What is the treatment for tumor lysis syndrome?

Treatment of Tumor Lysis Syndrome

Immediately initiate aggressive intravenous hydration plus rasburicase 0.2 mg/kg IV over 30 minutes for all patients with clinical tumor lysis syndrome to prevent life-threatening complications including acute renal failure, cardiac arrhythmias, seizures, and death. 1, 2

Core Treatment Strategy

Immediate Interventions

• Start IV hydration through central venous access at least 48 hours before chemotherapy when possible, maintaining urine output at minimum 100 mL/hour (or 3 mL/kg/hour in children <10 kg) 2
• Administer rasburicase 0.2 mg/kg IV over 30 minutes immediately, continuing for 3-5 days as needed, with the first dose given at least 4 hours before chemotherapy when possible 2, 3
• Add loop diuretics (furosemide 40-80 mg IV) or mannitol to achieve target urine output if needed, except in patients with obstructive uropathy, hypovolemia, anuria, or established oliguria 2, 1
• Do NOT give allopurinol concurrently with rasburicase, as this causes xanthine accumulation and removes substrate for rasburicase 2

The FDA label demonstrates that rasburicase reduces plasma uric acid to ≤2 mg/dL in 96% of patients within 4 hours of the first dose, with 87% of patients achieving uric acid response rates compared to 66% with allopurinol alone 3. This rapid action is critical for preventing complete renal shutdown.

Management of Hyperkalemia

Mild Hyperkalemia (<6 mmol/L)

• Initiate aggressive IV hydration plus loop diuretics (furosemide 40-80 mg IV) to enhance renal potassium excretion 1, 2
• Consider sodium polystyrene 1 g/kg orally or by enema for additional potassium removal 1

Severe Hyperkalemia (≥6 mmol/L or ECG Changes)

• Administer calcium gluconate 50-100 mg/kg IV over 2-5 minutes to stabilize myocardial membrane (effects begin within 1-3 minutes but last only 30-60 minutes; does not lower serum potassium) 1, 2, 4
• Give rapid insulin 0.1 units/kg IV plus 25% dextrose 2 mL/kg IV for maximum effect (onset 15-30 minutes, duration 4-6 hours) 1, 2, 4
• Obtain immediate ECG looking for peaked T waves, flattened P waves, prolonged PR interval, and widened QRS complex, which indicate urgent treatment regardless of absolute potassium level 4
• Initiate continuous ECG monitoring to detect hyperkalemia-induced arrhythmias 2, 4

Management of Hypocalcemia

• Do NOT treat asymptomatic hypocalcemia, as calcium administration can precipitate calcium-phosphate crystals in tissues and worsen renal injury 1
• Treat symptomatic hypocalcemia manifesting as tetany or seizures with calcium gluconate 50-100 mg/kg IV infused cautiously and repeated if necessary 1

This is a critical pitfall to avoid: treating asymptomatic hypocalcemia can paradoxically worsen renal function through tissue precipitation.

Management of Hyperphosphatemia

• Mild hyperphosphatemia (<1.62 mmol/L) does not require treatment 1
• For severe elevations (>1.62 mmol/L), use aluminum hydroxide 50-100 mg/kg/day divided in 4 doses as phosphate binders 2, 4

Indications for Urgent Hemodialysis

Initiate hemodialysis immediately when any of the following occur: 1, 2

• Oliguria or anuria develops despite aggressive hydration
• Severe refractory hyperkalemia (≥6 mmol/L unresponsive to medical management)
• Symptomatic hypocalcemia refractory to treatment
• Severe hyperphosphatemia with calcium-phosphate precipitation
• Volume overload unresponsive to diuretic therapy

Hemodialysis is the most effective and reliable method for removing potassium from the body in refractory cases 4.

Laboratory Monitoring Protocol

• Recheck potassium every 2-4 hours after initial treatment 1, 2
• Monitor uric acid, electrolytes, phosphate, and calcium every 6 hours for the first 24 hours 1, 2
• Measure hourly urine output to ensure adequate renal perfusion 2
• Obtain comprehensive metabolic panel, LDH, and CBC immediately when TLS is suspected 1, 2

Critical Sample Handling

Follow special sample handling procedures for uric acid measurements: rasburicase causes enzymatic degradation of uric acid in blood/plasma/serum samples at room temperature, potentially resulting in spuriously low readings 3. This can lead to underestimation of disease severity.

Treatment for Laboratory TLS

• Treat all adults with laboratory TLS (≥2 metabolic abnormalities: hyperuricemia, hyperkalemia, hyperphosphatemia, hypocalcemia) the same as clinical TLS with aggressive hydration and rasburicase 2
• Treat children at high risk for TLS the same as clinical TLS even if only laboratory criteria are met 2