Acute Kidney Injury (AKI) Flashcards
define AKI
abrupt (less than 48 hour) reduction in kidney function due to tubular cell death
criteria for AKI
increase in serum creatinine >26.4umol/L
OR increase in creatinine by 50%
OR reduction in UO
risk factors for AKI
older CKD diabetes cardiac failure liver disease PVD previous AKI
exposure risk factors
hypotension hypovolaemia sepsis recent contrast certain medication
classification
- pre-renal
- renal
- post-renal
causes of pre-renal
hypovolaemia (dehydration, haemorrhage)
hypotension (cardiogenic shock, distributive shock- sepsis, anaphylaxis)
infection (schistosomiasis)
renal hypoperfusion (NSAIDs, COX2, ACEI/ARB and hepatorenal syndrome)
what does untreated pre-renal AKI lead to?
acute tubular necrosis
tubular necrosis presentation?
muddy brown casts of epithelial cells
role of ACEI on the kidney
vasodilation of efferent arteriole which blocks vasoconstriction by angiotensin II
diagnosis of pre-renal AKI
assess for hydration (BP, HR, JVP, cap refill, oedema)
fluid challenge for hypovolaemia (crystalloid or colloid, do NOT use dextrose)
when to get help in fluid challenge?
> 1000mls and no improvement
define renal AKI
inflammation or damage to renal cells
causes of renal AKI
- vascular= vasculitis
- glomerular= GN
- interstital nephritis= drugs, infection (TB) and systemic (sarcoid)
- tubular injury= ischaemia, drugs (gentamicin), contrast and rhabdomyolysis
define post-renal AKI
obstruction, usually leads to hydronephrosis (usually only affects one kidney)
causes of post-renal AKI
stones
cancer
strictures
external pressures
management of post-renal AKI
relieve obstruction (catheter, nephrostomy)
drugs that cause AKI (DAMN)
diuretics
ACEI/ARB
metformin
NSAIDs
sick day rules= stop if vomiting, diarrhoea or infection
presentation of AKI
non-specific= weight loss, fatigue, lethargy
vomiting
breathless (metabolic acidosis or pulmonary oedema)
fluid overload
uraemia (itch, pericarditis)
oliguria
diagnosis of AKI
U&Es FBC and clotting BP urinarylsis USS obstruction immunology (ANA, ANCA, GBM) protein electrophoresis and BJP
management of AKI
good perfusion= fluid resuscitate (inotropes, vasopressors)
antibiotics if sepsis
dialysis if anuria and uraemia
stop nephrotoxics
life-threatening complications of AKI
hyperkalaemia
fluid overload
severe acidosis (pH <7.15)
uraemic pericardial effusion/ severe uraemia
what is hyperkalaemia associated with?
cardiac arrhythmias
how to diagnosis hyperkalaemia?
ECG
muscle weakness
management of hyperkalaemia
- protect myocardium with calcium gluconate
- insulin and salbutamol (move K+ back into cells)
- calcium resonium (NOT in acute setting- GI tract)
urgent indications for dialysis
hyperkalaemia (>7)
severe acidosis (pH <7.15)
fluid overload
urea >40 (pericardial effusion/ itch)
consider symptoms and their effects
