ACUTE TUBULAR INJURY
Acute tubular injury (ATI) is acute renal failure associated with potentially revers-ible injury to the tubular epithelium. It is the most common cause of acute renal failure in the United States. It is characterized by oliguria with elevation of blood urea nitrogen (BUN) and creatinine; metabolic acidosis and hyperkalemia; and dirty brown granular casts and epithelial casts on urinalysis.
• Ischemic acute tubular necrosis is the most common cause of ATI. The condi-tion is due to decreased blood flow caused by severe hemorrhage, severe renal vasoconstriction, hypotension, dehydration, or shock.
• Nephrotoxic ATN has a large number of causes, including drugs (e.g., poly-myxin, methicillin, gentamicin, sulfonamides); radiographic contrast agents; heavy metals (e.g., mercury, lead, gold); organic solvents (e.g., carbon tetra-chloride, chloroform, methyl alcohol); ethylene glycol (antifreeze); mushroom poisoning; phenol; pesticides; and myoglobin.
The prognosis is excellent if the patient survives the underlying disease, and if the patient had no preexisting kidney disease.