CP4-5 urinary tract infections Flashcards
What is a UTI?
When the urinary tract is invaded by a pathogenic organism
How do you diagnose a UTI?
By what symptoms the patient presents with
Why do we use cultures when a patient has a UTI?
To determine the causative organism not to diagnose
What are risk factors for a UTI?
Women
Urinary stasis
Urological instrumentation e.g. catheter
Sex
Fistulae
Congenital abnormalities
What parts of the urinary tract are classed as sterile?
Bladder, kidneys and ureter
What parts of the urinary tract are colonised?
Urethra
What flora is found in the urethra?
Perineal flora
What bacteria are commonly found in perineal flora?
Coagulase negative staphylococci
Entereobacterales
Enteric gram positive cocci
Anaerobes
What bacteria most commonly causes a UTI?
E.coli
What are 6 bacteria (other than e.coli) that can cause UTI? (In order of most common to least)
Staph saprophyticus
Proteus mirabilis
Enterococus species
Klebsiella species
Other coliforms
Pseudomonas aeruginosa
Why might results of a culture indicating a UTI be inaccurate?
Contamination due to poorly taken samples
Colonisation of catheter
Asymptomatic bacteruria
What is asymptomatic bacteriuria?
How does a patient with cystitis present?
Dysuria
Urgency and frequency of urination
Super-pubic pain or tenderness
Polyuria, nocturia, haematuria
Mainly in women
How might a patient with a catheter associated UTI present?
With a catheter or had one removed in past 48 hours
Fever
Supra-pubic tenderness
+/- dysuria, urgency/frequency of urination
Unexplained systemic symptoms like altered mental state
Why does a catheter cause UTIs?
Can be colonised (formation of bacterial biofilm) - does not always indicate infection
Manipulation/removal (particularly traumatic) can cause bacteraemia and local infection.
Antibiotic prophylaxis can be indicated in some patient groups
Why can you not use a urine dipstick test when a patient has a catheter?
As catheters aren’t sterile so will always show positive for bacteria
How do patients present with pyelonephritis?
Symptoms of lower UTI
Loin/abdominal pain or tenderness
Fever
Symptoms of systemic infection like rigours, nausea, vomiting, diarrhoea, elevated CRP and WBC
How do patients with acute bacterial prostatitis present?
Male
Lower UTI symptoms
Tender tense prostate on PR plapatuon
Acute retention
Potentially complications like micro abscesses and abscesses
What pathogens are known to cause acute bacterial prostatitis?
E.coli
Less commonly gram positive bacteria like s. Aureus and enterococcus
What are risk factors for acute bacterial prostatitis?
Abnormal anatomy e.g. cancer or BPH
Prostatic trauma/manipulation
Transrectal biopsies
How do patients with chronic prostatitis present?
Pain in and around genitalia and perineum
Lower UTI symptoms
Enlarged +/- tender prostate upon examination
What causes chronic prostatitis?
> 90% due to chronic pelvic pain syndrome if non bacterial
Bacterial = recurrent UTI with same organism or can be caused by chlamydia trachomatis
How do patients with urethritis present?
Dysuria
Frequency +/- urgency of urination
Urinary hesitance
What is an example of an STI causing urethra, symptoms?
Gonorrhoea
What causes thrush? What is a common symptom?
Thrush
Irritation and dysuria
What is urethral syndrome?
Symptoms of lower UTI without any demonstrable infection aka abacterial cystitis or frequency-dysuria syndrome
When is a patient classed as having recurrent UTIs?
> 2 infections in 6 month or >3 in a year
What are risk factors for UTIs?
Renal or bladder stones
Having sex
Post menopausal low oestrogen
Anatomical abnormalities causing stasis
What other diseases should be ruled out of a patient has recurrent UTIs?
Cancer
Prostatitis (in men)
How will a patient with an infection at their nephrostomy site present?
Fever
Pain/tenderness at site
Heamaturia or purulent discharge +/- urosepsis
What is nephrostomy?
Percutaneous drain straight into the kidney
What is an ileal conduit/urostomy?
When a short section of ileum is used to drain the ureters directly to a stoma on the anterior abdominal wall after a cystectomy (removal of the bladder)
What are symptoms of an infection or an ileal conduit/ urostomy?
