USMLE Prep - Medical Reference Library

Tumor Lysis Syndrome — Prevention & Management

System: Hematology Oncology • Reviewed: Aug 31, 2025 • Step 1Step 2Step 3

Synopsis:

Oncologic emergency from rapid cell lysis causing hyperuricemia, hyperkalemia, hyperphosphatemia, and hypocalcemia. Prevent with risk stratification, vigorous hydration, and urate‑lowering therapy; manage electrolyte derangements promptly; dialyze if refractory.

Key Points

  • Stabilize ABCs; begin targeted evaluation without delaying life-saving therapy.
  • Use system-specific risk tools to guide testing and disposition.
  • Order high-yield tests first; escalate imaging when indicated.
  • Start evidence-based initial therapy and reassess frequently.

Algorithm

  1. Primary survey and vitals; IV access and monitors.
  2. Focused history/physical; identify red flags and likely etiologies.
  3. Order system-appropriate labs and imaging (see Investigations).
  4. Initiate guideline-based empiric therapy (see Pharmacology).
  5. Reassess response; arrange consultation and definitive management.

Clinical Synopsis & Reasoning

For Tumor Lysis Syndrome Prevention Management, frame the differential by acuity and pathophysiology, then align diagnostics to the leading hypotheses. Prioritize stabilization while obtaining high‑yield studies such as CBC with diff (Cytopenias/leukocytosis), Coags (Bleeding/clotting), Smear (Morphology). Incorporate bedside imaging and targeted labs to define severity and identify complications; synthesize results with clinical trajectory to refine the working diagnosis and disposition needs.


Treatment Strategy & Disposition

Initiate disease‑directed therapy alongside supportive care, titrating to objective response. Pharmacologic options commonly include Anti-pseudomonal β-lactam. Use validated frameworks (e.g., TLS Risk & Prevention) to guide escalation and site of care. Address precipitating factors, de‑escalate empiric therapies with data, and arrange follow‑up for monitoring and risk‑factor modification; admit patients with instability, high risk of deterioration, or needs for close monitoring.


Management Notes

Avoid xanthine nephropathy with allopurinol by ensuring hydration. Rasburicase contraindicated in G6PD deficiency.


Epidemiology / Risk Factors

  • Cytotoxic chemotherapy, neutropenia; lines

Investigations

TestRole / RationaleTypical FindingsNotes
CBC with diffCytopenias/leukocytosisAbnormal counts
CoagsBleeding/clottingAbnormalities
SmearMorphologyAbnormal cells

TLS Risk & Prevention

RiskApproach
LowHydration ± allopurinol
IntermediateHydration + allopurinol; consider rasburicase if rising uric acid
High/establishedHydration + rasburicase; ICU‑level monitoring
MonitoringLabs q6–12 h; strict I/O
DialysisFor refractory electrolyte/renal failure

Pharmacology

MedicationMechanismOnsetRole in TherapyLimitations
Aggressive IV fluidsVolume expansionHoursPrevent AKIFluid overload
Rasburicase (selected)Uric acid oxidationHoursHigh-risk or established TLSG6PD contraindication
Allopurinol (prophylaxis)Xanthine oxidase inhibitionDaysPrevention before chemoRash

Prognosis / Complications

  • Tied to depth/duration of neutropenia and comorbidities

Patient Education / Counseling

  • Explain red flags and when to seek emergent care.
  • Reinforce medication adherence and follow-up plan.

References

  1. ASCO/ASH TLS Guidance — Link