Question

Case study: 25 year old female comes into the clinic with complaints of dysuria for past 3 days which has become worse. She admits to urgency and frequency. On physical exam she has lower mid abdominal tenderness with palpation and no CVA tenderness. She is diagnosed with a lower urinary tract infection. 1. Please identify her symptoms and explain the mechanisms that cause each one?

Answer 1

URINARY TRACT INFECTION

A urinary tract infection is an infection involving the organs that produce urine and carry it out of the body. These structures include the kidneys, ureters (long, slender tubes connecting the kidneys with the bladder), bladder and urethra. Doctors often divide urinary tract infections into two types, lower tract infections and upper tract infections:

Lower Urinary tract infections — Infection of the bladder is called cystitis (bladder infection). Bacteria normally found in the intestine are the main cause of lower urinary tract infections.

Risk factors for UTIS Factors resulting in compromise of normal host defences to bacterial colonization are an important step in the pathogenesis of UTIS. Risk factors latrogenic/drugs Behavioural Anatomic/physiologic Genetic • Indwelling catheter • Antibiotic use • Spermicides • Voiding dysfunction • Frequent or recent sexual intercourse • Vesicoureteral reflux • Female sex • Pregnancy • Familial tendency Susceptible uroepithelial cells • Vaginal mucus properties Indwelling foley catheters provide an ascending route for perineal bacteria to enter the bladder. Recent antibiotic use disrupts the normal bacterial flora at the vaginal introitus, allowing uropathogens leg E. coli) to colonize Spermicides cause irritation and attachment sites for E có. Voiding dysfunction causes increased post-void residual urine volumes, which allows more time for bacterial proliferation. Frequent or recent sexual intercourse may introduce bacteria into the urinary tract Vesicoureteral reflux causes urinary retention and allows more time for bacterial growth. The retrograde flow also allows bacteria to ascend to the kidneys. Females have a short urethra (4cm vs 25 cm in males). Pregnancy results in progesterone-mediated smooth muscle relaxation to the bladder and ureters, and compression of the ureters by the uterus. Both result in urinary retention for increased bacterial growth. UTI occurrence tends to cluster in families. Susceptible uroepithelial cells secrete less A, which is the main humoral defence mechanism at the physiologic mucosa. Properties of vaginal mucus may allow E. coli binding more readily

Symptoms

Lower and upper tract infections can cause one or more of the following symptoms:

• · Unusually frequent urination
• · An intense urge to urinate
• · Pain, discomfort or a burning sensation during urination
• · Pain, pressure or tenderness in the area of the bladder (midline, above or near the pubic area)
• · Urine that looks cloudy, or smells foul or unusually strong
• · Fever, with or without chills
• · Nausea and vomiting
• · Pain in the side or mid-to-upper back
• · Waking from sleep to pass urine
• Bedwetting in a person who has usually been dry at night

• SYMPTOMS AND MECHANISM OF SYMPTOMS

Symptom	Corresponding sign	Mechanism
Dysuria		Due to acute inflammation of the bladder, resulting in discomfort upon contraction during voiding.
Frequency and urgency		Reduced bladder capacity due to inflammatory edema causing decreased compliance and pain due to bladder distension.
Hematuria		Irritated, edematous urinary tract bleeding with voiding.
Suprapubic tenderness		Due to palpation and compression of an inflamed, edematous bladder.
Chills and sweats	Fever	Inflammatory cascade resulting in a febrile response.
Flank pain (may radiate to groin, often dull and constant)	Costovertebral angle (CVA) tenderness	Sudden renal edema, resulting in increased pressure and capsular distension.

The most common bacterial causes of UTI are the same bacteria that colonize the gut and they enter the urinary tract following colonization of the peri-urethral area. Once within the bladder, bacteria may then multiply and ascend the ureters to cause upper UTI..