Fever
Upper UTI symptoms if ascending infection
Redness, swelling and pus if para-stomal skin infection
What complications can lead to a perinephric renal abscesses?
Commonly = gram negative bacilli infection
Uncommonly = complication of renal stones or diabetes or secondary to obstruction of infected kidneys
What causes perinephric renal abscesses?
Usually gram negative bacilli
What is an intro-renal abscess? What is it associated with?
An abscess caused by haematogenous spread (unilateral, single or renal cortex) of staph aureus which can be associated with classic acute pyelonephritis of the cortex or medulla.
How will patients with urosepsis present?
Fever
Rigors
Nausea, vomiting and diarrhoea
+/- haemodynamic compromise
Raised inflammatory markers including CRP and WCC
What makes a UTI an anatomical complicated UTI?
A UTI alongside:
Structural abnormalities e.g. enlarged prostate
Calculi
Obstruction
Vesico-ureteric reflux
What makes a UTI a physiological complicated UTIs?
Pregnancy
Immunocompromise
Impaired renal failure
What makes a UTI a iatrogenic complicated UTI?
Recent instrumentation
Indwelling catheter or other prosthetic material (including stents)
What tests should be done for a UTI?
Urine culture and susceptibility testing
Inflammatory markers - monitor in severe infection
Imaging to look for stones, abscess or anatomical abnormalities in upper UTIs
When should a dipstick test be used?
As a screen to rule out lower UTIs where diagnosis is clinically dubious in women under 65
Over 3 year olds
What samples can be tested in the microbiology labs?
Urine
-mid stream
-Catheter urine
-clean catch for paediatric
-Supra-pubic aspirate
-nephrostomy or ileal conduit
Blood cultures
When should blood cultures be taken for a UTI?
If suspect pyelonephritis or severe sepsis
Before starting IV antibiotics on any patient
What is sterile pyuria?
When pus cells are (raised WCC) in urine and no organism grow with standard lab methods. A repeat sample is advised if symptoms continue.
What causes sterile pyuria?
Inhibition of bacterial growth due to antibiotics or the sample is contaminated with antiseptic
Fastidious organisms
Urinary tract inflammation
Urethritis due to STI
When should a UTI be further investigated?
If UTI in childhood
Pyelonephritis
In men
Recurrent UTIs
Red flags for cancer
What non-antimicrobial management is used to treat UTIs?
Increase fluid intake
Anti inflammatories like NSAIDs
Cranberry juice + extracts potentially
Removal of catheter if no longer indicated
Drainage of obstruction or abscess if present.
What is the criteria and antibiotic has to meet to be used for a UTI?
Gets into urine
Minimally toxic
Effective against likely organisms
Easily administered
Cheap
What are examples of antibiotics for UTIs?
For lower UTI only:
Nitrofurantoin (inadequate for systemic infection)
Pivmecillinam
Fosformycin (oral formulation)
Trimethoprim
How do you treat cystitis in women?
Self care including increased fluid +/- ibuprofen
3 days of oral antibiotics (can be delayed prescription to try self care first)
How do you treat cystitis in men?
Oral antibiotics for 7 days
How do you treat cystitis if patient has a catheter?
7 days of antibiotics
How is pyelonephritis treated empirically?
Broad action antibiotics against the likely causative pathogen
E.g. cefuroxime, aztreonam, ciprofloxacin and gentamicin
How is pyelonephritis treated directly?
With the narrowest spectrum antibiotic possible based on sensitivity results for 7-14 days depending on the antibiotic
How long does pyelonephritis need treating for.
7-14 days
How is prostatitis treated empirically?
IV pipercillin-tazobactam
IV/PO ciprofloxacin
How is prostatitis treated directly?
With IV pipercillin-tazobactam or IV/PO ciprofloxacin
Or trimethoprim or co-trimoxazole
How long is prostatitis treated for?
2-4 weeks uncles chronic bacterial prostatitis which is treated for longer
Who is treated for asymptomatic bacteruria?
Pregnant people
Infants
People who are due to have a urological procedure
Who does not require antibiotics for asymptomatic bacteruria?
Elderly patients
Catheterised patients
What lifestyle modifications are recommended for adults with confirmed recurrent UTIs?
Increased fluid intake
Review of contraception
Peeing after sex
Oestrogen replacement in post-menopausal women
