pathology of UTI

Question 1

How does UTI commonly present

Answer 1

Dysuria but specifically in the suprapubic region - pain on micturition
Frequency
Urine with weird smell

Question 2

What is the renal blood flow

Answer 2

1200mls/minute - 20-25% of cardiac output

Question 3

What happens to the urine output if fluid intake increases

Answer 3

urine output increases

Question 4

How do ureters work

Answer 4

They do not store urine but urine instead continuously trickles down into the bladder

Question 5

Why do ureters enter the bladder at an angle

Answer 5

To reduce the back flow of urine

Question 6

What happens when the bladder pressure increases during filling with regards to the ureter

Answer 6

The ureter is closed off and this stops reflux back into the ureter

Question 7

What does bacteriostatic mean

Answer 7

helps to stop or prevent bacteria flourishing

Question 8

What are bacteriostatic properties of the normal urinary tract

Answer 8

Free flow of urine - assuming fluid intake is good
Low PH, high osmolarity and high ammonia content of urine
Prostatic secretions in men are bacteriostatic
All antibacterial antibodies

Question 9

What part of the urinary tract is not sterile

Answer 9

Terminal urethra - contains flora from the gut and skin

Question 10

Describe when urine becomes contaminated passing through the urinary system

Answer 10

The urine is sterile until it gets to the terminal urethra where it becomes contaminated

Question 11

How are urine samples taken to avoid the initial contamination at the terminal urethra

Answer 11

Mid-stream specimen of urine

Patient is asked to void and then stop mid-stream, and then start voiding again which is what is sampled

The initial void flushes out a lot of the bacteria - mid-stream specimen will still have some bacteria but a lot less than the first void

Question 12

What number of bacteria on culture usually means infection

Answer 12

10 to the power of 5 - when it is this high, it is less than 1% chance of the bacteria being the urethral bacterial contamination

Question 13

What does a MSSU culture of 10 to the 3 or 4 mean

Answer 13

there is a 50% chance of infection without symptoms

Question 14

What does a MSSU culture of 10 to the 3 or 4 mean with symptoms

Answer 14

probable infection

Question 15

What does a MSSU culture < 10 to the power of 3 mean

Answer 15

Usually no infection

Question 16

What are difficulties in MSSU

Answer 16

Children and elderly may struggle to stop and start urinating

Question 17

What is the micro-organisms which most commonly cause UTI

Answer 17

E.coli

Question 18

What is the most common route of infection in UTI

Answer 18

Ascending - perineal bacteria in the urethra begins to ascend upwards

Question 19

What do UTI’s lead to and name the condition for each part of the urinary system

Answer 19

Inflammation
Urethra - urethritis
Bladder - cystitis
Ureter - ureteritis
Kidney - acute pyelonephritis or chronic pyelonephritis if the infection is recurrent or prolonged

Question 20

What are predisposing factors to UTI

Answer 20

stasis of urine
Pushing bacteria from the terminal urethra
General weak immune system so predisposed to infection

Question 21

What causes stasis of urine

Answer 21

Obstruction - congenital or acquired
Loss of sensation of the bladder - spinal cord/brain injury - loss of sensation can mean bladder can’t respond when the bladder is full

Question 22

What causes bacteria to be pushed up from the urethra

Answer 22

Sexual activity in females
Catheterisation and other urological procedures

Question 23

What is hyronephrosis

Answer 23

Dilatation of the kidney which is usually caused by the back up of urine

Question 24

What are the consequences of obstruction

Answer 24

Proximal dilataion

Slowed urine flow therefore cannot flush out bacteria and therefore infections occur

Slowed urine flow leads to sediments forming which can lead to calculous(stone) formation which can cause more obstruction and lead to more infections

Question 25

What is the most important example of obstruction in children

Answer 25

Vesicoureteral reflux where urine moves from the bladder back up to the kidney due to decreased angulation of the ureters in the insertion into the bladder

Question 26

What are the most common causes of obstruction in adults

Answer 26

Men - BPH - benign prostatic hyperplasia - increase in the number of prostate cells

Women - uterine prolapse

In both genders, tumours and calculi are common causes of obstruction

Question 27

How does the brain know when the bladder is full

Answer 27

There are stretch receptors on the bladder which sense the fullness of the bladder - they run back to the brain and result in the external sphincter relaxing and detrusor muscle contracting which causes micturition

Question 28

Why does sexual activity move urethral flora up the urinary tract

Answer 28

The back wall of the urethra is in front of the vagina

Question 29

Why are females at more risk of UTI then males

Answer 29

Females have a:
Shorter urethra
No prostatic secretion (bacteriostatic secretion)
Their rectum is close to the urethral orifice
Sexual activity - helps if void after intercourse
Pregnancy as it puts pressure on the ureters and bladder

Question 30

What can help to prevent UTI after intercourse

Answer 30

Voiding after intercours

Question 31

Why can diabetes predispose UTI

Answer 31

Glucose in the urine which the bacteria can feed and thrive on and weaker functioning white blood cells

Question 32

What is an acute complication of UTI

Answer 32

Severe sepsis and septic shock

Question 33

What are chronic complications of UTI

Answer 33

Chronic pyelonephritis if there is repeated UTI due to the hypertension caused by the infection - this will harm the kidneys and another infection would lead to chronic kidney failure

Calculi causes obstruction which leads to hydronephrosis and then hypertension and then chronic renal failure