Tubular Diseases

Question 1

What is acute tubular necrosis

Answer 1

Damage to the tubular epithelial cells within the renal tubules

Question 2

Features of acute tubular necrosis

Answer 2

AKI with oliguria, uraemia and electrolyte imbalance

Question 3

Ischamic causes of acute tubular necrosis

Answer 3

Hypotension, shock (haemorrhagic, cardiogenic, septic), direct vascular injury (trauma, surgery)

Question 4

Nephrotoxic causes of acute tubular necrosis

Answer 4

Drugs such as aminoglycosides, antifungals, chemotherapy agents, NSAIDs, ACEIs, ARBs, statins and contrast

Question 5

What does urinalysis in acute tubular necrosis show

Answer 5

Brown casts from renal tubular cells which have been broken away

Question 6

Management of acute tubular nectosis

Answer 6

Treat underlying cause, supportive therapy, removal of nephrotoxins, may require haemofiltration or haemodialysis

Question 7

What is ATN the most common cause of

Answer 7

Intrinsic AKI

Question 8

What happens in renal tubular acidosis

Answer 8

Impaired acid excretion leads to hyperchloraemic metabolic acidosis, which leads to activation of RAS causing K+ wasting and hypokalaemia

Question 9

What is the type 1 cause of renal tubular acidosis

Answer 9

Pathology in distal tubule so inability to excrete H+ ions.

Question 10

Diseases which cause type 1 renal tubular acidosis

Answer 10

Marfan’s, Ehlers-Danlos, Sjogren’s, SLE, thyroiditis, drugs

Question 11

Symptoms of type 1 renal tubular acidosis

Answer 11

Rickets, osteomalacia, renal stones, UTI, CKD

Question 12

Diagnosis of type 1 renal tubular acidosis

Answer 12

Failure to acidify urine (ph >5.5) despite acid load

Question 13

Treatment of renal tubular acidosis

Answer 13

Sodium bicarbonate and correct other electrolye imbalances

Question 14

What is type 2 cause of renal tubular acidosis

Answer 14

Pathology in proximal tubule, inabiluty to reabsorb HCO3 ions

Question 15

Diseases which can cause type 2 renal tubular acidosis

Answer 15

Faconi syndrome, and acquired damage from drugs

Question 16

Symptoms of type 2 renal tubular acidosis

Answer 16

Polyuria, hypophosphataemia, rickets (VIt D resistant), acidosis, low K+.

Question 17

Diagnosis of type 2 renal tubular acidosis

Answer 17

Urine will acidify with acid load

Question 18

Treatment of type 2 renal tubular acidosis

Answer 18

Oral sodium bicarbonate and treat other electrolyte imbalances

Question 19

What is type 3 renal tubular acidosis

Answer 19

Combination of type 1 and type 2

Question 20

What is type 4 renal tubular acidosis

Answer 20

Reduced aldosterone responsible for Na+ reabsorption and H+/K+ excretion. No ammonia is produced as Na+ reabsorption stimulates release leading to acidic urinary pH

Question 21

Symptoms of type 4 renal tubular acidosis

Answer 21

Acidic urinary pH, high chloride levels and hyperkalaemia

Question 22

Treatment of type 4 renal tubular acidosis

Answer 22

Treat with fludrocortisone and treat hyperkalaemia

Question 23

What is tubular interstitial nephritis

Answer 23

Immune/hypersensitivity reaction against tubular epithelium

Question 24

Symptoms of tubular interstitial nephritis

Answer 24

Acute renal failure, fever, arthralgia, eoisinophilia and rash. Can be 2-40 days after

Question 25

Drug causes of tubular interstitial nephritis

Answer 25

Antibiotics (penicillin, cephalosporins and quinolones), NSAIDs, diuretics, rifampicin, allopurinol, PPIs

Question 26

Immune causes of tubular interstitial nephritis

Answer 26

Idiopathic tubulointerstitial nephritis, TIN with uveitis, TIN associated with SLE, Sjogren syndrome and IgG4-related, sarcoidosis

Question 27

Treatment of tubular interstitial nephritis

Answer 27

Removal of agent, steroid immunotherapy unless presentation too late