Acute Kidney Injury Flashcards
What is acute kidney injury?
Decrease in kidney function due to sudden damage, It can range from mild damage to kidney failure.
What are the 3 categories of AKI?
Pre-renal - caused by a reduction in perfusion
Renal - damage to kidney
Post-renal - obstruction
What are some of the causes of Pre Renal AKI?
VASCULAR - hypovolaemia (blood loss, fluid loss), kidney artery stenosis, emboli, heart failure, cardiac shock (tamponade)
INFECTION: septic shock (systemic vasodilation)
IATROGENIC - drugs NSAIDS (Pre glomerular vasocontriction)
What is seen in a urine analysis of a patient with a pre renal cause of AKI?
Urine normal however has hyaline casts - aggregations of protein seen in concentrated urine
What are some causes of renal AKI?
IATROGENIC - drugs - NSAIDs, ACE inhibitors, gentamicin, metformin
VASCULAR - vasculitis, thrombosis, severe acute ischaemia
AUTOIMMUNE- glomerulonephritis
INFECTION - interstital nephritis, acute pylonephritis
Acute Tubular Necrosis
What are some examples of nephrotoxins?
Damage the epithelial cells lining the tubules causing cell death and shedding into the lumen.
Endogenous - myoglobin, urate, bilirubin
Exogenous - X-ray contrast, ACEi, NSAIDs, gentamicin, aminoglycosides, weed killer, antifreeze
What are the causes of a post renal AKI?
Obstruction can occur at 3 sites
- Ureters (bilaterally)
- Entry into bladder
- Urethra
What are some common symptoms of renal calculi?
Haematuria and loin to groin pain (due to peristalsis of the ureters moving the calculi)
What is found in urinanalysis of a patient with glomerulonephritis?
Proteinuria, Haematuria and RBC casts
What is found in microscopy of urine from a patient with ATN?
Muddy brown casts
What would blood test results show in a patient with AKI?
Increased Urea and Creatinine
Which conditions can cause secondary glomerulonepritis?
SLE and vasculitis
involved as part of a systemic process
What is the treatment for a pre renal AKI?
Hypovolaemia –> fluid
heart failure –> diuretics
Correct underlying cause
What is the treatment for a post renal AKI?
Urological intervention to reestablish urine flow
What is the treatment for a ATN?
Maintaining good kidney perfusion and avoid nephrotoxins
What is an indication for dialysis?
When the kidneys can no longer excrete water, salts and potassium.
What are some complications of AKI?
Hyperkalaemia
Metabolic Acidosis
pulmonary oedema - caused by giving extra IV fluids to patients who are oliguric or anuric
What can be seen on an ECG in hyperkalaemia?
Tall tented T waves
Small/absent P waves
Increased PR interval
Wide QRS complex
