Tumour lysis syndrome

Definition

• Life-threatening syndrome of hyperuricemia and electrolyte abnormalities caused by sudden, massive cellular lysis that sometimes follows initiation of treatment for hematologic malignancies

Clinical Presentation

• Symptoms relate to underlying electrolyte abnormalities
• Nausea, vomiting, diarrhea, anorexia, lethargy, hematuria, heart failure, cardiac dysrhythmias, seizures, muscle cramps, tetany, syncope, and possible sudden death

Investigations

• Labs
  • Hyperkalemia ≥6 or 25% above baseline
  • Hyperphosphatemia ≥1.45 in adults (of ≥2.1 in children) or 25%
  • Hypocalcemia ≤1.75 or 25% below baseline
  • Hyperuricemia ≥476 or 25% above baseline
  • High LDH
  • Elevated creatinine

Classification (Cairo-Bishop)

Laboratory TLS

• Any two or more abnormal serum values:
  • Uric acid ≥476 umol/L or 25% above baseline
  • Potassium ≥6 mmol/L or 25% above baseline
  • Phosphorus ≥1.45 mmol/L or 25% above baseline
  • Calcium ≤1.75 mmol/L or 25% below baseline
• Present within 3 days before or 7 days after instituting chemotherapy
• In the setting of adequate hydration (with or without alkalinization) and use of a hypouricemic agent

Clinical TLS (CTLS)

• Laboratory TLS plus one or more of the following:
  • Increased serum creatinine concentration (≥1.5 times the upper limit of normal [ULN])
  • Cardiac arrhythmia/sudden death
  • Seizure

Management

Acute

• Allopurinol
• Rasburicase preferred in renal failure
• Lots of IV fluids
• Monitor potassium closely

Prevention

• Allopurinol preferred to rasburicase at a dose of 100 mg/m^2^ q8h
  • Dose-reduce for renal function