Cancer Emergencies

Febrile Neutropenia - Fever Pitch Peril

• Definition: Fever (single oral T ≥ 38.3°C or T ≥ 38.0°C sustained ≥1 hr) + Neutropenia (ANC < 500/mm³ or ANC < 1000/mm³ with predicted fall to < 500/mm³).
• Risk Stratification: MASCC score (Multinational Association for Supportive Care in Cancer); score ≥21 indicates low risk, consider outpatient management.
• Common Pathogens: Gram-negative bacilli (Pseudomonas aeruginosa, E. coli), Gram-positive cocci (Staphylococcus aureus, Streptococcus spp.).
• Management: Initiate empiric broad-spectrum antibiotics within 60 minutes.

⭐ The "golden hour": Administer empiric broad-spectrum antibiotics within 60 minutes of presentation to significantly reduce mortality risk in febrile neutropenia patients.

Tumor Lysis Syndrome - Cell Chaos Crisis

Rapid cell lysis releases intracellular contents. High risk: Burkitt, ALL/AML, bulky tumors post-chemo. 📌 Mnemonic: K-PUNCH (K⁺↑, Phosphate↑, Uric acid↑, Nucleotides↑, Ca²⁺↓, Hydration).

• Lab TLS (Cairo-Bishop):
  • Uric acid >8 mg/dL
  • K⁺ >6 mEq/L
  • PO₄³⁻ >4.5 mg/dL
  • Ca²⁺ <7 mg/dL
• Clinical TLS: Lab TLS + AKI (Cr >1.5x ULN), arrhythmia, seizure.
• Management:
  • Aggressive IV hydration (2-3 L/m²/day).
  • Allopurinol; Rasburicase (0.2 mg/kg) if high-risk/uric acid ↑↑.
  • Correct electrolytes; dialysis if needed.

  ⭐ Rasburicase is contraindicated in G6PD deficiency due to risk of severe hemolysis.

Spinal Cord Compression - Nerve Wreckage

Oncologic emergency from tumor pressure on spinal cord/cauda equina.

• Etiology: Lung, breast, prostate cancer; myeloma, lymphoma.
• Clinical:
  • Back pain (>90%): Earliest, worse supine/night, radicular.
  • Motor weakness, sensory deficits (progressive).
  • Autonomic dysfunction (late): Bladder/bowel.
• Diagnosis: MRI whole spine (gold standard).
• Management:

- Steroids: Dexamethasone (e.g., **10 mg** IV bolus, then **4-6 mg** q6h or higher doses like **16-96 mg/day**).
- Definitive: RT, surgery, or chemo based on tumor/stability.

⭐ Back pain is the earliest symptom (>90%), often preceding neurological deficits by weeks. Prompt MRI is crucial.

Hypercalcemia of Malignancy - Calcium Calamity

• Serum Ca > 10.5 mg/dL (ionized > 1.3 mmol/L). Severe: > 14 mg/dL.
• Pathophys: PTHrP (80%, squamous cell Ca), local osteolysis (breast Ca, myeloma), ↑Vit D (lymphoma).
• Sx: 📌 "Stones, bones, groans, thrones, psychiatric overtones". ECG: Short QT.
• Rx:
  • Initial: IVF (NS 3-6L/24h). Furosemide post-IVF.
  • Specific: Bisphosphonates (Zoledronate 4mg IV). Calcitonin (rapid ↓Ca). Denosumab (refractory).

⭐ Bisphosphonates (e.g., Zoledronic acid) are cornerstone; onset 2-4 days, nadir 4-7 days.

Superior Vena Cava Syndrome - Vascular Vexation

Obstruction of SVC blood flow, often by external compression or internal thrombosis.

• Etiology:
  • Malignancy (~90%): Lung cancer (esp. SCLC), lymphoma, metastases.
  • Benign: Catheter-related thrombosis, fibrosing mediastinitis.
• Features: 📌 "3 D's": Dyspnea, Distended neck/chest veins, Disfigurement (facial/arm edema, plethora). Pemberton's sign.
• Diagnosis: CT chest with contrast. Histopathology essential.
• Management:
  • Supportive: Head elevation, O2, corticosteroids (e.g., dexamethasone).
  • Definitive: RT, chemotherapy, SVC stenting for rapid relief.

⭐ SCLC is a frequent malignant cause of SVCS.

High‑Yield Points - ⚡ Biggest Takeaways

• Febrile neutropenia: ANC < 500/µL + fever. Immediate broad-spectrum antibiotics are crucial.
• Tumor Lysis Syndrome (TLS): Key features: hyperkalemia, hyperuricemia, hyperphosphatemia, hypocalcemia. Prophylaxis/treatment: hydration, allopurinol/rasburicase.
• SVC Syndrome: Facial/arm swelling, dyspnea. Common with lung cancer. Treat with steroids, radiotherapy.
• Spinal Cord Compression: Back pain, weakness. MRI is diagnostic. Immediate steroids, radiotherapy/surgery.
• Hypercalcemia of Malignancy: Most common paraneoplastic. Treat with hydration, bisphosphonates, calcitonin.
• SIADH: Euvolemic hyponatremia, often with SCLC. Management: fluid restriction.