culture

  • pregnant, children, men, elderly, pyelonephritis, recurrence, failed treatment, abnormal urinary tract, renal impairment

Principles of a urine culture:

Urine in the bladder should be sterile in the absence of a UTI

However, it can be contaminated by bacteria colonising the distal urethra, or hands/genital contamination.

A mid-stream urine (MSU) reduces the effects of urethral contamination by avoiding the initial and end stages of micturition. The initial urine flow washes away urethral colonisers.

Also minimise the growth of any contaminants by rapid transport to lab (<4h), and/or boric acid preservative and/or refrigerate

20
Q

What types of urine specimens are there?

A

Midstream urine

Suprapubic aspirate

Catheter urine

acute

intermittent self catheterisation

indwelling

Not recommended: clean catch urine; bag urine; pad urine.

21
Q

How does a patient collect a mid stream urine sample?

A
22
Q

What is the use of boric acid in midstream urine samples?

A

The presence of boric acid helps to maintain the microbiological quality of the specimen, it prevents cell degradation and overgrowth of organisms that can occur if the sample is not analysed within 4 hours of collection.

However, boric acid can cause false

negative culture if urine not filled to correct mark on specimen bottle and can affect urine dipstick tests

23
Q

How is a laboratory diagnosis made using microscopy?

A

White cells represent inflammation in the urinary tract

Automated urine analysers in lab scan for red cells, white cells and organisms

Discard without culturing if scan negative (unless immunosuppressed or neonate)

24
Q

How is a laboratory diagnosis made using culture and antibiotic sensitivity?

A

quantitative

>105 organisms per ml is “significant bacteriuria” (in MSU only)

ie, probably not contaminants (90% specific)

UTI can be < 105 cfu/mL

Mixed growth may represent contamination >> true mixed infection

25
Q

How is antibiotic treatment used for UTI?

A

Empiric treatment so need to consider:

  • target organisms
  • route of administration
  • target site
  • side effects
  • resistance (known or likely)
26
Q

What does this show?

A

Antibiotic sensitivity testing

27
Q

The main risk factor for resistant E coli in the community is what?

A

The main risk factor for resistant E coli in the community is previous antibiotic treatment

28
Q

How does antibiotic resistance vary?

A

Changes over time

Varies geographically

29
Q

How do we know about antimicrobial resistance (AMR) rates?

A

Approximately 98% of hospital microbiology laboratories in England voluntarily report routine antimicrobial susceptibility testing (AST) results, with patient demographic information, to the PHE national laboratory surveillance system.

This is then used to inform antibiotic prescribing guidance

However this may be biased in that it is only based on isolates sent for diagnostic testing – ie not all UTIs

So a key recommendation of the English Surveillance Programme for Antimicrobial Utilisation and Resistance (ESPAUR) is sentinel surveillance, which base resistance estimates on AST data from specimens collected from a wider range of patients.

30
Q

How are UTIs prevented?

A

Correct any underlying host causes (uncontrolled DM)

Antibiotic prophylaxis (temporary, between 6m and 2y; not evidence based)

Behavioural changes eg high fluid intake (cranberry juice not recommended any more), void after sex, double void.

31
Q

How do catheter associated UTIs develop?

A

Bacteria colonise the catheter and bladder at a rate of 3-5% people / catheter day

Removal of catheter will clear bacteria in most cases

Usually asymptomatic, but some will develop UTI, and bacteremia, sepsis and death may result.

21% of patients with an E coli bloodstream infection had UC inserted/ removed/ manipulated in prior 7days

32
Q

It is estimated that _____% of CAUTI events are avoidable

A

It is estimated that 69% of CAUTI events are avoidable

33
Q

How are CAUTIs prevented?

A

Use only for a good reason:

  • Measurement of urine output in acutely unwell
  • Mx of acute retention or obstruction
  • Selected surgical procedures

Aseptic insertion

Closed drainage system

Daily review of need: remove

promptly when no longer indicated

Consider alternatives

34
Q

How is a CAUTI diagnosed?

A
35
Q

What is asymptomatic bacteriuria?

A

Best left untreated unless pregnant

Extremely common in elderly patients; organisms often lack virulence factors

Treatment is not benign – adverse effects, financial cost, development of resistant strains and risk of C. difficile infection

36
Q

What is the difference between a relapse and recurrence?

A

Relapse = the same uropathogen causes UTI symptoms within 2 weeks of completing appropriate AB treatment

Recurrence = at least 2 culture-proven episodes in 6 months, or at least 3 in 1 year

  • beyond the initial 2 weeks
  • or a different uropathogn

104 Theme 3 - Kidneys and Urinary Tract (13 decks)

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