Tumor lysis syndrome in the emergency department: challenges and solutions.

Tumor lysis syndrome (TLS) is the most common oncologic emergency. It is caused by rapid tumor cell destruction and the resulting nucleic acid degradation during or days after initiation of cytotoxic therapy. Also, a spontaneous form exists. The metabolic abnormalities associated with this syndrome include hyperkalemia, hyperphosphatemia, hypocalcemia, hyperuricemia, and acute kidney injury. These abnormalities can lead to life-threatening complications, such as heart rhythm abnormalities and neurologic manifestations. The emergency management of overt TLS involves proper fluid resuscitation with crystalloids in order to improve the intravascular volume and the urinary output and to increase the renal excretion of potassium, phosphorus, and uric acid. With this therapeutic strategy, prevention of calcium phosphate and uric acid crystal deposition within renal tubules is achieved. Other measures in the management of overt TLS are prescription of hypouricemic agents, renal replacement therapy, and correction of electrolyte imbalances. Hyperkalemia should be treated quickly and aggressively as its presence is the most hazardous acute complication that can cause sudden death from cardiac arrhythmias. Treatment of hypocalcemia is reserved for patients with electrocardiographic changes or symptoms of neuromuscular irritability. In patients who are refractory to medical management of electrolyte abnormalities or with severe cardiac and neurologic manifestations, early dialysis is recommended.