Presentation of Diseases of the Kidney and Urinary Tract

Question 1

What is dysuria?

Answer 1

Pain on micturition (peeing)

Question 2

Describe the UTI Presentation

Answer 2

• Dysuria, frequency, smelly urine
• Very young - unwell, failure to thrive
• Very old - incontinence

Question 3

How does urine output change in with oral intake of fluids?

Answer 3

Resorption of fluid is diminished if increase fluid intake -> increased urine output

(drink more –> pee more)

Question 4

Do ureters store urine?

Answer 4

No, only transfer urine from kidneys to bladder

Question 5

Where do the ureters end?

Answer 5

At the trigone of the bladder, at an angle; angle to prevent reflux of urine up the ureters

Question 6

What are two mechanisms to prevent reflux of urine up the ureters?

Answer 6

• Enter bladder at an angle

* Increasing pressure from bladder as it fills with urine, closes off ureter and stops reflux

Question 7

Describe the bacteriostatic properties (prevents proliferation) on the urinary tract?

Answer 7

• 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

Question 8

Describe the bacteria present along the renal tract

Answer 8

Urinary tract is sterile up until the terminal urethra, which is NOT sterile due to bacteria from skin moving in

Question 9

What would a suprapubic aspirate of the normal renal tract show?

Answer 9

Aspiration and the culture –> is sterile in normal conditions

Question 10

What is a problem with using urinated specimen to culture for bacteria?

Answer 10

Will always be contaminated by terminal urethral flora

Question 11

How can urinated specimens be used to culture bacteria without being contaminated?

Answer 11

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

Question 12

What is the the difficulty with interpreting results with an MSSU?

Answer 12

Need to be able to distinguish contamination of terminal urethral flora from a real infection

Question 13

Describe the results of an MSSU

Answer 13

• 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

Question 14

What groups of people are hard to collect an MSSU sample from?

Answer 14

Eldery (incontinent) and young (hard to stop mid-stream)

Question 15

Name microorganisms that can cause UTI

Answer 15

• Bacteria mostly - esp. E. coli

* Viral infection rare

Question 16

What is the most common route of infection?

Answer 16

Ascending:
Travels upwards from the terminal urethral flora

Very rare to be haematogenous spread

Question 17

Name the different inflammatory responses that infection can cause

Answer 17

• Urethra - urethritis
• Bladder – cystitis
• Ureter – ureteritis
• Kidney – acute pyelonephritis

Not always indicative of infection

Question 18

What can occur after a recurrent/prolonged infection in the kidney?

Answer 18

Chronic pyelonephritis

Question 19

What are predisposing factors for UTIs?

Answer 19

• Stasis of urine
• Pushing bacteria up urethra from below
• Generalised predisposition to infection

Question 20

Name two causes of stasis of urine?

Answer 20

• Obstruction - congenital or acquired

* Loss of sensation of full bladder - spinal cord/brain injury

Question 21

Name two causes of pushing bacteria up urethra from below?

Answer 21

• Sexual activity in females

* Catheterisation (and there urological procedures)

Question 22

Name a condition which can predispose a person to an infection

Answer 22

Diabetes - macrophages don’t work as well in hypoglycaemia and high Glc in urine provides better conditions for bacteria to proliferate

Question 23

How does stasis of urine cause a UTI?

Answer 23

Bacteria that do get higher up urinary tract do not get flushed out

Question 24

What are the features of an obstruction?

Answer 24

• 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

Question 25

What is are the features of a distal obstruction?

Answer 25

Prolonged bladder dilatation, bilateral hydroureter and bilateral hydronephrosis –> chronic renal failure

Question 26

What is are the features of an obstruction at the level of the renal pelvis?

Answer 26

Unilateral hydroureter and unilateral hydronephrisis –> renal failure

Question 27

What are the consequences of obstruction?

Answer 27

• Proximal dilatation
• Slowed urine flow -> cannot flush out bacteria -> infection
• Slower urine flow -> sediment form -> calculous (stone) formation -> obstruction (more dilatation, more infections and calculous formed)

Question 28

How do calculi form?

Answer 28

Bacterial infection predispose calculous formation

Infection -> calculi -> obstruction -> (loop back to infection)

Question 29

How does an obstruction present as in children?

Answer 29

• Numerour renal tract abnormalities
• Always investigate at 1st presentation and send to paed surgeon
• Most important - vesicoureteric reflux

Question 30

What is the vesicoureteric reflux?

Answer 30

Decreased anglulation of the ureter as it enters into bladder –> this causes reflux of urine into ureter with hydroureter

Question 31

What are common causes of obstruction in adults?

Answer 31

• Men – Benign Prostatic Hyperplasia (not a tumour) of prostate – enlargement causing functional and anatomical obstruction
• Women – uterine prolapse
• Both sexes – tumours and calculi

Question 32

How can a spinal cord/brain injury predispose a person to stasis of urine and then UTI?

Answer 32

Decreased sensation -> no sense of when to micturate and do not know to empty bladder completely -> leave urine in bladder (high residual volume) -> stasis of urine -> bacteria able to proliferate

Question 33

How does sexual activity cause UTIs?

Answer 33

In females sexual activity tends to move lower urethral flora up the tract (back wall of urethra is just in front of vagina)

Question 34

How are females predisposed to contracting UTIs?

Answer 34

• Short urethra
• Lack of prostatic bacteriostatic secretion
• Closeness of urethral orifice to rectum
• Sexual activity – (helps if void after intercourse)
• Pregnancy – pressure on ureters and bladder causing stasis

Question 35

How do catheters and other urological procedures cause UTIs?

Answer 35

Any instrumentation of urinary tract tends to move lower urethral flora up the tract

Try and remove bacteria at terminal urethra first

Question 36

What conditions can predispose a person to infection?

Answer 36

Glucose in urine

Poor function of WBC

Question 37

Are UTIs in children concerning?

Answer 37

Yes, can have high BP, bilateratel hydronephrosus, chronic renal failure if untreated

Question 38

Are UTIs in girls with clear sexual history concerning?

Answer 38

Not was much - maybe take urine culture and if it continues do more tests

Could be abnormality with tract

Question 39

Are UTIs in girls no sexual history within 6 months concerning?

Answer 39

Yes

Question 40

What are the acute complications of a UTI?

Answer 40

Severe sepsis and septic shock

Question 41

What are the chronic complications of a UTI?

Answer 41

• Chronic damage to kidneys if repeated infections (chronic pyelonephritis) -> hypertension, chronic renal failure
• Calculi -> obstruction -> Hydronephrosis -> hypertension, chronic renal failure