Postoperative ATN: Differential diagnosis

Acute tubular necrosis (ATN) is the most common form of renal failure following surgery and is generally classified as either hypotensive (low cardiac output, low map, cross-clamp, cpb) OR nephrotoxic (inflammation [CPB], infection, atheroembolism, rhabdomyolysis, drugs [NSAIDs, aminoglycosides, cyclosporine, tacrolimus], toxins, or contrast-dye).

Note that, according to Miller, “Mechanical ventilation and positive end-expiratory pressure (PEEP) may cause decreased RBF, GFR, sodium excretion, and urine flow rate or even acute renal injury. Transmission of increased airway and intrapleural pressures to the intravascular space leads to decreases in venous return, transmural (i.e., effective) cardiac filling pressures, and cardiac output.”

Acute Tubular Necrosis

• Hypotensive: low cardiac output, low MAP, cross-clamp, mechanical ventilation
• Nephrotoxic: inflammation, infection, atheroembolism, rhabdomyolysis, drugs, toxins, or contrast dye
• Multifactorial: cardiopulmonary bypass