1. Urinary Tract Infection Flashcards
What are the three main predisposing factors for UTI’s?
- Stasis of Urine
- Pushing Bacteria up the Urethra (from below)
- Generalized predisposition to infection
What can cause the Stasis of Urine?
- Obstruction
a) Congenital - Children
b) Acquired - Adults - Spinal Cord / Brain injury
What is the pathology of Obstruction causing the Stasis of Urine?
- The Obstruction leads to proximal dilation, leading to the backlog of pressure (this can cause further dilation)
- Slowed urine flow results in bacteria not being flushed out
- Slowed urine flow results in sediment forming, which can lead to calculous (stone) formation
What is the Pathology of Spinal Cord / Brain injury causing the Stasis of Urine?
Decreased sensation (the loss of the feeling of a full bladder), so there is no knowing of when to empty the bladder
What can cause the Pushing of Bacteria up the Urethra from below?
- Sexual activity in females
2. Catheterisation
What leaves females (after sexual activity) predisposed to UTI’s?
- A short Urethra
2. The lack of Prostatic Bacteriostatic Secretion
What can cause Generalized Predisposition to Infection?
- Immunosuppression
2. Diabetes Mellitus
Why does Diabetes Mellitus leave you predisposed to UTI’s?
Due to the presence of Glucose in the Urine, as a source of energy for the Bacteria
What are the most common causative agents in UTI’s?
Commensals:
- E. Coli
- Proteus
- Klebsiella
- Enterococcus
Where can UTI’s from the Urethra spread to?
- The Bladder
- The Ureters
- The Kidneys
What is the name of the inflammatory response in the Urethra?
Urethritis
What is the name of the inflammatory response in the Bladder?
Cystitis
What is the name of the inflammatory response in the Ureter?
Ureteritis
What is the name of the inflammatory response in the Kidneys?
Acute Pyelonephritis
Note - this can become chronic if there is prolonged / recurrent infection)
What is the name of the inflammatory response in the Epididymis/Testis?
Emididymo-Orchitis
What is the main cause of Obstruction in children?
Vesicoureteric Reflux
What is Vesicoureteric Reflux?
A decreased angle of insertion into the bladder
What are the main causes of Obstruction in Males / Females
Males - Benign Prostatic Hyperplasia
Females - Uterine Prolapse
What are the Clinical Features of UTI’s?
- Dysuria
- Frequency Change
- Cloudy, Smelly Urine
- Systemic Symptoms of Infection
- Incontinence (Elderly)
- Confusion (Elderly)
- Failure to Thrive (Very Young)
What are some Complications of UTI’s?
- Sepsis
- Chronic Pyelonephritis
- Calculi Formation
- Confusion
What is Dysuria?
Painful or Difficult Urination - Like Passing Broken Glass
How does the Frequency change?
There is an increase in Urgency, due o Strangury
What is Strangury?
A condition caused by blockage / irritation of the base of the bladder - resulting in severe pain and a strong desire to urinate
Why does the Urine appear Cloudy, Smelly Urine?
Due to the infection
What systemic symptoms or infection can occur?
- Fever
- Malaise
- Chills
- Rigors
What investigations are necessary for UTI’s?
- Mid-Stream Specimen of Urine with Culture
- Urinalysis (Urine Dipstick)
- Urine Microbiology in a Laboratory
What is a Mid-Stream Specimen of Urine?
The patient voids and stops mid-stream. The next volume of urine is then taken as this sample will be void of urethral flora.
What is looked for in Urinalysis (Urine Dipstick)
- Blood in the Urine (Haematuira)
- Leukocytes in the Urine
- Protein in the Urine (Proteinuria)
- Nitrates in the Urine
What will occur in Urine Microbiology in a Laboratory?
- Microscopy and Gram Staining
2. Bacteriuria (Bacterial Culture)
Is there ever a Flase-Negative result from Bacteriuria (Bacterial Culture)?
No
What are the results from Bacteriuria?
- <10^3 indicates that there is usually no infection
- 10^3-10^4 indicates infection is probable is probable if symptomatic / 50% if asymptomatic
- > 10^5 indicates infection
What is the treatment of UTI’s?
- Identify the infecting organsims and treat with:
a) Fluids
b) Antibiotics
c) Repetative voiding (every 2-3 hours
Identify the Predisposing factors and treat them:
a) Abnormal Urinary Tract - remove stones / control diabetes
b) Reflux Nephropathy - surgery (common in children)
c) Indwelling catheters - replace catheter / antibiotics
d) Chronic Pyelonephritis
