Urinary tract infections Flashcards
What are the classic symptoms of UTI?
- Dysuria (pain, stinging or burning when passing urine)
- Suprapubic pain or discomfort
- Frequency
- Urgency
- Incontinence
- Confusion is commonly the only symptom in older more frail patients
Note: these are lower UTI symptoms
What is cystitis?
Inflammation of the bladder, which can be due to infection (bacterial cystitis) or other causes
What is pyuria?
Presence of pus cells (neutrophil polymorphs) in significant quantities in urine
Represents an inflammatory response and is supportive evidence of the presence of a UTI
What is sterile pyuria?
The clinical scenario in which urine is negative on culture but significant numbers of pus cells are present
What is acute pyelonephritis?
Infetion of the upper urinary tract involving the kidneys
How does pyelonephritis present?
- Fever
- Loin, suprapubic or back pain (bilateral or unilateral)
- Looking and feeling generally unwell
- Vomiting
- Loss of appetite
- Haematuria
- Renal angle tenderness on examination
What is chronic pyelonephritis?
What causes it?
Pathological condition with renal scarring and potentially loss of renal function
Infection may be a contributory cause but the term does not necessarily imply ongoing infection
Other factors which may contribute include diabetes, vesicle-ureteric reflux and urinary obstruction
Are UTIs more common in men or women, why?
Women as the urethra is much shorter making it easy for bacteria to get into the bladder
Where is the main source of of bacteria for UTIs?
List 3 ways this may cause a UTI
Faeces
- Normal intestinal bacteria (ie. E. coli) can reach the urethral opening from the anus
- Sexual activity can spread bacteria around the perineum
- Incontinence or poor hygiene can also contribute to development of UTIs
What is a key source of UTIs in the hospital setting?
Catheters → ‘catheter-associated UTIs’
Tend to be more significant and difficult to treat
List 4 key symptoms which will differentiate between a lower UTI and pyelonephritis
- Fever
- Loin/back pain
- Nausea/vomiting
- Renal angle tenderness on examination
List 3 things which can be detected on dipstick testibg that may be associated with a UTI?
- Nitrites → gram (-) bacteria (ie. E. coli) break down nitrates in urine to nitrites
- Leukocytes → indicates infection or other cause of inflammation (leucocyte esterase is a marker of an inflammatory response)
- RBCs → haematuria, which is a common sign of infection
Presence of all 3 on a urine dip indicate a likley UTI
Compare microscopic vs macroscopic haematuria
Microscopic → blood is identified on a urine dipstick but not seen when looking at the sample
Macroscopic → blood is visible in the urine
What on the urine dip is the most indicative of a UTI?
Nitrites (better than leukocytes)
Interparate urine dipstick findings?
- (+) for Nitrites or Leukocytes and (+) for RBC
- (-) Nitrite, (+) for Leukocytes
- (+) for Nitrites
- (-) for Nitrites, Leukocytes and RBCs
- UTI is likely - requires treatment
- UTI is equally likely to other diagnoses - only treat as UTI if there is supporting clinical evidence
- It is worth treating as a UTI
- UTI less likely - do not treat as UTI
How do we determine the causitive organism in a suspected UTI?
Why is this important
A midstream urine (MSU) sample sent for microscopy, culture and sensitivity testing
Important to determine most effective antibiotic
Compare a uncomplicated vs complicated UTI
Uncomplicated → UTI caused by typical pathogens in people with a normal urinary tract and kidney function, and no predisposing co-morbidities
Complicated → UTI with an increased likelihood of complications ie. persistent infection, treatment failure and recurrent infection
When should an MSU be sent for culture?
- Pregnant
- > 65
- Recurrent UTIs
- Atypical symptoms
- Persistent symptoms or if treatment fails
- Catheterised or have recently been catheterised
- Have risk factors for resistant or complicated UTI
- Haematuria (visible or non-visible)
List 4 causitive organisms of a UTI and highlight the most common
- Escherichia coli (E. coli - gram (-) anaerobic, rod-shaped)
- Klebsiella pneumoniae
- Enterococcus
- Pseudomonas aeruginosa
Treatment for a lower UTI in non-pregnant women?
Trimethoprim or Nitrofurantoin for 3 days
When to send a urine culture for a suspected UTI ina Non-pregnant woman?
- Aged > 65 years
- Visible or non-visible haematuria
Management for a UTI in a pregnant women who is symptomatic
- Urine culture in all cases
- Antibiotic treatment
- 1st-line: nitrofurantoin (should be avoided near term)
- 2nd-line: amoxicillin or cefalexin
Which 2 antibiotics MUST be avoided in pregnancy
Incl which trimester and why?
Trimethoprim in 1st trimester → teratogenic (but should be avoided entirely)
Nitrofurantoin in 3rd trimester → risk of neonatal haemolysis
Management of asymptomatic bacteriuria in pregnant women?
- Urine culture routinely at the first antenatal visit
- Immediate antibiotic prescription of either nitrofurantoin (avoid near term), amoxicillin or cefalexin - 7-day course
- further urine culture as a test of cure
What is the ? rationale of treating asymptomatic bacteriuria?
Significant risk of progression to acute pyelonephritis
Management of a UTI in Men?
- Immediate antibiotic prescription for 7 days
- Abx: 1st line is Trimethoprim or nitrofurantoin (unless prostatitis suspected)
Does a male with a UTI require refferal to urology?
Not routinely required for men who have had one uncomplicated lower UTI
Management of a UTI in Catherised patients
If symptomatic, should be treated with a 7-day antibiotic course
Management for a patient with signs of acute pyelonephritis?
- hospital admission should be considered
- local Abx guidelines - BNF recommends a broad-spectrum cephalosporin or a quinolone (for non-pregnant women) for 10-14 days
What may recurrent UTIs in men indicate?
May be presenting feature of Prostatitis, infection of the prostate and may be acute or chronic
