UTI Flashcards
What is a UTI
(1. ) Urinary tract infection is defined as bacteria in the urine COMBINED with clinical features.
(2. ) Bacteria in the urine alone is asymptomatic bacteriuria*
(3. ) Lower UTI = bladder (cystitis), prostate (prostatitis)
(4. ) Upper UTI = Pyelpnephritis
What is complicated and uncomplicated UTI
- Uncomplicated = Non-pregnant women
- Complicated = Pregnant, Men, Catherization, Children, recurrent UTI, immunocompromised etc
RF for UTI (11).
- Age
- Gender
- Abnormality of the renal tract
- Incomplete bladder emptying (e.g. prostatic obstruction).
- Abx use changes vaginal flora and promotes colonisation of E. coli
- Sexual activity.
- New sexual partner.
- Diabetes.
- Presence of catheter
- Pregnancy
- Immunocompromised
Aetiology of UTI
(1.) Majority caused by E.coli.
(2. ) Other common ones and what they’re associated with:
- proteus = renal stones
- klebsiella = catheter
- staphylococcus
- pseudomonas = recurrent UTI
Pathogenesis of UTI
Urine is usually sterile and resistant to colonisation. Ways bacteria can get in:
(1. ) Waste products unable to pass due to blockage (stones, BPE etc) may cause a build-up of bacteria
(2. ) Low urinary volume
(3. ) Stasis during pregnancy
(4. ) Catherization allowing colonisation
* NOTE* there is more ways of entry
Clinical features of UTI
Differentiate between lower and upper UTI.
(1.) Sx of Cystitis: frequency, urgency, dysuria, suprapubic pain, polyuria, haematuria
(2. ) Sx of prostatitis
- Perineal or suprapubic pain
- Pain on ejaculation
- Prostatic tenderness on DRE
(3. ) Sx of acute pyelonephritis
- Systemic Sx: fever, rigors, vomiting
- Hypotension
- Loin to groin pain
- Guarding or tenderness
Ix of UTI (6).
(1. ) Urine dipstick
- nitrite, leukocytes = tx as bacterial UTI
- DO NOT use to for catheter UTIs
(2. ) Urine microscopy
- WBC, RBC, Casts, bacteria
- if epithelial cells present this should be disregarded
(3. ) Urine culture indicated in complicated
- Bacteria = E.Coli, klebsiella, proteus, enterococcus, staphy
- NOT picked up in culture = TB, Mycoplasma, Schimisatsosis, Candidia
- Indicated: pregnancy, recurrent infections, IMC, tx failure, diabetics, catheter, older age
- NOT required for symptomatic lower UTI in non-pregnant women.
(4. ) MSU Urine collection
(5. ) Abx sensitivities
(6. ) Renal tract US/CT: Pyelonephritis, men, children, recurrent infections
Mx of UTI (5.)
(1. ) Education + awareness
- Inc risk = frequent sexual intercourse, new sexual partner
- Advice: Inc fluid intake, Void pre and post intercourse, Hygiene
(2.) No Tx for: asymptomatic bacteriuria in adults with catheter & non-pregnant women
(3. ) Uncomplicated:
- Not necessary to send MSU
- Abx for 3 days
(4. ) Complicated:
- Always send sample for culture
- Abx for 7 days
(5. ) Abx treatment: Nitrofurantoin or trimethoprim
- AVOID broad spectrum abx
- CI = 3rd trimester, reduced renal function
Pathogenesis of Catheter-associated UTI
- One of the most common healthcare acquired infections
- Insertion may carry organisms into the bladder
- Formation of biofilms, protected from flow of urine, host defences, abx
- Incomplete voiding
Ix of Catheter-associated UTI
- Do not dipstick (No diagnostic value)
- Send MSU only if symptomatic
- Cultures should always be sent and interpreted with caution
- Change or remove catheter before starting Abx
Complications of long-term catheters
- UTI/Pyelonephritis
- Stones
- Obstructions
- Chronic inflammation
Should asymptomatic bacteriuria in pregnancy be treated?
Yes it should still be treated as some can go on to develop acute symptomatic pyelonephritis
Ix of UTI in pregnancy
- Culture rather than dipstick
- Positive culture should be confirmed with a second sample
- Culture after 1w of tx to confirm eradication
Mx of UTI in pregnancy
- Penicillin and cephalosporins are safe to use in pregnancy
- Avoid:
- Ciprofloxacin, trimethoprim in 1st trimester
- Nitrofurantoin in 3rd trimester
Pathophysiology of Pyelonephritis
- Infection of parenchyma and soft tissues of renal pelvis/upper ureter
- Predominantly affects women <35y
- Routes of infection
- Ascending = urethra colonised with bacteria. This can happen during intercourse.
- Haematogenous = S.aureus, Candida
- Lymphatic Spread (rare)
