UTI Flashcards
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What is bacteriuria?
Bacteria in urine, may be asymptomatic or symptomatic (not a disease)
What is a UTI?
Urinary tract infection; diagnosis based on symptoms and signs; tests which prove bacteria in urine may provide additional info (no ‘gold standard’ bacterial count)
Where is a lower UTI?
Bladder (cystitis)
Where is an upper UTI?
Pyelonephritis (infection of kidney/renal pelvis)
What is abacterial cystitis/urethral syndrome?
Diagnosis of exclusion in pts with dysuria and frequency, without demonstrable infection
How common are UTIs?
Annual incidence 10-20% women; 20% >65y have asymptomatic bacteriuria (after 65y MSU not diagnostic; clinical assessment mandatory)
How are UTIs classified?
Uncomplicated (normal renal tract structure/function)
Complicated (structural/functional abnormality of GU tract e.g. obstruction, catheter, stones, neurogenic bladder, renal transplant)
What are risk factors for UTI?
- Increased bacterial inoculation (sexual activity, UI, faecal incontinence, constipation)
- Increased binding of uropathogenic bacteria (spermicide use, decreased oestrogen, menopause)
- Decreased urine flow (dehydration, obscured urinary tract)
- Increased bacterial growth (DM, immunosuppression, obstruction, stones, catheter, renal tract malformation, pregnancy)
What are the symptoms of UTI?
Cystitis
-Frequency, dysuria, urgency, suprapubic pain, polyuria, haematuria
Acute pyelonephritis
-Fever, rigor, vomiting, loin pain/tenderness, costovertebral pain, associated cystitis symptoms, septic shock
What signs are associated with UTI?
Fever
Abdo/loin tenderness
Check for distended bladder
If vaginal discharge, consider PID
What tests can be performed?
- In non-pregnant women, if 3 or more (or 1 severe) symptom of cystitis - treat empirically without further tests
- Dipstick (use in non-pregnant women <65y with <3 symptoms)
- MSU culture (Conventional cut off >10’5 colony-forming units; use in pregnant women and those who fail to respond to empirical abx)
- Blood tests (if systemically unwell; FBC, U&E, CRP and cultures. Consider fasting glucose)
- Imaging (consider USS and referral to urology if fail to respond to treatment, recurrent UTI, pyelonephritis, unusal organism, persistent haematuria)
What organisms are usually responsible for UTI?
Anaerobes and Gram -ve bacteria from bowel and vaginal flora
E. Coli most common (75-95% community; less in hospital)
Staph saprophyticus in 5-10%
Also Proteus and klebsiella pneumonia
What may cause sterile pyuria? (inc WCC but sterile on standard culture)
TB most relevant
Recently treated UTI (or inadequately treated)
Fastidious culture requirement
Appendicitis, chlamydia
How is UTI managed in non-pregnant women?
If 3 or more (or 1 severe) symptom of cystitis, and no vaginal discharge, treat empirically with three-day course of trimethoprim or nitrofurantoin (if eGFR >30)
If first line empirical treatment fails, culture urine and treat according to abx sensitivity
In upper UTI, take culture and treat broad spectrum (e.g. co-Amoxiclav); avoid nitrofurantoin as does not reach effective concentrations in blood
How is UTI managed in pregnant women?
Get senior help
UTI assoc with preterm delivery and IUGR
Asymptomatic bacteriuria should be confirmed with second sample
Treat with abx (avoid ciprofloxacin, trimethoprim in 1st trimester, nitrofurantoin in 3rd)
Confirm erradication
