Acute kidney injury Flashcards
What is an AKI
Reduction in renal function after an insult to the kidneys
5 RFs for AKI
- Chronic kidney disease
- other organ failure: heart failure, liver disease
- diabetes
- Drugs
- age 65 years or over
- use of iodinated contrast agents
- cognitive/ neurological impairment - may lead to oliguria
Name 5 drugs that are risk factor for AKI
- NSAIDs
- aminoglycosides
- ACE inhibitors
- angiotensin II receptor antagonists (ARBs)
- diuretics
Pre-renal causes of AKI
Reduced kidney perfusion due to:
* hypovolaemia secondary to diarrhoea/vomiting
* renal artery stenosis
* sepsis
Causes of intrinsic AKI
- glomerulonephritis
- acute tubular necrosis
- acute interstitial nephritis
- rhabdomyolysis
- haemolytic uraemic syndrome
Causes of post-renal AKI
obstruction of the urinary outflow tract due to:
* kidney stone in ureter or bladder
* benign prostatic hyperplasia
* tumours
* strictures
* urinary retention
Signs and symptoms of AKI
- Early AKI -> typically asymptomatic
- reduced urine output
- pulmonary and peripheral oedema
- arrhythmias (secondary to changes in potassium)
- features of uraemia (e.g. pericarditis or encephalopathy)
How are AKIs investigated
- Urea and electrolytes
- urinalysis
- renal ultrasound
According to the NICE guidelines, what are the criteria for diagnosing an AKI
Any of the following
* a rise in serum creatinine of ≥ 26 micromol/litre within 48 hours
* a 50% or greater rise in serum creatinine occurring in the past 7 days
* urine output < 0.5 ml/kg/hour over at least 6 hours
Give 3 drugs that may be stopped in AKI due to an increased risk of toxicity but don’t usually worsen AKI itself
- Metformin
- Lithium
- Digoxin
What NSAID is usually safe to continue in AKI
Aspirin (at a cardioprotective dose of 75mg od)
How is AKI managed
- IV fluids
- withhold meds that may exacerbate renal dysfunction
- specialist input from nephrologist where there’s severe AKI or doubt about the cause
- haemodialysis in severe cases
Indications for dialysis in the treatment of AKI
not responding to medical treatment of complications:
* hyperkalaemia
* pulmonary oedema
* acidosis
* uraemia (e.g. pericarditis, encephalopathy).
