see: [Dunn - other oncologic emergencies](x-devonthink-item://2CB10C13-DD29-4E8A-A9BF-560FC57E7AB8)
> [!key points]
> - combination of [[hyperkalemia]], hyperuricaemia, hyperphosphatemia, and [[Hypocalcemia]], often accompanied by [[Acute Renal Failure]]
> - tx with IVF and therapies to reverse hyper-k
> - hyperuricemia may be prevented with allopurinol or tx with *rasburicase*
> - calcium should only be replaced in pts with cardiac or neurologic manifestations of hypocalcaemia (eg seizures)
![[Pasted image 20240821113750.png]]
- occurs when destruction of malignant cells occurs so rapidly that body's mechanisms for regulating the unwanted products of their destruction are overwhelmed
- patients undergoing *cytotoxic therapy* are particularly at risk for TLS
- most common from haematological malignancies:
- burkit's lymphoma (hyperuricaemia and LDH 1500 ∝ total tumor burden
- [[Leukemia|ALL]]
**Risk factors**
- large tumor burden / bulky tumour mass
- extensive marrow involvement
- high tumor sensitivity to chemotherapeutic agents
- haematological malignancies eg ALL, Burkitt lymphoma
- pre-existing renal failure
- glucocorticoids, hormonal agents (lletrozole/ tamoxifen), monoclonal antibiodies (rituximab / gemtuzumab), ionizing radiation
- use of chemotherapy eg. cisplatin, etoposide, fludarabine, intrathecal methotrexate, paclitaxel
- LDH > 1500 IU
- dehydration / volume depletion
- pre-treatment hyperuricaemia
- pre-treatment hyperphosphataemia
- WCC > 50,000
- first chemo dose
**Biochemical findings**
- [[hyperkalemia]]
- hyperphosphataemia → release of intracellular phosphate
- hyperuriceamia
- [[Hypocalcemia]] → reciprocal from the ↑ PO4
- [[Acute Renal Failure]] / ↑ creatinine and urea
- [[Lactic acidosis]]
lactic acidosis and dehydration may contribute to the precipitation of uric acid in the renal tubules; ∴ urinalysis may show uric acid crystals.
urinary uric acid: urinary creatine ratio is > 1 in pts with acute hyperuricaemic nephropathy
**Complications**
- AKI
- tetany
- arrhythmias
**Treatments**
| tx | mechanism |
| ------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------ |
| IV hydration | - improve dehydration as cause of renal failure<br>- uric acid excretion |
| insulin/dextrose | shift K intracellularly |
| beta agonist nebs | shift K intracellularly |
| [[Calcium Gluconate]] | replenish Ca in symptomatic (eg [[Seizures]]) ↓ Ca |
| rasburicase<br>{recombinant urate oxidase) | enhance uric acid elimination |
| [[HCO3 therapy\|sodium bicarb]] | urinary alkalinisation to ↑ uric acid solubility and excretion -- only in presence of of metabolic acidosis<br>- can also help shift K intracellularly |
| [[haemodialysis\|dialysis]] | treat [[hyperkalemia\|hyper-K]] and ↑ PO4, support renal f(x) |
| allopurinol | decrease uric acid production; pre-treatment |
| +/- frusemide | another agent to help clear K in fluid overload |