Urinary tract infection Flashcards
Presentation of UTI
dysuria, frequency and smelly urine
BUT can be unwell/failure to thrive or incontinence
Do ureters store urine?
no - constant trickle
How do the ureter enter the bladder?
at an angle
Significance of ureters entering bladder at an angle
as bladder fills up and pressure increases this closes off ureter and stops reflux of urine
4 normal urinary tract bacteriostatic propertier
prostatic secretions
anti-bacterial antibodies
free flow of urine through normal anatomy
low pH, high osmolarity and high ammonia
What part of urinary tract is sterile?
all of it apart from terminal urethra
2 commensal bacteria flora of terminal urethra
gut flora eg ecoli
skin - perineal
If a suprapubic aspirate is taken will this be sterile or not?
sterile
Is a urine specimen ever sterile?
NO -always atleast slightly contaminated by terminal urethra flora
Which part of urine will be most highly contaminated?
first few mls
Significance of MSSU
initial void discarded with most bacteria
still always present but flush out majority
How is MSSU interpreted?
microbiology - bacteria grow in log phase
dip slide method to count colonies and bacteria
time and temperature of MSSU incubation
24 hours 37 degrees
What number means an infection in culture?
10 to the power of 5
What does 10 to the power of 3/4 mean in culture?
probable infection if symptoms and 50% chance if no symptoms
What people are MSSU difficult to collect?
children and elderly
What microorganisms cause UTI?
bacteria eg ecoli
virus and fungi rare
Is route of infection in UTI ascending or descending?
almost always ascending
When is a UTI more serious?
kidney infection
List the words used for inflammation of a - bladder b - urethra c - ureters d - kidney
a - cystitis
b - urethritis
c - ureteritis
d - acute pyelonephritis
When can acute pyelonephritis become chronic pyelonephritis?
prolonged or recurrent infection
3 broad predisposing factors of UTI
urine stasis
pushing bacteria up from above
generalised predisposition to infection
2 reasons for stasis of urine
obstruction = congenital or acquired
spinal cord or brain injury
reasons for pushing bacteria up from above
female, sex, catheter
Reason for generalised predisposition to infection
diabetes
Main reason stasis or urine causes UTI
bacteria that do get higher up do not get flushed out
consequences of obstruction at urethra
urethral and bladder dilation
bilateral hydroureter and hydronephrosis
chronic renal failure
Consequences of unilateral renal pelvis obstruction
unilateral hydroureter and hydronephrosis
Consequences of obstruction of renal tract
proximal dilation
slowed urine flow –> infection
sediments form calculi –> more obstruction
triad of obstruction of renal tract
calculi, more infection and more dilation
Obstruction in children
vesicoureteric reflux
Consequences of vesicoureteric reflux
hydroureter
Common causes of renal tract obstruction in adults
women - uterine prolapse
men - BPH
tumours and calculi
Why is a spinal cord/brain injury a cause of UTI?
cannot empty bladder fully - high residual volume
no sense when to micturate - stasis of urine
Why is sexual activity a cause of UTI?
age
move bacteria up from terminal urethra
urethral back wall just infront of vagina
Why are women ore predisposed to UTI than men?
short ureter
no prostatic secretions
urethral orifice close to rectum
sexual activity - void after intercourse
pregnancy - pressure on ureters and bladder
Why is catheter risk of UTI?
move bacterial flora up
same with any urinary procedure
Why is diabetes a risk factor for UTI?
glucose in urine and poor WBC function
acute complications of UTI
sepsis and septic shock
chronic complications of UTI
chronic damage to kidneys if repeated infection
hypertension, chronic renal failure, calculi and hydronephrosis
