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Tumor Lysis Syndrome (TLS)

Diagnosis · Risk Stratification · Surveillance · Management
No Thai national CPG exists for TLS. This reference follows the British Society for Haematology (BSH) 2025 update and Cairo-Bishop criteria (2004), consistent with NCCN. Verify against Songklanagarind / PSU institutional protocol before clinical use.

① Diagnostic Criteria — Cairo-Bishop

Laboratory TLS

≥2 of the following, occurring within the same 24h period, from 3 days before to 7 days after cytotoxic therapy:
AnalyteThreshold
Uric acid≥8.0 mg/dL (476 µmol/L) or 25% ↑ from baseline
Potassium≥6.0 mEq/L or 25% ↑ from baseline
Phosphate≥4.5 mg/dL adult / ≥6.5 mg/dL child (≥1.45 mmol/L) or 25% ↑ from baseline
Calcium (corrected)≤7.0 mg/dL (1.75 mmol/L) or 25% ↓ from baseline

Clinical TLS

Laboratory TLS plus ≥1 of:

Clinical TLS Grading

GradeCreatinineArrhythmiaSeizure
0≤1.5× ULNnonenone
11.5× ULNintervention not indicated—
2>1.5–3.0× ULNnon-urgent intervention indicated1 brief generalized seizure, controlled
3>3.0–6.0× ULNsymptomatic, incompletely controlled medicallyseizures poorly controlled
4>6.0× ULNlife-threateningprolonged/repetitive, status epilepticus
Source: Cairo MS, Bishop M. Br J Haematol 2004;127(1):3–11.

② Risk Stratification

RiskTypical malignancy / setting
LowMost solid tumors; indolent NHL/CLL without bulky disease; low WBC ALL/AML
IntermediateBulky/advanced-stage aggressive NHL (e.g., DLBCL); ALL/AML with intermediate WBC; CLL on venetoclax (low tumor burden)
HighBurkitt lymphoma/leukemia, bulky/high WBC ALL or AML, baseline LDH >2× ULN, pre-existing hyperuricemia/renal impairment, renal infiltration, venetoclax in CLL with high tumor burden
Any laboratory or clinical TLS at presentation automatically classifies as high risk.
Source: Cairo MS et al. Br J Haematol 2010;149(4):578–86; BSH 2025 update (Br J Haematol 2025).

③ Surveillance Protocol

RiskMonitoring
Low Routine clinical assessment; labs only if symptoms develop
Intermediate Uric acid, K, phosphate, calcium, creatinine every 12–24h for first 3–4 days of therapy
High Labs every 4–8h (TLS labs + ECG monitoring) for first 24–48h, then every 12–24h; strict fluid balance; continuous cardiac monitoring if K/Ca abnormal
Source: BSH 2025 update, Br J Haematol; Cairo et al. 2010.

④ Management Flowchart

All patients: IV hydration (NSS, no added K), target urine output ≥80–100 mL/m²/h or ~2–3 L/day; avoid nephrotoxins, K/phosphate-containing fluids; correct electrolytes as they trend
↓ risk-stratify
Low risk
Monitor; hydration; allopurinol if any uncertainty
Intermediate risk
Allopurinol up to 7 days + hydration
High risk / established laboratory TLS
Rasburicase + aggressive hydration. Stop allopurinol if switching to rasburicase (concurrent use reduces rasburicase efficacy)
↓ if clinical TLS develops
Clinical TLS: involve Nephrology/ICU early; treat hyperkalemia per ACLS protocol if arrhythmia/ECG changes; consider RRT if refractory hyperkalemia, anuric AKI, refractory hyperphosphatemia, or fluid overload

⑤ Medications

Rasburicase (Fasturtec)
Prophylaxis: 3 mg IV single fixed dose (high-risk adults). Established TLS: 0.2 mg/kg IV once daily, up to 7 days, redose per response
Contraindicated in G6PD deficiency (risk of hemolysis/methemoglobinemia) — screen if at-risk ethnicity/history before first dose.
Allopurinol (Zyloric)
300 mg PO once daily (range 100–300 mg/day); reduce in renal impairment (e.g., 100 mg/day if CrCl <20 mL/min); start 24–48h before chemo if possible
Do not combine with rasburicase — xanthine oxidase inhibition blunts rasburicase substrate availability and adds no benefit.
Febuxostat (Feburic)
120 mg PO once daily — second-line for allopurinol-allergic or G6PD-deficient patients unable to receive rasburicase
MHRA warning: avoid in significant cardiovascular disease.
Urinary alkalinization is not recommended for TLS prophylaxis (promotes calcium phosphate precipitation).
Source: BSH 2025 update, Br J Haematol; NCCN guidelines.