UTI

Question 1

what is the presentation of UTI?

Answer 1

• dysuria
  
  • pain, stinging or burning when passing urine
• frequency
• urgency
• cloudy, smelly urine
• incontinence
• suprapubic pain or discomfort
• confusion in elderly

Question 2

how does UTI present in very young?

Answer 2

unwell & failure to thrive

Question 3

how does UTI present in elderly?

Answer 3

incontinence and off their feet

Question 4

what are some normal bacteriostatic properties of the renal tract?

Answer 4

• free flow of urine
• low pH, high osmolality and high ammonia content of normal urine (low pH kills bacteria)
• prostatic secretions are bacteriostatic
• anti-bacterial antibodies

Question 5

what part of the renal tract is sterile?

Answer 5

All of it apart from the terminal urethra

Question 6

why is an MSSU done in order to reduce level of contamination?

Answer 6

initial urine is heavily contaminated, so it is voided and then stopped mid-stream. The next volume of urine is collected in the tube and will be less contaminated than the initial volume.

• urethral flora diminished but always present

Question 7

what number of CFU indicates infection from an MSSU culture usually?

Answer 7

10⁵

Question 8

what does it mean if a person has 10^3-4 CFU on microscopy?

Answer 8

infection sometimes

-if symptoms, treat

Question 9

what may be a problem of interpretation of MSSU culture?

Answer 9

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

Question 10

what are the main organisms that cause UTI?

Answer 10

• E.Coli
• klebsiella
• enterococcus
• pseudomonas
• staphylococcus saprophyticus
• candida albicans (fungal)

Question 11

what is the main route of infection?

Answer 11

almost always ascending

Question 12

what are the 3 main predisposing factors for UTI (aetiology)

Answer 12

• stasis of urine
• pushing bacteria up urethra from below
• generalised predisposition to infection

Question 13

what are the main reasons for stasis of urine and what are they due to?

Answer 13

1. obstruction

• congenital
• acquired

2. loss of ‘feeling’ of full bladder
   * spinal cord/brain injury

Question 14

what happens to bacteria that make their way up to the bladder?

Answer 14

their flagella cause them to stick to the epithelium and stay there & colonise- do not get flushed out

Question 15

what does obstruction at level of urethra cause?

Answer 15

bilateral hydroureter –> bilateral hydronephrosis –> chronic renal failure

Question 16

what does obstruction just below level of renal pelvis on 1 side cause?

Answer 16

unilateral hydroureter & hydronephrosis

Question 17

what are the main consequences of obstruction? (3)

Answer 17

• proximal dilatation
• slowed urine flow–> cannot flush out bacteria –> infection
• slowed urine flow–> sediments form–> stone formation –> further obstruction

Question 18

what are the most common causes of obstruction in adults?

Answer 18

men- BPH

women - uterine prolapse

Question 19

what are the main causes of pushing bacteria up urethra from below?

Answer 19

• sexual intercourse
• catheterisation

Question 20

what are some factors that lead to predisposition of the female sex to UTI?

Answer 20

• short urethra
• lack of prostatic bacteriostatic secretion
• closeness of urethral orifice to rectum
• sexual activity
• pregancy (puts pressure on ureters and bladder)

Question 21

what are some other factors which may predispose to UTI?

Answer 21

• congenital abnormalities ie duplex kidney
• oestrogen deficiency in post-menopausal women
• fistula between bladder & bowel
• spermicide coated condoms

Question 22

what may cause generalised predisposition to infection? (4)

Answer 22

• diabetes
• immunosuppression
• steroids
• malnutrition

Question 23

what are acute and chronic complications of UTI?

Answer 23

• acute - acute pyelonephritis, sepsis, septic shock
• chronic
• chronic pyelonephritis–> HT –> renal failure
• calculi –> obstruction –> hydronephrosis –> HT, chronic renal failure

Question 24

what is the difference between complicated and uncomplicated UTI?

Answer 24

• uncomplicated - healthy, sexually active young women, in which there is a clear correlation between episodes of UTI with having sexual intercourse
• complicated- those which occur in all other situations ie children, men, patients with abnormal renal tract etc. Require investigation

Question 25

how do you investigate UTI?

Answer 25

MSSU

• Urine dipstick
• blood
• protein
• leucocytes
• nitrites: better indication of infection than leucocytes
• send for MC&S if either nitrites / leucocytes

Question 26

what are leucocytes?

Answer 26

marker of inflammatory response

• leucocyte esterase tested for which is a breakdown product of leukocytes tht gives indication of no of leukocytes in urine

Question 27

how do you treat uncomplicated UTI?

Answer 27

Trimpethoprim or Nitrofurantoin for

• 3 days for simple lower UTI
• 5-10days if immunosuppressed, abnormal anatomy or impaired kidney function
• 7 days for men, pregnant women or catheter related UTIs

Question 28

if both trimethoprim/nitrofurantoin are contraindicated, what is given in its place?

Answer 28

Amoxicillin or Cefalexin

Question 29

how do you treat complicated UTI?

Answer 29

ciprofloxacin or co-trimoxazole

Question 30

what do UTIs in pregnancy increase risk of?

Answer 30

• pyelonephritis
• premature rupture of membranes
• pre-term labour

Question 31

Mx in pregnancy?

Answer 31

1st line: Nitrofurantoin

2nd line: cefalexin or amoxicillin

for 7 days (even with asymptomatic bacteruria)

Question 32

when is Nitro avoided in pregnancy?

Answer 32

3rd trimester as it is linked with haemolytic anaemia of newborn

Question 33

when is Trimethoprim avoided in pregnancy?

Answer 33

in 1st trimester or if on any other medication that affects folic acid