Interstital Nephritides and Nephrotoxins Flashcards

1
Q

What is Acute Interstitial / Tubulointerstitial Nephritis

A

Immune-mediated hypersensitivity ̄c either drugs or other Ag acting as haptans

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2
Q

Causes of Acute Interstitial / Tubulointerstitial Nephritis

A
Drug hypersensitivity in 70%
  NSAIDs
  Abx: Cephs, penicillins, rifampicin, sulphonamide   Diuretics: frusemide, thiazides
  Allopurinol
  Cimetidine

Infections in 15%
Staphs, streps

Immune disorders
SLE, Sjogren’s

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3
Q

Presentation of interstitial nephritides

A

Fever, arthralgia, rashes
AKI → olig/anuria
Uveitis

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4
Q

Investigations

A

↑IgE, eosinophilia

Dip: haematuria, proteinuria, sterile pyuria

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5
Q

Treatment

A

Stop offending drug

Prednisolone

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6
Q

Chronic TIN

A

Fibrosis and tubular loss
Commonly caused by:
Reflux and chronic pyelonephritis DM
SCD or trait

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7
Q

What is Analgesic nephropathy

A

Prolonged heavy ingestion of compound analgesics

Often a Hx of chronic pain: headaches, muscle pain

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8
Q

Features of analgesic nephropathy

A

Sterile pyuria ± mild proteinuria
Slowly progressive CRF
Sloughed papilla can → obstruction and renal colic

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9
Q

Investigations and treatment of chronic TIN

A

Ix: CT w/o contrast (papillary calcifications) Rx: stop analgesics

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10
Q

Acute rate crystal nephropathy - cause and treatment

A

AKI due to urate precipitation
Usually after chemo-induced cell lysis
Rx: hydration, urinary alkalinisation

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11
Q

What is Nephrocalcinosis and its causes

A
Diffuse renal parenchymal calcification
  Progressive renal impairment
  Causes
  Malignancy
  ↑PTH
  Myeloma
  Sarcoidosis
  Vit D intoxification   RTA
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12
Q

What do nephrotoxins do

A

Either directly toxic → ATN

Or cause hypersensitivity → TIN

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13
Q

Exogenous nephrotoxins

A
NSAIDs
  Antimicrobials: AVASTA
  Aminoglycosides   Vancomycin
  Aciclovir
  Sulphonamides   Tetracycline
  Amphotericin   ACEi
  Immunosuppressants   Ciclosporin
  Tacrolimus   Contrast media
  Anaesthetics: enflurane
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14
Q

Endogenous nephrotoxins

A

Haemoglobin, myoglobin
Urate
Ig: e.g. light chains in myeloma

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15
Q

Pathogenesis of Rhabdomyolysis

A

Skeletal muscle breakdown → release of: K+, PO4, urate
Myoglobin, CK
↑K and AKI

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16
Q

Causes of Rhabdomyolysis

A

Ischaemia: embolism, surgery
Trauma: immobilisation, crush, burns, seizures,
compartment syndrome
Toxins: statins, fibrates, ecstasy, neuroleptics

17
Q

Clinical features

A

Muscle pain, swelling
Red/brown urine
AKI occurs 10-12h later

18
Q

Investigations of Rhabdomyolysis

A

Dipstick: +ve Hb, -ve RBCs

Blood: ↑CK, ↑K, ↑PO4, ↑urate

19
Q

Treatment of rhabdomyolysis

A
Rx hyperkalaemia
  IV rehydration: 300ml/h
  CVP monitoring if oliguric
  IV NaHCO3 may be used to alkalinize urine and stabilise
a less toxic form of myoglobin.