Immediate Management of Multiple Myeloma Patients Presenting with Tumor Lysis Syndrome
The immediate management of Multiple Myeloma (MM) patients presenting with Tumor Lysis Syndrome (TLS) requires aggressive hydration, rasburicase administration, electrolyte correction, and close monitoring, with consideration for dialysis in severe cases. 1
Initial Assessment and Interventions
Hydration and Urine Output
- Initiate aggressive IV hydration immediately to maintain urine output of at least 100 mL/hour in adults 2, 1
- Target hydration should begin 48 hours before chemotherapy when possible, but in emergency TLS situations, immediate hydration is critical 2
- Consider loop diuretics to maintain adequate urine output if needed, except in patients with obstructive uropathy or hypovolemia 1
Hyperuricemia Management
- Administer rasburicase at 0.20 mg/kg/day IV as first-line therapy for rapid uric acid degradation 1, 3
- Do not alkalinize urine when using rasburicase as it provides no additional benefit and may increase calcium phosphate precipitation 2
Electrolyte Management
Hyperkalemia
- For mild hyperkalemia (<6 mmol/L): hydration, loop diuretics, and sodium polystyrene 1 g/kg orally or as enema 1
- For severe hyperkalemia: insulin (0.1 units/kg) plus glucose (25% dextrose 2 mL/kg), calcium gluconate, and sodium bicarbonate with ECG monitoring 1
Hyperphosphatemia
- For mild hyperphosphatemia (<1.62 mmol/L): consider aluminum hydroxide 50-100 mg/kg/day divided in 4 doses 1
- For severe hyperphosphatemia: consider dialysis if unresponsive to medical management 1
Hypocalcemia
- Only treat symptomatic hypocalcemia (tetany, seizures) with calcium gluconate 50-100 mg/kg as a single dose 1
- Avoid routine calcium replacement in asymptomatic hypocalcemia as it may increase calcium phosphate precipitation 2
Monitoring Requirements
For the first 24 hours, monitor every 6 hours 2, 1:
- Vital parameters (heart rate, blood pressure, urine output, respiratory rate)
- Serum uric acid, electrolytes (phosphate, calcium, potassium)
- Renal function (serum creatinine, BUN)
- Urine pH and osmolality
Every 24 hours, assess 2:
- Blood cell count
- Serum LDH
- Albumin
- Serum osmolality
- Blood gases and acid-base equilibrium
- Electrocardiogram
- Body weight
Indications for Dialysis
Consider immediate dialysis for 1:
- Acute renal failure
- Severe electrolyte disturbances unresponsive to medical treatment
- Refractory volume overload
- Excessively elevated uric acid or phosphorus levels
- Severe metabolic acidosis
Special Considerations for Multiple Myeloma
- MM patients rarely develop TLS compared to other hematologic malignancies, but those with high tumor burden, high proliferative activity, elevated LDH, plasmablastic morphology, and unfavorable cytogenetics are at increased risk 4
- Pre-existing renal dysfunction, common in MM patients, increases TLS risk and complicates management 5
- Carfilzomib therapy has been associated with TLS in MM patients, requiring vigilance when using this agent 5
Pitfalls and Caveats
- Avoid urine alkalinization when using rasburicase as it provides no benefit and may worsen calcium phosphate precipitation 2
- Do not administer calcium to correct mild asymptomatic hypocalcemia as it increases risk of calcium phosphate tissue deposition 2
- Do not delay rasburicase administration in high-risk patients; it allows for earlier administration of chemotherapy if needed 2, 3
- Screen for G6PD deficiency before administering rasburicase to prevent hemolytic reactions 1
- Remember that MM patients with renal dysfunction may require dose adjustments of medications used in TLS management 5
By following this algorithm promptly, the potentially life-threatening complications of TLS in MM patients can be effectively managed, reducing morbidity and mortality.