13.4 Oncological Emergencies & Palliative Symptom Management

Oncological Emergencies & Palliative Symptom Management

Oncological emergencies are acute, life-threatening complications arising directly from tumor expansion, metabolic dysregulation, or antineoplastic therapy. Palliative medicine provides active, holistic symptom control for advanced progressive malignancy and terminal end-of-life care.

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1. Oncological Emergencies

1. Metastatic Spinal Cord Compression (MSCC)

MSCC occurs in ~5% of all cancer patients, most frequently secondary to osteolytic vertebral metastases from prostate, breast, and lung cancers, followed by renal cell carcinoma, lymphoma, and myeloma. The thoracic spine is the most common anatomical site (~70%), followed by the lumbosacral (~20%) and cervical (~10%) spine.

• Clinical Presentation:
  • Early Warning Sign: Severe, localized, progressive spinal back pain, characteristically worse when lying flat, coughing, straining, or weight-bearing, often disturbing sleep.
  • Radicular Pain: Band-like dermatomal pain radiating around the chest wall or down the limbs.
  • Neurological Signs: Bilateral lower limb motor weakness, hyperreflexia, extensor plantar responses (Babinski sign), and a definitive sensory level.
  • Autonomic Dysfunction (Late Sign): Urinary retention with overflow incontinence, faecal incontinence, or reduced anal sphincter tone. Once sphincter control is lost, the likelihood of regaining ambulation drops drastically.
• Emergency Management Protocol (NICE NG234, 2023, which replaced CG75):
  1. Immediate High-Dose Corticosteroids: Administer oral Dexamethasone 16 mg stat immediately (with oral proton pump inhibitor gastroprotection, e.g. omeprazole 20 mg), followed by 8 mg twice daily. Dexamethasone rapidly reduces vasogenic cord oedema and retards neurological compromise.
  2. Emergency Whole-Spine MRI: Perform an urgent MRI of the entire spine within 24 hours (or within a few hours if progressive motor weakness or sphincter dysfunction is present). Imaging must cover the cervical, thoracic, and lumbar spine because multiple non-contiguous metastases are present in >30% of patients.
  3. Emergency Decompression: Urgent contact with the local MSCC coordinator and spinal surgical team for emergency surgical decompression and stabilization (preferred in solitary metastases with spinal instability), or emergency external beam radiotherapy within 24 hours.

2. Superior Vena Cava Obstruction (SVCO)

Extrinsic compression or secondary intraluminal thrombosis of the thin-walled Superior Vena Cava within the rigid middle mediastinum. Most commonly caused by small cell lung cancer (SCLC), non-small cell lung cancer, and high-grade non-Hodgkin lymphoma.

• Clinical Presentation: Dyspnoea (most common), facial swelling, periorbital puffiness, bilateral arm oedema, headache and dizziness (worse upon bending forward), and distended, non-pulsatile collateral veins over the anterior chest wall and neck. Pemberton's sign is positive (raising both arms above the head for 1 minute precipitates facial plethora, cyanosis, and respiratory distress).
• Emergency Management:
  • Sit the patient upright and deliver supplemental high-flow oxygen.
  • Administer oral Dexamethasone 16 mg daily (with PPI cover) to reduce peritumoral mediastinal oedema.
  • Urgent contrast-enhanced CT thorax to determine anatomical site and vascular patency.
  • Definitive relief: Endovascular SVC stenting provides rapid symptomatic relief (>90% within 24–48 hours), followed by histological confirmation and urgent chemotherapy (for SCLC / lymphoma) or radiotherapy.

3. Neutropenic Sepsis

• Definition (NICE CG151): An absolute neutrophil count <0.5 x 10^9/L (or <1.0 x 10^9/L and rapidly falling) in a patient undergoing systemic antineoplastic chemotherapy, PLUS either:
  • A temperature >38.0°C, OR
  • Any symptoms or clinical signs consistent with systemic sepsis (hypotension, tachycardia, rigors, hypothermia <36.0°C).
• Door-to-Needle Mandate: Door-to-needle time must be <1 hour from initial presentation to the delivery of the first dose of intravenous antipseudomonal broad-spectrum monotherapy.
• Empirical Antibiotic Protocol: Intravenous Piperacillin-tazobactam (Tazocin) 4.5 g every 8 hours. If the patient has a severe penicillin allergy, administer IV Meropenem (or Ciprofloxacin plus Vancomycin).

4. Hypercalcaemia of Malignancy

Occurs in up to 30% of advanced cancers, driven by tumor secretion of Parathyroid Hormone-related Protein (PTHrP) (squamous cell carcinomas of lung, head, neck, oesophagus) or osteolytic bone metastases (breast, myeloma).

