Emergencies, Complications and Oncologic Urgencies
What this domain tests
This domain tests time-critical recognition and first-line management. Questions give a deteriorating patient and expect a specific action within a defined time window and a specific drug dose.
Core rules
- Febrile neutropenia: temperature 38.3 °C once or 38.0 °C sustained over one hour, with neutrophils below 0.5 × 10⁹/L (or expected to fall below). Take cultures and give empirical broad-spectrum antipseudomonal beta-lactam antibiotics within one hour. A MASCC score of 21 or more identifies low-risk patients who may be managed as outpatients.
- Metastatic spinal cord compression: back pain, motor weakness, sensory level and sphincter disturbance. Give dexamethasone 16 mg daily, obtain whole-spine MRI within 24 hours, and refer for surgical decompression if there is a single compressive level, radiosensitive-independent histology, and prognosis beyond three months; otherwise radiotherapy.
- Tumour lysis syndrome (Cairo-Bishop): two or more of uric acid 476 µmol/L or more, potassium 6.0 mmol/L or more, phosphate 1.45 mmol/L or more, calcium 1.75 mmol/L or less within three days before or seven days after treatment. Add creatinine 1.5 times the upper limit of normal or higher, seizure or arrhythmia for clinical TLS. Treat with vigorous hydration, allopurinol for prophylaxis and rasburicase for established hyperuricaemia (contraindicated in G6PD deficiency).
- Hypercalcaemia: correct calcium for albumin, give intravenous isotonic saline, then a bisphosphonate or denosumab.
- Superior vena cava obstruction: sit the patient upright, give oxygen, obtain CT, and consider urgent radiotherapy, stenting or chemotherapy for chemosensitive tumours.
Worked example
A patient with Burkitt lymphoma has a potassium of 6.3 mmol/L, phosphate 1.6 mmol/L, uric acid 520 µmol/L and creatinine 1.6 times the upper limit of normal after starting chemotherapy. Reasoning: four metabolic abnormalities plus renal impairment meet Cairo-Bishop criteria for clinical TLS. Immediate actions are cardiac monitoring, intravenous hydration, rasburicase after G6PD testing, and holding nephrotoxins; dialysis is indicated for refractory hyperkalaemia or oliguric renal failure.
Traps
Waiting for the neutrophil count before giving antibiotics; using dexamethasone before imaging in cord compression without a plan; giving rasburicase in G6PD deficiency; forgetting to correct calcium for albumin.