Presentation of Diseases of the Kidney and Urinary Tract Flashcards
What is dysuria?
Pain on micturition (peeing)
Describe the UTI Presentation
- Dysuria, frequency, smelly urine
- Very young - unwell, failure to thrive
- Very old - incontinence
How does urine output change in with oral intake of fluids?
Resorption of fluid is diminished if increase fluid intake -> increased urine output
(drink more –> pee more)
Do ureters store urine?
No, only transfer urine from kidneys to bladder
Where do the ureters end?
At the trigone of the bladder, at an angle; angle to prevent reflux of urine up the ureters
What are two mechanisms to prevent reflux of urine up the ureters?
- Enter bladder at an angle
* Increasing pressure from bladder as it fills with urine, closes off ureter and stops reflux
Describe the bacteriostatic properties (prevents proliferation) on 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
Describe the bacteria present along the renal tract
Urinary tract is sterile up until the terminal urethra, which is NOT sterile due to bacteria from skin moving in
What would a suprapubic aspirate of the normal renal tract show?
Aspiration and the culture –> is sterile in normal conditions
What is a problem with using urinated specimen to culture for bacteria?
Will always be contaminated by terminal urethral flora
How can urinated specimens be used to culture bacteria without being contaminated?
Use initial voiding (first pee) to flush out terminal floral bacteria and stop mid stream
Then collect next volume of urine = MSSU (mid-stream specimen of urine)
Urethral flora diminished but always present and will always grow in culture
What is the the difficulty with interpreting results with an MSSU?
Need to be able to distinguish contamination of terminal urethral flora from a real infection
Describe the results of an MSSU
- Bacteria multiply in log phase growth
- 10^5 regarded as infection (even if asymptomatic)
- 10^3-4 infection sometime, esp. if has symptoms (50% chance if no symptoms)
- < 10^3 usually no infection
- Not an absolute guide, need an overall picture of patient and if they have symptoms
What groups of people are hard to collect an MSSU sample from?
Eldery (incontinent) and young (hard to stop mid-stream)
Name microorganisms that can cause UTI
- Bacteria mostly - esp. E. coli
* Viral infection rare
What is the most common route of infection?
Ascending:
Travels upwards from the terminal urethral flora
Very rare to be haematogenous spread
Name the different inflammatory responses that infection can cause
- Urethra - urethritis
- Bladder – cystitis
- Ureter – ureteritis
- Kidney – acute pyelonephritis
Not always indicative of infection
What can occur after a recurrent/prolonged infection in the kidney?
Chronic pyelonephritis
What are predisposing factors for UTIs?
- Stasis of urine
- Pushing bacteria up urethra from below
- Generalised predisposition to infection
Name two causes of stasis of urine?
- Obstruction - congenital or acquired
* Loss of sensation of full bladder - spinal cord/brain injury
Name two causes of pushing bacteria up urethra from below?
- Sexual activity in females
* Catheterisation (and there urological procedures)
Name a condition which can predispose a person to an infection
Diabetes - macrophages don’t work as well in hypoglycaemia and high Glc in urine provides better conditions for bacteria to proliferate
How does stasis of urine cause a UTI?
Bacteria that do get higher up urinary tract do not get flushed out
What are the features of an obstruction?
- Upper urethral and bladder dilation above obstruction
- Bilateral hydroureter (dilation of ureter)
- Bilateral hydronephrosis (water in kidney)
Most distal the obstruction, the worse effects will be -> bilateral effect
If at level of renal pelvis -> one side only
