What is the role of IV (intravenous) fluids in the management of Tumor Lysis Syndrome (TLS)?

Role of IV Fluids in Tumor Lysis Syndrome Management

Aggressive IV hydration is the cornerstone of both prevention and treatment of Tumor Lysis Syndrome (TLS), and should be initiated 48 hours before chemotherapy when possible, targeting a urine output of ≥100 mL/hour in adults or 3 mL/kg/hour in children. 1

Risk Stratification and Hydration Protocol

Hydration requirements should be determined based on TLS risk:

High-Risk Patients

• Volume: 2-3 L/m²/day (or 200 mL/kg/day if <10 kg) 2
• Solution: One-quarter normal saline/5% dextrose 2
• Target output: 80-100 mL/m²/hour (4-6 mL/kg/hour if <10 kg) 2
• Duration: Begin 48 hours before chemotherapy when possible 1
• Access: Central venous access recommended 1

Intermediate-Risk Patients

• Similar aggressive hydration as high-risk patients
• May consider allopurinol with hydration rather than rasburicase 2

Low-Risk Patients

• Hydration with oral allopurinol is generally sufficient 2

Monitoring During Hydration

• Urine output: Maintain within target range
• Urine-specific gravity: Maintain at 1.010 2
• Electrolytes: Monitor every 6 hours during first 24 hours 1
• Renal function: Monitor closely for signs of deterioration
• Body weight: Daily assessment 1

Important Considerations with IV Fluids

1. Electrolyte content: Initially withhold potassium, calcium, and phosphate from hydration fluids due to risks of hyperkalemia, hyperphosphatemia, and calcium phosphate precipitation 2

2. Diuretic use: If there is no evidence of acute obstructive uropathy or hypovolemia, loop diuretics (or mannitol) may be used to maintain target urine output 2, 1

3. Contraindications to aggressive hydration:

   • Renal failure
   • Oliguria
   • Pre-existing volume overload
   • Severe heart failure

4. Fluid balance: Attempt to achieve equal fluid intake and urinary output 2

Management of Refractory Cases

If volume overload becomes unresponsive to diuretic therapy despite adequate hydration, consider renal replacement therapy 2, 1, 3. Indications include:

• Persistent hyperkalemia
• Severe metabolic acidosis
• Volume overload unresponsive to diuretics
• Overt uremic symptoms (pericarditis, severe encephalopathy)
• Severe progressive hyperphosphatemia (>6 mg/dL)
• Severe symptomatic hypocalcemia 2

Hydration in Combination with Other Therapies

• With rasburicase: Aggressive hydration plus rasburicase is recommended for high-risk patients and those with clinical TLS 2, 1

• With allopurinol: Hydration plus oral allopurinol is recommended for low to intermediate-risk patients 2, 1

• Alkalinization: Currently not routinely recommended with hydration due to lack of evidence and potential risk of calcium phosphate precipitation 2. Only indicated for patients with metabolic acidosis 2

Pitfalls to Avoid

1. Inadequate hydration volume: Insufficient hydration is a common cause of treatment failure

2. Delayed initiation: Hydration should ideally begin 48 hours before chemotherapy in high-risk patients

3. Inappropriate fluid composition: Avoid fluids containing potassium, calcium, or phosphate initially

4. Overlooking fluid overload: Especially in patients with pre-existing cardiac or renal dysfunction

5. Relying solely on hydration: High-risk patients require combination therapy with hydration and rasburicase 2, 1

6. Delaying renal replacement therapy: Consider early initiation in patients with severe electrolyte disturbances or volume overload unresponsive to medical management 3

By following these guidelines for IV fluid administration in TLS, clinicians can significantly reduce morbidity and mortality associated with this oncologic emergency.