ATN, AIN, RTA

Question 1

ATN

Patho
Causes

Answer 1

Patho - cell death or detachment from basement membrane causing tubular dysfunction.

Causes

1. Ischaemia: hypo-perfusion by trauma, sepsis etc
2. exogenous toxins
   - aminoglycoside
   - amphotericin-B
   - NSAID
   - Contrast
   - Bacterial toxin
   - Chemo agents
3. Endogenous toxins
   - Uric acid
   - Myoglobin (Rhabdo) - acute pigment cast nephropathy

Question 2

ATN - Amioglycoside

CF

Answer 2

• after 5-7 days
• even if levels are “therapeutic”
• RF - longer duration of therapy, comorbidities, other causes that could precipitate AKI

Question 3

ATN - CF

Answer 3

• AKI
• Polyuria (distal tubules CANT concentrate urine)
• Muddy brown casts
• Hyaline cast

Question 4

AIN

Causes

Answer 4

RF - above 65 yoa

1. Meds
   - NSAIDs (most common)
   - Penicillin, cephalosporins
   - Rifampicin
   - Bactrim
   - Cipro
   - Duiretics
   - Mesalamine
   - PPI
2. Infections
   - Legionella, Lepto
   - CMV
   - Stre
   - MTB
   - E coli
3. Systemic disease
   - IgG4
   - Sjogrens
   - Sarcoid (most common autoimmune cause)
   - SLE

Question 5

AIN

- CF

Answer 5

-renal dysfunction + triad of rash, fever, eosinophillia (10%)

• oliguria
• eosinophilia + eosinophiluria
• fever
• rash
• hematuria or proteinuria

Urine - eosinophils, white cell casts, high Na

Question 6

Urine

AIN
ATN

Answer 6

AIN - WCC cast, eosinophiluria, high Na

ATN - muddy brown casts

Question 7

RTA Type 1

• location
• features
• causes
• CF

Answer 7

RTA 1 - Distal
-defect in hydrogen ion excretion

CF - severe hypoK, very low bicarb, renal stones/calcifications

a/w - medications, autoimune (Sjogren’s), HyperCa conditions etc

Mx - sodium bicarb

Question 8

RTA Type 2

• location
• features
• causes
• CF

Answer 8

RTA 2- Proximal
-reduced capacity to reclaim bicarb

-hypoK, acidic urine, low bicarb

a/w - Mutations, drugs, Fanconi syndrome, amyloidosis, MM, PNH etc

Question 9

Fanconi Syndrome

Answer 9

Generalized prox tubular dysfunction

CF

• Phophaturia
• Renal glucosuria
• Aminoaciduria
• Tubular proteinuria

Cause - genetics, Wilsons, ahminoglycosides etc

Question 10

RTA Type 4

• location
• features
• causes
• CF

Answer 10

Caused by reduced aldosterone production or aldosterone resistance

1. Reduced production
   - primary adrenal insufficiency
   - renal disease, NSAID, Calcineurin inhibitors etc
2. Resistance
   -drugs
   voltage defects

CF - low bicarb, hyPERK