Acute kidney injury diseases

Question 1

Pre-renal AKI

Answer 1

Reduced renal blood flow –> GFR down
changes circulating volume (hypovolaemia)
intrarenal vasomotor changes that drop glomerular perfusion pressure
kidney retains fluid to improve blood flow + Na retention

Question 2

Post-renal AKI

Answer 2

obstruction urinary tract, backpressure

bladder outflow or ureters

Question 3

Intrarenal AKI (parenchymal)

Answer 3

injury to glomerulus, tubules or interstitium
Acute tubular necrosis
Acute tubulointerstitial nephritis

Question 4

Drug-induced acute TIN

Answer 4

asymptomatic or fever, arthralgia, skin rashes, acute oliguria, eosinophilia

Question 5

Infection causing TIN + hantavirus why special?

Answer 5

pyelonephritis (bacterial) –> inflammation tubules with neutrophilic cellular infiltrate
Hantavirus causes haemorrhagic fever –> fatal

Question 6

Acute TIN as part of multisystem inflammatory disease

Answer 6

Sjögren, SLE, granulomatosis
Sarcoidosis presents in 20% of cases als granulomatosis with TIN
hypercalcaemia

Question 7

TIN with uveitis syndrome

Answer 7

uveitis, acute TIN, weight loss, anaemia, raised ESR

childhood, adult women

Question 8

Chronic TIN

Answer 8

polyuria, nocturia, proteinuria, uraemia, papillary necrosis
sloughed papilla can cause ureteric colic or obstruction

Question 9

Hyperuraecemic nephropathy

Answer 9

part tumour lysis syndrome –> AKI in patients with high serum urate often after treatment
obstruction due to uric acid crystals

Question 10

Acute tubular necrosis (ATN): patho

Answer 10

Ischaemia –> proximal straight + thick ascending limb
Nephrotoxins –> proximal convoluted & straight
Vasoconstriction
reversible disease
intratubular pressure up due to obliteration –> GFR down

Question 11

ATN clinical features

Answer 11

uraemia, anorexia, nausea, vomiting, pruritis, epistaxis, interstitial oedema
hyperkalaemia, metabolic acidosis, hyponatraemia, pulmonary oedema

Question 12

How can NSAIDs cause nephropathy?

Answer 12

NSAIDs inhibit cyclo-oxygenase enzyme –> needed in prostaglandin synthesis –> prostaglandin normally causes vasodilation, not anymore leading to ischaemia

Question 13

4 Pathologic response of glomerulus to injury?

Answer 13

Hypercellularity –> crescent formation
Basement membrane thickening
Hyalinosis –> eosinophils
Sclerosis –> collagenous