Acute Pyelonephritis Lecture Notes

Introduction

Acute Pyelonephritis: Inflammation of the kidney, develops quickly due to bacterial infection.
- "Pyelo-": Pelvis
- "Neph-": Kidney
- "-itis": Inflammation

UTI: Infection of any part of the urinary tract.
- Upper Portion: Kidneys and ureters
- Lower Portion: Bladder and urethra
Acute Pyelonephritis: Type of upper UTI.

Ascending Infection:
- Bacteria start in urethra/bladder (lower UTI) and move up to kidney.
Risk Factors:
- Female sex, sexual intercourse, indwelling catheters
- Diabetes mellitus, urinary tract obstruction
- Vesicoureteral Reflux (VUR): Urine moves backward in the urinary tract.
  - Primary congenital defect or bladder outlet obstruction.
  - Urinary stasis promotes bacterial colonization.
Common Organisms: E. coli, Proteus species, Enterobacter species
Hematogenous Infection (less common)
- Spread through bloodstream (septicemia, bacteremia, infective endocarditis)
- Organisms: Staphylococcus species, E. coli

Unilateral infection: Affects one kidney.
Bacteria adhere to renal epithelium of tubules, trigger inflammation.
Immune Response:
- Chemokines attract neutrophils to renal interstitium.
- White blood cells excreted in urine (white blood cell casts).
- Leukocytosis in blood.
Symptoms:
- Systemic: Fevers, chills, nausea, vomiting
- Local: Flank pain at costovertebral angle

Diagnosis:
- Presence of white blood cells or casts in urine.
- Systemic symptoms differentiate from lower UTI.
Treatment:
- Antibiotics and hydration.

Renal Abscess: Possible complication.
Recurrent Infections:
- Chronic pyelonephritis and papillary necrosis.
- Affects kidney function adversely.

Acute pyelonephritis is a bacterial infection of the upper urinary tract often resulting from a lower UTI.
Symptoms include fevers and flank pain, treated with antibiotics.

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