Learning Objectives - UTI Flashcards
Clinical Manifestations of Lower UTIs (Cystitis)
Dysuria (Painfuly urination)
Increased Urinary Frequency + Urgency
Suprapubic Discomfort
Possible Haematuria (Blood in Urine)
Clinical Manifestations of Upper UTIs (pyelonephritis)
Systemic symptoms
Fever
Chills
Flank Pain
Nausea
Vomiting
Malaise
Definition of Lower UTI
Infection of the bladder (cystitis)
Definition of Upper UTI
Infection of ureters and Kidneys (Pyelonephritis)
Urinary Tract Infection (UTI) definitions
An infection occurring in any part of the urinary system: kidneys, ureters, bladder or urethra
Uncomplicated UTI definitions
Refers to infection in a structurally and neurologically normal urinary tract of adult females
- Premenopausal
-Non-pregnant with no known relevant anatomical + functional abnormalities within the urinary tract or comorbidities
Uncomplicated UTI occur in which demographic
Premenopausal
Non pregnant women with no known relevant anatomical + functional abnormalities within the urinary tract or comorbidities
Complicated UTIs definition
An infection of the urinary tract in the presence of factors that can predispose patient to either persistent or relapsing infection(s)
Complicated UTIs include which demographic
- Male (treat for minimum 7 days)
- Pregnant Women
- Post menopausal females
- Children
- Diabetes
- Foreign body (catheter, other)
- Obstruction
- Immunosuppression
- Renal failure
- Renal Transplantation
- Urinary Retention - Neurological
Asymptomatic bacteriuria
Considerable bacteriuria in a patient without symptoms. No adverse consequences + service no benefit from antibiotic therapy
Problems associated with urinary tract infections in non-pregnant women
Recurrent Infections
Renal Damage
Urosepsis
Problems associated with Urinary Tract Infections in pregnant women
Increased risk of pre-term labour
Low birth weight infants
Pathophysiology of Urinary Tract Infections
Ascending bacterial infection; pathogens enter the urinary tract via the urethra and colonise the bladder
Pathophysiology of urinary tract infections. What factors facilitate colonisation?
Bacterial virulence factors, such as adhesions + biofilm formation facilitate colonisation + persistence
Pathophysiology of urinary tract infections. What are the host defences?
Urinary flow
Mucosal Immunity
Antimicrobial properties of urine
Epidemiology of UTIs in Women
Shorter female urethra (4cm vs 20 in men)
Proximity to the anus
Hormonal changes
Sexual activity
How does age affect the incidence of UTIs? Women
More common in sexually active young women and increase post-menopause due to changes in vaginal flora + oestrogen levels
How does age affect the incidence of UTIs? Men
Prostate enlargement can lead to urinary retention -> increased infection risk
Epidemiology of UTIs Men Over 50
UTIs in men are rare but increase in incidence after age 50 due to prostate enlargement
Common Causative Pathogens
E.coli (70%-95% of cases) of uncomplicated UTIs
Staphylococcus saprophyticus
Klebsiella pneumoniae
Causative pathogens in Hospital-Acquired infections
May involves more resistant organisms :
Pseudomonas aeruginosa
Enterococcus species
What virulence factors enable uropathogenic E.coli to cause UTIs?
E.coli has adhesins, such as P fimbriae, to attach to the bladder lining. It produces toxins like hemolysin; damages host tissues. Biofilms protecting it from the immune response + antibiotics
How do uncomplicated and complicated UTIs differ?
Uncomplicated UTIs occur in structurally normal urinary tract, typically in healthy non pregnant women. Complicated UTIs involve underlying conditions like anatomical abnormalities, urinary retention or immunosuppression
Clinical Decision rules for differentiating UTIs?
Symptoms assessment
History
Diagnostic tests
Laboratory tests: Urine Dipstick
Urine Culture
Risk factors for Minor UTIs?
Female sex
Sexual activity
Use of spermicides
History of previous UTIs
Frequent sexual intercourse
Risk factors of Major UTIs or complicated infections
Structural abnormalities (e.g kidney stones)
Immunocompromised states
Pregnancy
Diabetes
Use of in dwelling catheters
Men x>50 prostatic hypertrophy
First-Line Treatment for Uncomplicated UTIs in Non-Pregnant Women
Nitrofurantoin: 100mg modified-release BD for 3 days (if estimated glomerular filtration rate >45ml/min)
Alternative First-Line Treatment for Uncomplicated UTIs in Non-pregnant Women.
If nitrofurantoin is unsuitable
Trimethoprim: 200mg BD for 3 days (if low risk of resistance)
Second-Line Treatment for Uncomplicated UTIs in Non-Pregnant Women
Pivmecillinam: 400mg initial dose, then 200mg TDS for a total of three days
Fosfomycin: 3g single dose sachet
Treatment for Uncomplicated UTIs in Pregnant Women
Nitrofurantoin: 100mg modified-release BD for 7 days (avoid at term)
Amoxicillin: 500mg TDS for 7 days (if culture results confirm susceptibility)
Cefalexin: 500mg BD for 7 days
Treatment for Uncomplicated UTIs in Men
Nitrofurantoin: 100mg modified-release BD for 7 days
Trimethoprim: 200mg BD for 7 days
Treatment for Complicated UTIs
Treatment should be guided by urine culture + sensitivity results. Options may include:
Ciprofloxacin: 500mg BD for 7 days
Co-amoxiclav: 500/125mg TDS for 7 days
Trimethoprim: 200mg BD for 14 days (if culture results confirm susceptibility.)
Treatment for Catheter- Associated UTIs
Nitrofurantoin: 100mg modified release BD for 7 days ( if no upper UTI symptoms)
Trimethoprim: 200mg BD for 7 days (if no upper UTI symptoms
Cefalexin: 500mg BD/TDS for 7 days (if upper UTI symptoms)
Treatment for Recurrent UTIs
Antibiotic Prophylaxis: e.g Nitrofurantoin 50 mg or 100mg at night for 6 months with regular review
Self-care measures: Personal hygiene measures; increased fluid intake + post-coital voiding
Treatment of Asymptomatic Bacteriuria in Pregnancy
Nitrofurantoin: 100mg modified release BD for 7 days (avoid at term)
Amoxicillin: 500mg TDS for 7 days (if culture results confirm susceptibility)
Cefalexin: 500mg BD for 7 days Trimethoprim
