Metabolic emergencies in oncology

Abstract

Tumor lysis syndrome (TLS) refers to the constellation of electrolyte abnormalities that occur as a result of the rapid and immediate release of intracellular contents into the bloodstream. The syndrome is characterized by hyperuricemia, hyperkalemia, hyperphosphatemia, and hypocalcemia (Table 72.1). Metabolic acidosis and acute renal failure may also occur. The release of intracellular potassium and organic, as well as inorganic, phosphate into the bloodstream from cells undergoing apoptosis, results in the development of hyperkalemia and hyperphosphatemia, respectively. Prolonged and severe hyperphosphatemia may result in a marked decrease of the serum calcium concentration, but symptomatic hypocalcemia rarely develops. It is the rapid breakdown of nucleic acids that leads to hyperuricemia. TLS may develop before the administration of chemotherapy in patients with rapidly proliferating hematologic neoplasms; however, TLS usually occurs after the administration of high doses of chemotherapy, which results in the rapid destruction of tumor cells. © 2006 Springer Science+Business Media, Inc.