Tumor lysis syndrome: workup and management
Tumor lysis syndrome: hyperuricemia, hyperkalemia, hyperphosphatemia and secondary hypocalcemia from rapid tumor cell death, usually after starting therapy for high-grade lymphomas or acute leukemias. Prevention by risk group is key; established TLS needs aggressive hydration, rasburicase, electrolyte management and early nephrology input.
Working diagnosis
Adult · US guidelines
Draft · awaiting physician review
01Orient
What's new in the evidence
- BSH 2025: a single fixed 3 mg rasburicase dose for prophylaxis, repeated if needed; 0.2 mg/kg daily (often 3–5 days) for established TLS
- Observational target-trial data (BMJ 2026): rasburicase within 12 hours of TLS onset was associated with less need for dialysis or death
- Stop allopurinol while giving rasburicase
Differential diagnoses
- Laboratory tumor lysis syndrome
- Clinical TLS with AKI, arrhythmia or seizure (can't miss)
- AKI from contrast, nephrotoxins or sepsis
- Pseudohyperkalemia from very high WBC or platelets
02Assess
Risk scores and decision tools
- Cairo-Bishop laboratory and clinical TLS criteria
- Disease-based TLS risk (low, intermediate, high)
- G6PD status before rasburicase
Key history questions
- Malignancy type, tumor burden, timing of therapy
- Prophylaxis given (allopurinol, rasburicase, hydration)
- Urine output, muscle cramps, palpitations, seizures
- Preexisting kidney disease, nephrotoxic drugs
- G6PD status (before rasburicase)
Examination findings
- Volume status and urine output
- Tetany, Chvostek or Trousseau signs (hypocalcemia)
- Arrhythmia, edema
03Investigate
Initial investigations
- BMP, potassium, phosphate, calcium, uric acid, LDH every 6–12 hours in high-risk patients
- ECG
- Strict input and output
Advanced investigations
- G6PD before rasburicase
- Renal ultrasound to exclude obstruction
04Treat
Immediate management
- IV fluids to keep urine output about 80–100 mL/m²/h unless volume overloaded
- Treat hyperkalemia urgently (calcium for ECG changes, insulin–glucose, binders)
- Rasburicase 0.2 mg/kg IV (many centers use a single fixed dose) for high-risk or established TLS; contraindicated in G6PD deficiency
First-line treatment
- Prevention for intermediate risk: allopurinol plus hydration
- Phosphate binders for hyperphosphatemia
- Treat hypocalcemia only if symptomatic (calcium–phosphate precipitation risk)
- Avoid urinary alkalinization
Second-line treatment
- Dialysis for refractory hyperkalemia, volume overload, severe hyperphosphatemia or oliguric AKI
Specialist referrals
- Oncology/hematology
- Nephrology early
- ICU for clinical TLS
05Disposition
Admission criteria
- Laboratory or clinical TLS
- High-risk patients starting therapy
Safe discharge criteria
- Electrolytes stable and improving; renal function recovering
- Close lab follow-up arranged
Follow-up timing
- Labs daily to several times a week through the high-risk window
Patient instructions
- Keep drinking fluids; report reduced urine, cramps or palpitations
Monitoring
- Electrolytes every 6–12 hours initially
- Telemetry if hyperkalemia
Clinical pearls and pitfalls
- Draw uric acid samples on ice after rasburicase; it keeps working in the tube
- Rasburicase causes hemolysis and methemoglobinemia in G6PD deficiency
RefGuidelines and landmark evidence
- ReviewThe Tumor Lysis Syndrome (Howard, Jones & Pui, 2011)PubMed
- GuidelineGuidelines for the management of pediatric and adult tumor lysis syndrome (Coiffier et al., 2008)PubMed
- GuidelineBSH – Updated Guidelines for Tumour Lysis Syndrome (2025)PubMed
- TrialEarly rasburicase in adults with tumour lysis syndrome: emulated target trial (BMJ 2026)PubMed
For education only. Typical adult starting points; confirm doses against renal function, allergies, interactions and your institution's protocols. Not a substitute for clinical judgment or senior review.