Which of the following statement(s) is/are true concerning various causes of acute renal failure?

a. Acute tubular necrosis is the most common pathologic finding of acute renal failure

b. Drug-induced renal failure is compounded in situations of hypovolemia

c. Myoglobin-induced renal failure can be prevented using diuretics and alkalization of urine

Acute tubular necrosis results from ischemia to the renal parenchyma and is the most common pathologic finding of acute renal failure. In conditions of diminishing renal blood flow, perfusion to the kidneys is first maintained by vasomotor responses which dilate the afferent arteriole and constrict the efferent arteriole. As continued hypotension occurs, the reninangiotensin system is activated and vasoconstriction of the afferent arteriole occurs which exacerbates corticohypoperfusion. Pigment nephropathy is a common cause of acute renal failure occurring after trauma, burns, operations, or hemodynamic catastrophe. With ischemia or blunt injury to large muscles, myoglobin is released into the circulation. In the kidney, it is filtered from blood and reabsorbed by the tubule. Although myoglobin is not a direct nephrotoxin, in the presence of aciduria, myoglobin is converted to ferrihemate, which is toxic to renal cells. Prevention of myoglobin-induced renal failure may include the use of diuretics and alkalinization of urine. Drug-induced acute renal failure is responsible for approximately 5% of all cases of acute renal failure. Through normal reabsorption and secretion, the kidney is exposed to high concentrations of drugs and solutes, which may be toxic. This problem is compounded by hypovolemia, which causes increased reabsorption of water and solutes and exposes the lumen to even higher concentrations of toxins. The incidence of radiographic contrast dye induced nephropathy is approximately 1 to 10% and may be predicted according to a number of risk factors which include contrast load, age, preexisting renal insufficiency, and diabetes. The incidence in patients with normal renal function is significantly lower at 1% to 2%.