Tumour Lysis Syndrome 🧬

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🚨 Definition & Recognition

  • Metabolic emergency caused by rapid lysis of tumour cells, releasing intracellular contents into circulation
  • Typically occurs within 12-72 hours after starting chemotherapy (can occur spontaneously)
  • Characterized by: Hyperuricaemia, Hyperkalaemia, Hyperphosphataemia, Hypocalcaemia
  • Can lead to acute kidney injury, cardiac arrhythmias, seizures, and death if untreated
  • Medical emergency - requires immediate intervention

⚠️ High-Risk Patients

  • High tumour burden: Burkitt lymphoma, ALL, AML (especially high WCC >50 x 10⁹/L)
  • Aggressive lymphomas: DLBCL, T-cell lymphomas
  • Pre-existing renal dysfunction or elevated baseline uric acid
  • Dehydration or poor urine output
  • High sensitivity tumours: Small cell lung cancer, germ cell tumours
  • Patients receiving fludarabine, cladribine, or other high-risk regimens

⚡ Immediate Actions (First Hour)

  • ABC assessment and continuous cardiac monitoring (risk of arrhythmias)
  • IV access and start aggressive IV hydration: 3L/m²/day minimum
  • U&E, uric acid, phosphate, calcium, LDH immediately
  • FBC, magnesium, LFTs, coagulation
  • ECG (risk of hyperkalaemia-induced arrhythmias)
  • Hourly urine output monitoring (target >100ml/hr)
  • Notify oncology/haematology team immediately
  • Consider ICU admission if severe or worsening

📊 Diagnostic Criteria (Cairo-Bishop)

  • Laboratory TLS: 2 or more of the following within 3 days of treatment:
  • • Uric acid >476 μmol/L (8mg/dL) or 25% increase
  • • Potassium >6.0 mmol/L or 25% increase
  • • Phosphate >1.45 mmol/L (adults) or >2.1 mmol/L (children) or 25% increase
  • • Calcium <1.75 mmol/L or 25% decrease
  • Clinical TLS: Laboratory TLS + one of:
  • • Creatinine >1.5x ULN or oliguria (<0.5ml/kg/hr for 6 hours)
  • • Cardiac arrhythmia/ sudden death
  • • Seizure

💊 Prevention (High-Risk Patients)

  • Start 24-48 hours BEFORE chemotherapy:
  • • IV hydration: 3L/m²/day (or 125-150ml/hr)
  • • Allopurinol: 300mg PO daily (reduce dose if eGFR <30)
  • • Consider rasburicase if uric acid >476 μmol/L or high risk
  • Monitor U&E, uric acid, phosphate, calcium daily
  • Maintain urine output >100ml/hr with IV fluids and diuretics if needed
  • Avoid potassium/phosphate supplements

🩺 Treatment (If TLS Develops)

  • IV Hydration: Aggressive 3-4L/m²/day (125-200ml/hr) to maintain high urine output
  • Rasburicase: 0.15-0.2mg/kg IV once daily (reduces uric acid rapidly)
  • • Check G6PD deficiency before use (risk of haemolysis)
  • • Usually 1-3 days, monitor uric acid daily
  • Allopurinol: 300mg PO daily (if rasburicase not available or as adjunct)
  • Hyperkalaemia: Treat aggressively - see hyperkalaemia protocol
  • • Calcium gluconate 10ml 10% IV (cardiac protection)
  • • Insulin/dextrose, salbutamol, consider dialysis
  • Hyperphosphataemia: Phosphate binders (calcium carbonate/sevelamer), restrict phosphate
  • Hypocalcaemia: Only treat if symptomatic or severe - avoid overcorrection
  • Monitor closely: U&E, uric acid, phosphate, calcium every 6-12 hours initially

📋 Monitoring

  • Baseline: U&E, uric acid, phosphate, calcium, LDH, FBC, ECG
  • During prophylaxis: Daily U&E, uric acid, phosphate, calcium
  • If TLS develops: U&E, uric acid, phosphate, calcium every 6-12 hours
  • Continuous cardiac monitoring (hyperkalaemia risk)
  • Hourly urine output (target >100ml/hr)
  • Daily weight, fluid balance
  • Regular ECG (monitor for arrhythmias)
  • Continue monitoring for 48-72 hours post-chemotherapy

⚠️ Red Flags - Escalate Immediately

  • ECG changes: Peaked T-waves, prolonged PR, wide QRS (hyperkalaemia)
  • Cardiac arrhythmias or sudden deterioration
  • Seizures or altered consciousness
  • Oliguria/anuria or rising creatinine
  • Uric acid >600 μmol/L despite treatment
  • Severe electrolyte abnormalities not responding to treatment
  • Signs of fluid overload (pulmonary oedema)

🏥 Renal Replacement Therapy

  • Indications for dialysis:
  • • Severe AKI (creatinine >3x baseline or oliguria/anuria)
  • • Hyperkalaemia >6.5 mmol/L despite medical treatment
  • • Severe hyperphosphataemia causing symptoms
  • • Fluid overload with pulmonary oedema
  • • Metabolic acidosis refractory to treatment
  • Early nephrology consult recommended if AKI developing
  • Rasburicase can reduce need for dialysis if given early

🔗 Related Topics

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