renal failure, inability of the kidneys to excrete wastes, concentrate urine, and conserve electrolytes. The condition may be acute or chronic. See also acute tubular necrosis. ▪ OBSERVATIONS: Acute renal failure is characterized by oliguria and the rapid accumulation of nitrogenous wastes in the blood (azotemia). It results from hemorrhage, trauma, burn, toxic injury to the kidney, acute pyelonephritis or glomerulonephritis, or lower urinary tract obstruction. Many forms of acute renal failure are reversible after the underlying cause has been identified. Acute renal failure may have three typical phases: prodromal, oliguric, and postoliguric. Chronic renal failure may result from many other diseases. The early signs include sluggishness, fatigue, and mental dullness. Later, anuria, convulsions, GI bleeding, malnutrition, and various neuropathies may occur. The skin may turn yellow-brown. Congestive heart failure and hypertension are frequent complications, the results of hypervolemia. Urinalysis reveals greater-than-normal amounts of urea and creatinine, waxy casts, and a constant volume of urine regardless of variations in water intake. Anemia frequently occurs. ▪ INTERVENTIONS: Treatment includes restricted intake of fluids and of all substances that require excretion by the kidney. Antibiotics and diuretics are also used. ▪ PATIENT CARE CONSIDERATIONS: The prognosis depends on the underlying cause. When medical measures have been exhausted, long-term hemodialysis or peritoneal dialysis is often begun, and kidney transplantation is considered.
