Urinary Tract Infection (UTI) Flashcards Preview

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Flashcards in Urinary Tract Infection (UTI) Deck (41)
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1
Q

What is dysuria?

A

Pain on micturition

2
Q

How does a UTI present?

A

Dysuria
Frequency
Smelly urine

Very young: unwell, failure to thrive

Very old: incontinence, off their feet

3
Q

Why do the ureters enter the bladder at an angle?

A

Enter bottom of bladder at angle so that increasing pressure from bladder as it fills -> closes off ureter and stops reflux of urine

4
Q

What are the bacteriostatic properties of the normal urinary tract?

A

Free flow of urine through normal anatomy- assumes drinking enough fluids

Low pH, high osmolarity, and high ammonia (NH3) content of normal urine

Prostatic secretions are bacteriostatic

Anti-bacterial antibodies

5
Q

How much of the urinary tract is normally sterile?

A

All urinary tract except for terminal urethra

6
Q

How can you bypass the terminal urethra to take a clean sample of urine?

A

Suprapubic aspirate of urine

-Needle straight into bladder

7
Q

Why do we take a midstream sample (or suprapubic aspirate) for urine MC&S?

A

Urinated sample will always be contaminated by terminal urethral flora

Initial void will wash terminal urethra -> sample taken after will be more sterile avoiding false positives

8
Q

Explain how you carry out a mid stream sample

A

Patient voids and stops mid-stream, discarding urine, then collects next volume of urine = MSSU (midstream specimen of urine

9
Q

Can you ever get rid of all terminal urethral flora by a MSSU?

A

No

Urethral flora will be diminished by always present

Will always grow in culture so never a negative result

10
Q

What does MSSU stand for?

A

Mid Stream Specimen Urine

11
Q

How do you tell contamination from real infection in MSSU?

A

Microbiology for culture under set conditions

Bacteria multiply in log phase growth

10^5 per ml

12
Q

A MSSU culture result of 10^3 would indicate what?

A

10^3 and 10^4 need to be interperated clinically:

  • If symptomatic probably infection
  • If asymptomatic 50% infection
13
Q

In which populations is an MSSU difficult to collect?

A

Young children and elderly

14
Q

What are the problems with interpretation of urine culture?

A

Some bacterial species are not normally present in terminal urethra/rectal flora and may be pathogenic at low colony numbers

15
Q

What micro-organisms cause UTI?

A

Bacteria mostly = gut flora, especially E. coli

Viral infection rare

16
Q

What is the route of infection in UTI?

A

Almost always ascending from terminal urethra

Infection in kidneys has usually spread up from bladder infection

17
Q

Which is more serious:

Upper UTI or Lower UTI?

A

Upper UTI more serious

18
Q

What is urethritis?

A

INFECTION of urethra

Usually itis = inflammation but here almost always infection

19
Q

What is cystitis?

A

Inflammation/infection of bladder

20
Q

What is ureteritis?

A

Infection of the ureter

21
Q

What is acute pyelonephritis?

A

Kidney infection/ inflammation

If recurrent/ prolongued infection -> chronic pyelonephritis

22
Q

What are the predisposing factors for a UTI?

A
  1. Stasis of urine
  2. Pushing bacteria up urethra from below
  3. generalised predisposition to infection
23
Q

How can stasis of urine come about?

A
  1. Obstruction, whether congenital (presents in childhood) or acquired (adults).
  2. Loss of “feeling” of full bladder - spinal cord/ brain injury
24
Q

How can pushing bacteria up urethra from below come about?

A

Sexual activity in females

Catheterisation (and other urological procedures)

25
Q

What may cause a generalised predisposition to infection?

A

e.g. Diabetes

26
Q

How does obstruction of the urethra effect the urinary tract?

A

Upper urethral and bladder dilatation

If this continues -> bilateral hydroureter -> bilateral hydronephrosis -> chronic renal failure

27
Q

What does unilateral hydroureter indicate as opposed to bilateral hydroureter?

A

Unilateral = obstruction above bladder

Bilateral = obstruction below bladder

28
Q

What are the consequences of obstruction?

A

Proximal dilatation

Slowed urine flow -> cannot flush out bacteria -> infection

Slowed urine flow -> sediments form -> calculous formation -> obstruction -> repeat cycle

29
Q

What is the obstruction triad?

A

Infection -> calculi -> obstruction -> infection etc

30
Q

What is obstruction in children usually caused by?

A

There are numerous renal tract abnormalities
-Usually one of these

Always investigate at first presentation and send to paediatric surgeons

31
Q

What is the most important renal tract abnormality for obstruction in children?

A

Vesicoureteric reflux

32
Q

What is vesicoureteric reflux?

A

Normally ureters insert into bladder at angle

Decreased angulation in vesicoureteric reflux -> ureter isnt closed off by increasing bladder pressure -> reflux -> hydroureter -> hydronephritis

33
Q

What are common causes of obstruction in adults?

A

Males - Benign Prostatic Hyperplasia (NOT a tumour) -> functional and anatomical obstruction

Females - Uterine prolapse

Both sexes - Tumours and calculi

34
Q

What is the residual bladder volume?

A

Volume of fluid left in bladder after urination

You want this to be as small as possible to prevent static urine

35
Q

How does spinal cord/ brain injury predispose to UTI?

A

Decreased sensation -> no sense of when to micturate and do not know how to empty bladder completely -> leave urine in bladder -> high residual volume -> stasis of urine

36
Q

How does female sexual activity tend to lead to UTI?

A

Move lower urethral flora up the tract (back wall of urethra is just in front of vagina)

37
Q

Why are females more predisposed to UTI?

A

Short urethra

Lack of prostatic bacteriostatic secretion

Closeness of urethral orifice to rectum

Sexual activity (helps if void after intercourse)

Pregnancy - pressure on ureters and bladder

38
Q

How does catheterisation predispose to UTI?

A

Any instrumentation of urinary tract tends to move lower urethral flora up the tract

39
Q

How does diabetes predispose to UTI?

A

Glucose in urine

Poor function of WBC

40
Q

What are the acute complications of UTI?

A

Severe sepsis and septic shock

41
Q

What are the chronic complications of UTI?

A

Chronic damage to kidneys if repeated infections (chronic pyelonephritis) -> hypertension, chronic renal failure

Calculi -> obstruction -> hydronephrosis -> hypertension, chronic renal failure