Tumour Lysis Syndrome

Key points

• TLS: massive tumour-cell breakdown — usually triggered by combination chemotherapy for high-grade lymphomas/leukaemias (rarely steroids alone).
• HIGH-risk: IV allopurinol or IV rasburicase immediately before and during first days of chemotherapy.
• Rasburicase = recombinant urate oxidase → uric acid → water-soluble allantoin.
• KEY CONTRAINDICATION: rasburicase must NOT be given in G6PD deficiency — it causes severe haemolysis and methaemoglobinaemia · screen for G6PD deficiency before use, particularly in people of African, Asian or Mediterranean ancestry, and use allopurinol instead.
• Biochemistry: HIGH potassium, HIGH phosphate, HIGH urate and LOW calcium (secondary to the hyperphosphataemia) · acute kidney injury, arrhythmias and seizures are the dangerous consequences · aggressive IV fluids are the mainstay alongside urate-lowering therapy.
• Lower-risk: oral allopurinol during chemotherapy cycles.

Decision points in this pathway

• High risk?

The full step-by-step algorithm, including what to do at each branch, opens in the app for approved members.