Urinary Tract Infections Lecture Review

Urinary Tract Infections (UTIs)

Concepts of Infection

• UTIs can affect any part of the urinary system.
• The urinary system includes:
  • Kidneys
  • Ureters (right and left)
  • Bladder
  • Urethra

Causes of UTIs

• Bacteria enter the urinary tract through the urethra.
• The most common bacteria causing UTIs is E. coli.

Types of UTIs

• Cystitis:
  • Affects the bladder.
  • Most common type of UTI.
• Urethritis:
  • Affects the urethra.
• Pyelonephritis:
  • Affects the kidney.
  • The most serious type of UTI.

Lower vs. Upper UTIs

• Lower UTIs:
  • Cystitis (bladder)
  • Urethritis (urethra)
• Upper UTIs:
  • Pyelonephritis (kidney, ureter)

Risk Factors for UTIs

• Biological female gender
• Sexual activity
• Certain birth control methods (diaphragms, spermicides)
• Pregnancy
• Menopausal/Hormonal changes (vaginal/urethral atrophy)
• Age-related changes (BPH - Benign Prostatic Hyperplasia in men)
• Pre-existing conditions (diabetes, kidney stones)
• Structural problems
• Poor hygiene
• Catheters
• Incomplete bladder emptying
• Recurrent UTIs

Symptoms of UTIs

• Pain or burning during urination (dysuria) due to irritation
• Urinary frequency
• Urinary urgency
• Strong or foul-smelling urine
• Lower abdominal pain
• Back or "flank pain"
• Fever/chills
• Nausea

Laboratory and Diagnostic Testing

• Urinalysis (UA, Urine dip):
  • Checks for WBCs (White Blood Cells), RBCs (Red Blood Cells), and bacteria.
• Urine culture:
  • Identifies the type-specific bacteria.
• Imaging:
  • Ultrasound (US)
  • Computed Tomography (CT) scan
  • Magnetic Resonance Imaging (MRI)
• Cystoscopy

Treatments for UTIs

• Antibiotics:
  • Trimethoprim/Sulfamethoxazole
  • Nitrofurantoin
  • Ciprofloxacin
  • Cephalexin
  • Ceftriaxone
• Increasing oral fluids (especially water)

Prevention of UTIs

• Encourage fluid intake.
• Avoid irritants (caffeine, alcohol).
• Avoid "holding" urine and fully empty the bladder.
• Practice good hygiene (females - wipe front to back).
• Empty bladder before sex.

Acute Pyelonephritis (APN)

Definition

• A bacterial infection that causes inflammation of the kidneys.
• Usually occurs from ascending infections (from the lower urinary tract).
• Most common bacteria: E. coli.
• Bacterial infection of the upper urinary tract that usually develops from a lower urinary tract infection.

Key Aspects

• Can be caused by Vesicoureteral Reflux (VUR).
• Presents with systemic symptoms.

Symptoms

• Fever
• Flank pain

Treatment

• Antibiotics

Clinical Manifestations of Acute Pyelonephritis

• Symptoms develop rapidly (<24 hours) and may include:
  • Acutely ill appearance
  • Chills
  • Fever > 38°C
  • Flank pain
  • Nausea/vomiting
  • Renal angle tenderness
  • Confusion (especially in elderly patients; may present as a change in mental status)
  • Leukocytosis (increased WBC count)
  • Pyuria (WBCs in urine)
  • Bacteriuria (bacteria in urine)
  • Symptoms of lower tract involvement:
    • Dysuria (painful urination)
    • Frequency

Diagnostic and Laboratory Testing for APN

• Urinalysis:
  • Presence of bacteria
  • WBCs (pyuria)
  • RBCs (hematuria)
• Urine culture
• Imaging:
  • CT scan
  • Ultrasound (US)
  • MRI
• Renal function tests:
  • Creatinine
  • Blood Urea Nitrogen (BUN)
  • Electrolytes
• CBC (Complete Blood Count)
• Blood cultures

Risk Factors for APN

• Urinary tract obstructions
• Compromised immunity
• Anatomical abnormalities
• Pregnancy
• Diabetes
• Urinary catheters
• Sexually active women
• Vesicoureteral Reflux (VUR)
• Age
• Previous UTIs

Treatments for APN

Uncomplicated APN:

1. Oral antibiotics:
   • Trimethoprim-sulfamethoxazole
   • Fluoroquinolones
2. Increase oral fluid intake (water)

Complicated APN:

1. IV antibiotics (broad spectrum; e.g., Cephalosporins, aminopenicillins)
2. IV fluids
   *Bacterial resistance is a concern.

Supportive Care:

1. Hydration
2. Pain management