Urinary tract infection pathology Flashcards
what is the presentation of a uti?
dysuria
frequency
smelly urine
why would a uti occur in yound children versus an eldery patient?
young - unwell failure to thrive
old - incontinent
renal blood flow is what percent of cardiac output?
20-25% of cardiac output
does urine output change with oral intake of fluid?
yes resorption of fluid is diminished if increase fluid intake increased urine output
do ureters store urine?
no have a continuous trickle of urine
how to ureters enter the bladder?
at an angle
increasing pressure from the bladder as it fills closes off ureter and stops reflux of urine
what are bacteriostatic properties od the urinary tract?
Free flow of urine through normal anatomy – assumes drinking enough fluids
Low pH, high osmolality, and high ammonia (NH3) content of normal urine
prostatic secretions are bacteriostatic
anti-bacterial antibodies
what is the exeption of the urinary tract that is sterile?
urinary tract exept terminal urethra
what will flush out many terminal urethral flora bacteria?
initial voiding
what are different types of urine specimin for culture?
- initial urine
- collect after initial void, patient voids stops mid stream discards urine then collects next volume (MSSU)
describe midstram specimin urine?
urethra flora will alwats grow in culture
no such thing as negative result
microbiology for culture under set conditions
bacteria multiply in log phase growth
quick way - dipslide method
what is the chance of contamination with MSSU culture?
105 per ml - <1:100 chance of contamination if asymptomatic – ie 99 times out of 100, 105 bacteria per ml represents infection – if specimen = MSSU
MSSU culture – 103 104
infection sometimes
if symptomatic probable that there is an infection
MSSU culture – 103 104 = 50 % chance of infection if no symptoms
MSSU culture – <103 =
ussually no infection
when is mssu difficult to collect?
in yound children and the elderly