oncologic emergencies

Structural & Cellular Crises

Mechanical or metabolic complications requiring immediate intervention to preserve organ function (Brain, Lungs, Kidneys, Spine).

leukostasis

• Definition: Extreme leukocytosis (usually WBC > 100) causing microvascular sludging.
• Risk: AML > ALL > CML.
• Clinical:
  • Pulmonary: Hypoxia, dyspnoea (mimics ARDS).
  • CNS: Confusion, somnolence, intracranial haemorrhage.
• Management:
  1. Cytoreduction: High-dose chemotherapy (e.g., Hydroxyurea) is the mainstay.
     • Note on Leukapheresis: Controversial. May temporarily lower counts in symptomatic patients but limited evidence for survival benefit. Do not delay chemotherapy for pheresis.
  2. Supportive: Aggressive hydration. Avoid pRBC transfusion (increases viscosity) unless absolutely necessary.

hypercalcemia of malignancy

• Pathophysiology: PTH-rp secretion or extensive lytic bone mets (Myeloma).
• Management Goals:
  1. Volume Expansion (Key): Aggressive IV NS to drive renal Ca excretion.
     • Target: Initial rate 200-300 mL/hr (Aim for 4–6L total over 24h).
     • Goal: Urine output 100–150 mL/hr.
  2. Bone Resorption Block: Pamidronate or Zoledronic Acid (IV Bisphosphonates). * These take days (24-72h) to work.*
  3. Refractory: Calcitonin (tachyphylaxis occurs quickly), Steroids, or Dialysis.

spinal cord compression

• Signs: Back pain (worse lying down), motor weakness, sensory level, bowel/bladder retention (late).
• Immediate Action:
  1. Steroids: Dexamethasone 10 mg IV STAT, then 4 mg IV/PO q6h.
  2. Imaging: Urgent MRI Spine (entire spine).
  3. Definitive: Urgent Radiation Oncology or Neurosurgery consult.