MedEd Flashcards
what is AKI
rapid decline in renal function
what is CKD
impaired renal function for >3months
what are features of AKI
failure to maintain homeostasis of:
fluid - oliguria, volume overload
electrolytes - hyperkalaemia
acid-base - metabolic acidosis
what can causes of AKI be sorted into
pre-renal
renal
post-renal
what are causes of pre-renal AKI
failure of perfusion
- hypovolaemia (bleeding)
- reduced cardiac output (HF, LF, sepsis)
what are causes of renal AKI
drugs (ACEi, NSAIDs, aminoglyclosides) vascular glomerular tubular (ischaemia, rhabdomylosis) interstitial
what are post-renal causes of AKI
obstruction
- BPH
- kidney stones
- blocked catheter
- malignancy
what are vascular causes of AKI
large vessel (renal artery/vein obstruction, HTN, vasculitis) small vessel -HUS -TTP -DIC -vasculitis
what is HUS
triad of
1 microangiopathic haemolytic anaemia
2 AKI
3 thrombocytopenia
what is the main cause of HUS
gastroenteritis with e coli
what is the aetiopathophysiology of HUS
gastroenteritis (ecoli) releases toxins which cause endothelial damage, this leads to thrombosis, platelet consumption and fibrin strand deposition
RBCs get cut up by fibrin strands and under go haemolysis
what are features of HUS on presentation
abdo pain and dysentry
AKI (N+V, oliguria, haematuria, proteinuria)
bleeding due to thrombocytopenia
fatigue due to MAHA
what is the aetiopathophysiology of TTP
deficiency of protein which cleaves vWF
large vWF multimers form
platelet aggregation and fibrin deposition occurs which can cause microthrombi in the kidneys
what is TTP
1 microangiopathic haemolytic anaemia
2 AKI
3 thrombocytopenia
4 fluctuating CNS signs
1. A young woman presents after a seizure. She is noted to have a fever and icterus. Her urine output is low. The most likely diagnosis is: A) Haemolytic Uraemic Syndrome B) Renal stone C) Thrombotic Thrombocytopenic Purpura D) Hepatic failure E) Polycystic kidney disease
TTP
what are consequences of glomerulonephritis
loss of barrier function
loss of filtering capacity
what are features of loss of barrier function
- proteinuria
- haematuria
what are features of loss of filtering capacity
-reduced excretion which causes accumulation of waste products
what are causes of glomerulonephritis
1 IgA nephropathy 2 Henoch Schonlein Purpura 3 Anti-GBM (goodpastures) 4 post-strep glomerulonephritis 5 pauci-immune
what features are present with IgA nephropathy
days following URTI
increased IgA immune complex formation
episodic haematuria
what features are present with HSP
systemic variant IgA nephropathy
haematuria
purpuric rash on extensor surfaces commonly in legs
polyarthritis
what features are present with anti-GBM (goodpastures)
autoantibodies to Type IV collagen (GBM & lung)
haematuria
haemoptysis
what features are present with post-strep glomerulonephritis
post strep or skin infection
strep antigens are deposited at the glomerulus which leads to immune complex formation
nephritic syndrome
what features are present with pauci immune
ANCA
associated vasculitis or limited to kidney