Pathology of Urinary Tract Infections Flashcards
What is the presentation of UTI?
- Dysuria (pain on micturition), frequency, smelly urine
- But in very young
- Unwell, failure to thrive
- In very old
- Incontinence, off their feet
What does UTI stand for?
Urinary tract infection
What is the medical term for pain on micturition?
Dysuria
What percentage of cardiac output is renal blood flow?
20-25%
What does CO stand for?
Cardiac output
What can urine output vary with?
Urine output changes with oral intake of fluids:
- Resorption of fluid is diminished if increase fluid intake causing increased urine output
Do the uterters have continuous trickle of urine or do they store urine?
Ureters have continuous trickle of urine, they do not store urine and they enter the bladder at an angle
Do the ureters enter the bladder perpendicular or at an angle?
At an angle
What happens to the ureters as the bladder fills?
They increase pressure of bladder as it fills, closing off ureter and stops reflux of urine
So the flow of urine is a one way continuous flow until the bladder is full
What are some bacteriostatic properties of the urinary tract?
- Free flow of urine through normal anatomy
- Low pH, high osmolarity and high ammonia (NH3) content of normal urine
- Prostatic secretions are bacteriostatic (bacteriostatic agent is a biological or chemical agent that stop bacteria from reproducing)
- Anti-bacterial antibodies
What is a bacteriostatic agent?
A biological or chemical agent that stop bacteria from reproducing
Is the urinary tract sterile or non-sterile?
The whole urinary tract, except for the terminal urethra, is sterile
Do urinated specimen contain any bacteria?
Urinated specimen is always contaminated by terminal urethra flora
Initial voiding will flush out many terminal urethral floral bacteria
Before taking a urine sample, what should be done to flush out many terminal urethral floral bacteria?
Initial voiding will flush out many terminal urethral floral bacteria
How is a urine sample collected without the contamintion of flora?
Initial urine is heavily contaminated, so collect after initial void:
- Patient voids and stops mid-stream, discarding urine then collects next volume of urine
- Known as mid-stream specimen of urine (MSSU)
What does MSSU stand for?
Mid-stream specimen of urine
What is the kind of urine sample known as where the patient voids first to get rid of a lot of flora bacteria?
Mid-stream specimen of urine (MSSU)
In MSSU is the urethral flora present?
In a MSSU the urethral flora is diminished but always present, and will then grow in culture:
- Therefore is no such thing as a negative result
What is a quick method of performing MSSU culture?
Quick way to perform MSSU culture is the dip slide method (but usually send for formal microbiology culture
How is a urine sample normally analysed?
Formal microbiology culture, but sometimes dip slide method can be performed which is quicker
What kind of growth do bacteria display?
Multiply in log phase growth
What are the boundaries of amount of bacteria and likelyhood of infection in MSSU?
- 105/ml is usually infection
- <1/100 chance of contamination if asymptomatic
- 103 to 104/ml is an infection sometimes
- Probable infection if have symptoms
- 50% chance of infection if no symptoms
- <103 usually means no infection
What does a bacteria concentration of 105 normally indicate?
- 105/ml is usually infection
- <1/100 chance of contamination if asymptomatic