Session 7 - UTI Flashcards Preview

Semester 3 - Urinary > Session 7 - UTI > Flashcards

Flashcards in Session 7 - UTI Deck (59):
1

Outline the three main defences against UTI

• Regular flushing during voiding
• Length of urethra
• Antibacterial secretions into urine

2

What does regular flushing during voiding do to help avoid UTIs?

• Removes organisms in distal urethra

3

Outline four host factors which predispose to UTI

• Short urethra - More infections in female
• Obstruction
• Neurological - Incomplete emptying, residual urine
• Ureteric reflex - Ascending infection from bladder, especially in children

4

Give four ways obstructions occur in the urethra

• Enlarged prostate
• Pregnancy
• Stones
• Tumours

5

Outline five bacterial factors which predispose micro-organisms to urinary tract infection

• Fimbriae allow attachment to host epithelium
• Faecal flora migrate across periurtheral area
• K antigen permits production of polysaccharide capsule
• Haemolysins damage host membranes and cause renal damage

Urease breaks down urea creating a favourable environment for bacterial growth

6

What bacteria types commonly cause UTI's?

• Gram -'ve bacteria

7

What is the commonest type of UTI?

• An infection of the lower tract - Cystitis

8

What is the most common cause of UTIs?

• Migration of e.coli from faecal flora across peri-urethral area

9

What can cause upper UTI's?

• Haematogeneous (blood borne) or ascending routes of infection
• Upper UTI (pyelonephritis)

10

Give three types of lower UTI

• Bacterial cystitis
• Abacterial cystitis
• Prostatitis

11

Give main symptoms of bacterial cystitis

• Frequency and dysuria, often with pyuria and haematuria

12

Give main symptoms of abacterial cystitis

• Frequency and dysuria, often with pyuria and haematuria

13

How could you tell the difference between bacterial and abacterial cystitis?

• Bacterial cystitis will be coupled with a bacteraemia

14

Give main symptoms of prostatitis

Fever, dysuria, frequency with perineal and lower back pain

15

Give two types of upper UTI's

Acute pyelonephritis
Chronic interstitial nephritis

16

What are symptoms of acute pyelonephritis

• Symptoms of cystitis
• Fever and loin pain

17

What are symptoms of chronic interstitial nephritis

Renal impairment following chronic inflammation - infection one of many causes

18

What is an asymptomatic UTI?

• Covert Bacteriuria
• Detected only by culture

19

Give two examples of when an asymtpomatic UTI would be important?

Pregnancy
Childhood

20

What is the main organism responsible for UTI's?

• Coliforms - e.coli - GRAM NEGATIVE SO STAINS PINK

21


What bacteria cause young women and hospitalised patients to develop UTI's?

Staph Saprophyticus

22

Why is there a difference between the bacteria types which cause UTI in hospital and the community?

• Hospital provides extra risk factors, such as catherterisation which can provide a biofilm surface

23

What are two types of UTI?

• Complicated
• Uncomplicated

24

What is an uncomplicated UTI?

• Vast majority of UTI's

Found in healthy women

25

What is a complicated UTI?

• Anything which isn't in a healthy woman (Pregnancy, treatment failure, suspected pyelonephritis, males, pediatric)

26

How is an uncomplicated UTI investigated?

• No need for urine culture

Infection indicated by Nitirite/Leukocyte esterase dipstick testing

27

What is leukocyte esterase?

• An enzyme produced by WBCs which can be detected in the urine in the event of infection

28

What does a positive nitrite test usually indicate?

• That the cause of the UTI is a gram negative organism (usually e.coli)

Gram -'ves

29

What investigations need to occur in a complicated UTI?

• A urine sample must be take, from which a culture will be drawn so bacteria can be identified

30

Give four methods of collecting a urine sample

• Mid stream specimen
• Adhesive bag over genitalia
• Catheter sample from special tube in catheter
• Suprapubic aspiration

31

How are urine samples collected?

• Mid stream, as urethera's normal flora should not be collected

32

How can samples be collected from small children?

• Adhesive bag places over genitals

33

What is the issue with using an adhesive bag to collect urine from children?

• False positive rate of 20%

34

Where are catheter samples collected from?

• Needle placed up catheter tube
• Not from the bag

35

What is suprapubic aspiration of urine?

• Needle placed through suprapubic region of pelvis into bladder and urine aspirated up

36

How are collected samples stored between collection and culture?

• Transported at 4*C with a small amount of boric acid in collection tube
• Prevents bacterial division

37

• Prevents bacterial division
What investigations can be performed on cloudy urine?

• Turbidity test
• Dipstick testing

38

What is turbidity?

• Whether the urine looks cloudy - If so, indicative of UTI

39

What are four dipstick tests which can be performed on urine?

• Leukocyte esterase - Indicates presence of WBCs
• Nitrite - Indicates presence of nitrate reducing bacteria
• Haematuria - Present in UTI and many other conditions
• Proteinuria - Present in UTI and many other conditions

40

In what 6 situations is microscopy used on urine culture?

• Kidney disease
• Suspected endocarditis
• Children under 6
• Schistosomiasis
• Suprapubic aspirate
• When requested

41

What is urine culture and what needs to occur before infection can be confirmed?

• A number of colony forming units must occur - >100,00 per ml (10^5 cfu/ml) distinguished bacteriuria/contamination

42

What are the five main advantages of urine culture?

• To investigate complicated UTIs
• Gives epidemiology of isolates
• Sensitivity testing
• Specificity testing
• Control of specimen quality
○ Can differentiate between properly collected and contaminated samples (poorly collected samples may contain epithelial cells)

43

What 5 details are needed to correctly interpret a urine culture?

• Clinical details
○ Symptoms
○ Previous antibiotics
• Quality of specimen
• Delays in culture
• Microscopy
• Organsims location

44

What is sterile pyuria?

Pus in urine

45

What does sterile pyuria indicate?

• A UTI is present but unable to be cultured

46

Give three situations where sterile pyuria would be present?

• Patient already treated with antibiotics
• OR infected with bacteria that are difficult isolate or culture

OR can be due to tuberculosis or appendicitis (appendix stuck on bladder

47

What are three other causes of UTI symptoms

• Vaginal infection/inflammation
• Sexually transmitted pathogens
• Mechanical/physical/chemical causes

48

What are general treatments for UTI?

• Increase fluid intake
• Address underlying disorders

49

How is an uncomplicated UTI treated?

• 3 day course of antibiotics
• 3 day course reduces the selection pressure for resistance

50

What is given for complicated UTI treatment?

5 day course antibiotics

51

Should amoxicillin be used to treat complicated UTI's?

• No

50% of isolates (bacteria) resistance

52

How should pyelonephritis/septicaemia be treated?

• 14 day course of antibiotics
• Use more potent agent with systemic activity

53

When is antibiotic prophylaxis indicated?

• Three or more episodes of UTI in one year

No treatable underlying condition

54

What is antibiotic prophylaxis

• Single, low, nightly dose of antibiotics to prevent bacteria build up in static urine
• All breakthrough infections documented

55

What is pyelonephritis?

• Infection in kidney

56

What is the worst case scenario in a UTI?

• Bacteria manage to invade blood stream from urinary tract
• Gram negative septicaemia will occur

57

What are you likely to see in a culture of contaminated urine?

• Simple Squamous Epithelial cells

58

What is sensitivity of a test?

The rate of true positives

59

What is specificity of a test?

Rate of true negatives