Tubular & Interstitial Diseases

Question 1

List some of the main causes of Tubular & Interstitial Diseases

Answer 1

Question 3

Acute Tubular Necrosis

Answer 3

Acute injury to renal tubules, causing cell death (necrosis)…..acute renal failure

2 major causes: ischemic & toxic

ARF: intrinsic & pre-renal cause

• acute decline in GFR,
• oliguria/anuria,
• serum BUN & Creatinine increased

Question 4

Acute Tubular Necrosis (Clinical Course)

Answer 4

Question 5

Acute Tubular Necrosis (Pathogenesis)

Answer 5

Question 6

Acute Tubular Necrosis (Diagnosis)

Answer 6

Clinical history / lab & urinary sediment

1- Ischemic insult:

• Hypotension
• Vasodilatory (septic shock)systemic infection
• Hemorrhagic shock: gastrointestinal bleeding
• Hypovolemic shock: vomiting, diarrhea

2- Nephrotoxic insult:

Question 7

Acute Tubular Necrosis (Urinary, Lab & P.E findings)

Answer 7

Urinary findings

• Muddy brown granular casts
• Epithelial cells casts
• Free epithelial cells
• Proteinuria (mild)
• Microscopic hematuria (mild)
• No pyuria

** urine may be “normal” in less severe disease

Laboratory findings:

• Elevated serum Creatinine & BUN
• Metabolic acidosis ( low HC03 )
• Hyperkalemia
• Hyperphosphatemia
• Anemia (decrease erythropoietin)

Physical exam findings:

• Hypotension
• Low urine output (oliguria/anuria)
• Uremic signs (pericardial friction rub; confusion)

Question 8

Tubulointerstitial Nephritis