Lecture 18 - UTIs Flashcards
What is considered a lower urinary tract infection?
Infection of the bladder or urethra
What is considered an upper urinary tract infection?
Infection of the ureters or kidneys
What is cystitis?
Infection of the bladder
What is pyelonephritis?
Infection of the kidneys
What adaptations does the urinary tract have against bacterial colonisation?
Emptying of bladder in micturition (flushes bacteria)
Vesico-ureteral valves (flap sitting over entrance of ureter into bladder preventing urine backflow)
Immunological factors
Mucosal barriers
Urine acidity
What are some risk factors for developing a UTI?
Female
Obstructive causes
Neurological conditions affecting bladder emptying
Pregnancy
Abnormal renal tract
Impaired host defence
Why is being female a risk factor for a UTI?
Shorter urethra and shorter distance from rectum/anus
Shorter distance for bacteria to travel
Why is having obstructive pathology a risk for developing a UTI?
Stasis of urine occurs so reduced ability to clear bladder
Why is having neurological conditions affecting bladder emptying like MS or stroke a risk for developing a UTI?
Ineffective emptying of bladder leads to stasis of urine
Why is pregnancy a risk factor for a UTI?
Uterus can compress bladder
Muscles of ureters relax/dilate leading to stasis of urine
Why is having an abnormal a renal tract and having an impaired host defence a risk for UTIs?
Vesicles-ureteric reflux may occur allowing back flow of urine
DM or immunosuppression increases infection risk
Why does prevelance in UTIs in men drastically go up at around ages 50-60?
Men usually start to get prostate issues at this age
What is the main causative organism for a UTI?
Gram negatives:
Escherichia coli
How does Escherichia coli cause damage during infection?
Flagella allow it to move
Pili allow it to attach
Then it makes toxins that damage host membranes and causes renal damage
What are the signs and symptoms of cystitis (a lower UTI)?
Dysuria (painful voiding)
Cloudy urine
Nocturia or frequency
Urgency
Suprapubic tenderness
Mild pyrexia
What are the signs and symptoms of pyelonephritis (an upper UTI)?
High fever
Rigours
Loin pain and tenderness
Nausea and vomitting
Haematuria
Symptoms of cystitis
What are some other causes of dysuria that’s not a UTI?
STIs
Post sexual intercourse
Contact with irritants
Symptoms of menopause, atrophic vaginitis or vaginal atrophy
What is considered an uncomplicated UTI in women?
Infection by a usual organism in a patient with a normal urinary tract and normal urinary function `
Why is the male defintion of an uncomplicated UTI different to women?
Men don’t normally get UTIs till old
So any male UTI is considered a COMPLICATED UTI
What is considered a complicated UTI in women?
A UTI where there are factors that predispose to persistent infection, recurrent i nfection or treatment failure:
Impaired renal function
Suspected pyelonephritis
Impaired host defence
Virulent organism (staph a)
Abnomral urinary tract
When is a urine culture taken with UTIs?
When UTI is considered complicated
When are urine dipsticks also used to help diagnose a UTI?
When patients have 1 of the following:
Dysuria
New nocturia
Cloudy urine
What patients are urine dipsticks not useful for diagnosing a UTI?
Older than 65
Catheterised
What is the causative organism if the urine dipstick is NEGATIVE for nitrites but postive for LE (leukocyte esterase)?
Staphylococcus saprophyticus
