Acute Tubular Necrosis

ATN: What is it?

• Most common intrinsic (renal) cause of AKI

• Due to renal tubular epithelial cell damage

• This may be due to nephrotoxic drugs or ischaemia

ATN: What are the risk factors?

• Hypovolaemia

• Old age

• CKD

• Nephrotoxic drugs

ATN: What are some examples of nephrotoxic medications?

• Aminoglycoside antibiotics (e.g. gentamicin)

• Antifungals (e.g. amphotericin)

• Chemotherapy agents (e.g. cisplatin)

• Antivirals (e.g. tenofovir)

• Nonsteroidal anti-inflammatory drugs (NSAIDs)

• Contrast agents

• Myoglobin (rhabdomyolysis)

ATN: What are the symptoms?

• Lethargy and malaise

• Nausea and vomiting

• Oliguria or anuria (polyuria may be seen in the recovery phase)

• Confusion

• Drowsiness

• Peripheral oedema

ATN: What are the bedside investigations?

• Urine microscopy→ muddy brown granular cases

• Urinary sodium is high (>40)

• Urine osmolality is low (<450)

• VBG for acidosis and hyperkalaemia

ATN: What are the bloods investigations?

• U&Es

• Urea:creatinine ratio is low

• FBC

• Creatine kinase to rule out rhabdomyolysis

• LFT CRP

• Blood cultures

• Coagulation screen

ATN: What is the management?

• Stop nephrotoxic drugs

• Catheter if needed

• Treat underlying cause

• IV fluids for hypovolaemia ± hypotension

• Blood products if due to haemorrhage

• If severe, dialysis may be indicated