Expansion
Neutropenic sepsis, tumour lysis, spinal cord compression and hypercalcaemia
Mnemonic
Four emergencies, each with a defining feature:
- Neutropenic sepsis - fever or any deterioration within 6 weeks of chemotherapy. Antibiotics within 1 hour, before the neutrophil count is known. The commonest and most lethal
- Tumour lysis syndrome - high potassium, high phosphate, high urate, low calcium, with acute kidney injury. Occurs in bulky, chemosensitive tumours. Prevented by hydration and allopurinol or rasburicase
- Metastatic spinal cord compression - back pain with neurology. Dexamethasone and whole spine MRI within 24 hours
- Superior vena cava obstruction - facial swelling, distended neck and chest veins, Pemberton’s sign. Usually lung cancer or lymphoma. Needs urgent imaging and stenting
“High everything except calcium” identifies tumour lysis, because phosphate binds calcium.
Hypercalcaemia of malignancy is the fifth, treated with fluids then bisphosphonates.
Neutropenic sepsis is the one where waiting for a result kills, and the mortality falls sharply with door to antibiotic time.
Expansion
- Neutropenic sepsis: temperature above 38 or clinical sepsis with a neutrophil count below 0.5. Give broad spectrum antibiotics, usually piperacillin-tazobactam, within one hour. Do not wait for the count or for cultures to result
- Tumour lysis syndrome: after treating bulky, rapidly dividing tumours. Hyperkalaemia, hyperphosphataemia, hyperuricaemia and hypocalcaemia with acute kidney injury. Prevent with hydration and allopurinol or rasburicase
- Metastatic spinal cord compression: back pain with neurological signs. Give dexamethasone immediately and arrange urgent whole spine MRI; delay costs function
- Hypercalcaemia of malignancy: rehydrate aggressively with saline, then bisphosphonate
- Superior vena cava obstruction: facial swelling, distended veins, dyspnoea. Steroids and stenting or radiotherapy
- Extravasation of a vesicant such as an anthracycline or vinca alkaloid: stop the infusion, aspirate, and follow the specific antidote protocol
- Raised intracranial pressure from cerebral metastases
Two rules cut across all of them: neutropenic sepsis and cord compression are the two where minutes and hours change outcome, and any unwell patient within 6 weeks of chemotherapy should be assumed to be neutropenic until proven otherwise.