UTI Flashcards
1
Q
What is the definition of a UTI?
A
The presence of a pure growth of >105 organisms per mL of fresh MSU.
2
Q
What is the difference between an upper UTI and a lower UTI?
A
- Lower UTI: urethra (urethritis), bladder (cystitis), prostate (prostatitis).
- Upper UTI: renal pelvis (pyelonephritis).
3
Q
What is urethral syndrome or abacterial cystitis?
A
- Up to a third of women with symptoms have negative MSU (= abacterial cystitis or the urethral syndrome).
4
Q
How are UTIs classified?
A
- UTIs may be uncomplicated (normal renal tract + function) or complicated (abnormal renal/GU tract, voiding diffi culty/obstruction, decreased renal function, impaired host defences, virulent organism, eg Staph. aureus).
- Uncomplicated = women
- Complicated = men and pregnant women
5
Q
What are the risk factors of UTIs?
A
- Increased bacterial inoculation:
- Sexual intercourse
- Urinary incontinence
- Faecel incontinence
- Constipation
- Increased binding of uropathogenic bacteria
- Exposure to spermicide in women (by diaphragm or condoms)
- Menopause
- Decreased oestrogen
- Decreased urine flow
- Dehydration
- Obstructed urinary tract
- Increased bacterial growth
- Pregnancy
- NB: in preg nancy, UTI is common and often asymptomatic, until serious pyelonephritis or premature delivery (± fetal death) supervenes, so do routine dipstick in pregnancy.
- Decreased host defence (immunosuppression)
- DM)
- Urinary tract obstruction
- Stones
- Catheter
- Urine in catheterized bladders is almost always infected—CSUS and treatment are pointless unless the patient is ill.
- Malformation
- Pregnancy
6
Q
What are the causative organisms that cause UTIs?
A
- Mainly gram negative bacteria and anaerobes from the bowels and vaginal flora
- E. coli is the main organism (75–95% in the community but >41% in hospital).
-
Staphylococcus saprophyticus
- Honeymoon cystitis
- Occasionally other enterobacteriaceae such as Proteus mirabilis and Klebsiella pneumonia, and other bacteria such as
7
Q
What is sterile pyuria?
A
When the white cell count is high but there the urine is sterile on culture
8
Q
What are the causes of sterile pyuria?
A
Infection related:
- TB
- Recently treated UTI
- Inadequately treated UTI
- Appendicitis
- Prostatitis
- Chlamydia
Non-infection related:
- Calculi
- Polycystic kidney
- Recent catheter
- Pregnancy
- SLE
- Drugs (steroids)
- Chemical cystitis
9
Q
What are the symptoms of cystitis?
A
- Frequency
- Dysuria
- Urgency
- Haematuria
- Supra pubic pain
- Polyuria
10
Q
What are the symptoms of prostatitis?
A
- Flu-like symptoms
- Fever
- Malaise
- Nausea
- Urinary symptoms
- Pain
- Perineum
- Rectum
- Scrotum
- Penis
- Bladder
- Lower back
- Swollen or tender prostate on PR
11
Q
What are the symptoms of acute pyelonephritis?
A
- High fever
- Rigors
- Vomiting
- Loin pain and tenderness
- Costovertebral pain
- Associated cystitis symptoms
- Oliguria (if acute kidney injury)
- Septic shock
12
Q
What are the signs of UTI?
A
- Fever
- Abdominal or loin tenderness
- Foul-smelling urine
- Occasionally distended bladder
- Enlarged prostate.
- If there is vaginal discharge consider PID
13
Q
What are the tests that are carried out to investigate UTI?
A
- If symptoms are present, dipstick the urine
- Treat empirically if nitrites or leucocytes are +ve while awaiting sensitivities on an MSU.
- If dipstick is –ve but patient symptomatic, send an MSU for lab MC&S to confirm this.
- Send a lab MSU anyway if male, a child (OHCS p174; do ultrasound), pregnant, immunosuppressed or ill.
- A pure growth of >105 organisms/mL is diagnostic. If 20 WBCS/mm3 ), this may still be significant; treat if symptomatic. Cultured organisms are tested for sensitivity to a range of antibiotics; check local sensitivity patterns
- Blood tests
- FBC
- U&Es
- CRP
- Blood cultures
- Consider fasting glucose
- PSA
- Imaging
- USS and referral to urology for assessment
- (CTKUB, cystoscopy, urodynamics) for UTI in children; men; if failure to respond to treatment; recurrent UTI (>2/year); pyelonephritis; unusual organism; persistent haematuria.
14
Q
How can patients prevent UTIs?
A
- Drink more water
- Antibiotic prophylaxis, continuously or postcoital, decreases UTI rates in females with many UTIS.
- Self-treatment with a single antibiotic dose as symptoms start is an option.
- Drinking 200–750mL of cranberry or lingo berry juice a day, or taking cranberry concentrate tablets, decreases risk of symptomatic recurrent infection in women by 10–20% 5 (may inhibit adherence of bacteria to bladder uroepithelial cells; avoid if taking warfarin).
- There is no evidence that post-coital voiding, or pre-voiding, or advice on wiping patterns in females is of benefit
15
Q
How are UTIs managed in non-pregnant women?
A
- Drink plenty of fluids; urinate often (don’t ‘hold on’).
- Consider empirical treatment for presumed E. coli in otherwise healthy women who present with lower UTI: local sensitivities vary but consider trimethoprim 200mg/12h PO or nitrofurantoin, eg 50mg/6h PO for 3–6d (if normal renal function), amoxicillin 500mg/8h PO. Alternative: cefalexin 1g/12h (if eGFR >40).
- 2nd line: co-amoxiclav PO (7d course).
- The latter 2 may cause problems with C. difficile.
- If there is no response, do a urine culture. • In case of vaginal itch or discharge consider vaginal examination and swabs for other diagnoses, eg thrush, chlamydia, other STIS. • In non-pregnant women with upper UTI, take a urine culture and treat with, eg co-amoxiclav 1.2g/8h IV,then oral when afebrile, complete 7d course. Avoid nitrofurantroin as it does not achieve eff ective concentrations in urine. Resistance to trimethoprim is common. Non-pregnant women with asymptomatic bacteriuria do not need antibiotics so screening is not recommended.
