Acute Tubular Necrosis Flashcards
What is acute tubular necrosis?
Damage and necrosis of epithelial cells of renal tubules. Damage to kidney cells occurs due to ischaemia or toxins.
What is the most common cause of AKI?
Acute tubular necrosis
Discuss whether acute tubular necrosis is reversible
Epithelial cells have ability to regenerate so ATN is reversible; takes about 7-21 days
We have said ATN can occur due to ischaemia or toxins; state some ischaemic causes and state some toxin causes
Ischaemia can occur secondary to hypoperfusion in:
- Shock
- Sepsis
- Dehydration
Direct damage from toxins such as:
- Radiology contrast dye
- Gentamycin
- NSAIDs
What investigation finding is pathognomonic for acute tubular necrosis?
Muddy brown casts on urinalysis
May also be tubular epithelial cells in urine
Discuss the mangement of ATN
REMEMBER, ATN is most common cause of AKI hence most of our management is same as for AKI:
- Supportive management
- IV fluids
- Stop nephrotoxic medications
- Treat complications
Define interstitial nephritis
Inflammation of space between cells and tubules (interstitium) within kidney. Different to glomerulonephritis in which there is inflammation around the glomerulus.
State the two types of interstitial nephritis
- Acute interstitial nephritis
- Chronic interstitial nephritis
For acute interstitial nephritis, discuss:
- How it presents
- Causes
- Management
- Presents with AKI and hypertension. May also present with feaatures of generalised hypersensitivity e.g. rash, fever, eosinophilia
- Usually caused by hypersensitivity reaction e.g. to drugs (NSAIDs, abx e.g. beta lactams) or infection
- Management:
- Treat underlying cause/withdraw causative agent
- Steroids to reduce inflammation
For chronic interstitial nephritis, discuss:
- How it presents
- Causes
- Management
- Presents with CKD
- Causes: autoimmune, infectious, iatrogenic, granulomatous disease
- Management:
- Treat underlying cuase
- Steroids (specialist involvement)
What is rhabdomyolysis?
State some possible causes
Skeletal muscle tissue breaks down and releases products into blood.
Triggerd by event that causes muscle breakdwon e.g. extreme underuse or overuse, crush injury, seizure, prologned immobility etc…
When mycotyes undergo apoptosis in rhabdomyolysis, what 4 things are released into blood
- Myoglobin
- Potassium
- Phosphate
- Creatine kinase
Of the products released by myocytes when they undergo apoptosis, which is most dangerous and why?
- Potassium
- Cardiac arrhythmias which can result in cardiac arrest
Discuss the impact of rhabdomyolysis on kidneys
- Breakdown products are filtered by kidney
- Myoglobin is toxic to kidney in high concentrations and can cause AKI
- AKI cuases breakdown products to further accumulate in blood
State some signs & symptoms of rhabdomyolysis
- Muscle aches & pains
- Oedema
- Fatigue
- Confusion
- Red-brown urine