• Clinical Presentation: "Stones, bones, abdominal groans, and psychic moans"—fatigue, anorexia, severe nausea, intractable constipation, polyuria, polydipsia, cognitive slowing, confusion, and shortened QT interval on ECG. Severe when corrected serum calcium exceeds 3.0 mmol/L.
• Emergency Management Protocol:
  1. Aggressive Intravenous Hydration: Patients are profoundly volume-depleted from nephrogenic diabetes insipidus. Infuse IV 0.9% normal saline at 3–4 litres over the first 24 hours to restore intravascular volume and promote renal calciuria.
  2. Intravenous Bisphosphonates: Once rehydrated, administer Zoledronic acid 4 mg IV infusion over 15 minutes (or Pamidronate 60–90 mg). Bisphosphonates inhibit osteoclastic bone resorption; maximal normocalcaemic effect occurs at 48–72 hours.
  3. Loop Diuretics Caution: Furosemide is strictly contraindicated during initial resuscitation; it is reserved exclusively for patients who develop fluid overload following aggressive rehydration.
  4. Refractory Cases: Denosumab (monoclonal antibody targeting RANKL) is effective in bisphosphonate-refractory hypercalcaemia or severe renal impairment.

5. Tumour Lysis Syndrome (TLS)

Massive, spontaneous or chemotherapy-induced necrosis of rapidly dividing hematological malignancies (Burkitt lymphoma, ALL, AML).

• Cairo-Bishop Laboratory Criteria (≥2 of the following within 3–7 days of chemotherapy):
  • Hyperkalaemia: K+ >6.0 mmol/L (risk of fatal ventricular arrhythmias)
  • Hyperphosphataemia: PO4 >1.45 mmol/L (precipitates with calcium)
  • Hypocalcaemia: Corrected Ca <1.75 mmol/L (tetany, seizures, QT prolongation)
  • Hyperuricaemia: Uric acid >475 umol/L (precipitates in renal tubules causing AKI)
• Prophylaxis & Therapy:
  • Vigorous IV hydration (3 L/m^2/day).
  • Rasburicase (recombinant urate oxidase): Converts poorly soluble uric acid directly into highly soluble allantoin, rapidly lowering uric acid within 4 hours. Absolute Contraindication: G6PD deficiency (the enzymatic breakdown generates hydrogen peroxide, triggering severe methaemoglobinaemia and haemolysis).
  • Allopurinol: Competitive xanthine oxidase inhibitor used for low/intermediate risk TLS prophylaxis (prevents new uric acid formation but does not degrade existing uric acid).

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2. Palliative Medicine & End-of-Life Symptom Management

The WHO Analgesic Ladder

• Step 1 (Mild Pain): Non-opioid analgesics: Paracetamol (1 g QDS) +/- Non-Steroidal Anti-inflammatory Drugs (NSAIDs, e.g. Ibuprofen or Naproxen, adding PPI cover).
• Step 2 (Moderate Pain): Weak opioid combined with Step 1 non-opioids: Codeine phosphate (30–60 mg QDS), Dihydrocodeine, or Tramadol (50–100 mg QDS).
• Step 3 (Severe Pain): Strong opioids: Morphine sulfate, Oxycodone, or transdermal Fentanyl / Buprenorphine.

Strong Opioid Prescribing & Conversions

• Initiating Strong Opioids: In an opioid-naive patient, start with immediate-release oral morphine (e.g. Oramorph 5–10 mg every 4 hours PRN) or convert to modified-release (MR) morphine (e.g. MST Continus 10–20 mg BD). Co-prescribe a stimulant laxative (e.g. Senna) and an antiemetic (e.g. Haloperidol or Metoclopramide) routinely.
• Breakthrough Pain Calculation: The breakthrough pain dose is usually one-tenth to one-sixth (1/10 to 1/6) of the total 24-hour regular background opioid dose (1/6 is the figure most often used in UK teaching), administered as immediate-release morphine PRN (can be given every 2–4 hours).
• Standard Opioid Conversion Factors:
  • Oral Morphine to Subcutaneous (SC) Morphine: Divide total oral 24-hour dose by 2 (Ratio 2:1).
  • Oral Morphine to Subcutaneous (SC) Diamorphine: Divide total oral 24-hour dose by 3 (Ratio 3:1).
  • Oral Codeine / Tramadol to Oral Morphine: Divide total oral 24-hour dose by 10 (Ratio 10:1).
  • Oral Morphine to Oral Oxycodone: Divide total oral morphine dose by 1.5 to 2 (used when morphine causes intractable neurotoxicity / hallucinations).

Continuous Subcutaneous Infusion (CSCI) Syringe Drivers

When patients enter the terminal phase and lose the ability to swallow oral medications reliably, essential symptom-control medications are combined in a continuous subcutaneous syringe driver over 24 hours:

1. Pain: Continuous subcutaneous infusion of Morphine or Diamorphine.
2. Breathlessness (Dyspnoea): Low-dose subcutaneous Morphine (relieves the sensation of air hunger by blunting brainstem respiratory drive perception) combined with low-dose subcutaneous Midazolam (relieves panic and anxiety).
3. Nausea & Vomiting: Antiemetic selected according to underlying pathophysiology:
   • Chemical / Metabolic / Opioid-Induced (CTZ D2-mediated): Haloperidol (1.5–3 mg/24h SC) or Metoclopramide (30–60 mg/24h SC; prokinetic, avoid in mechanical bowel obstruction).
   • Mechanical Bowel Obstruction / Raised ICP / Vestibular: Cyclizine (150 mg/24h SC; antihistaminic and antimuscarinic).
   • Broad-Spectrum / Refractory Nausea: Levomepromazine (6.25–25 mg/24h SC; blocks dopamine, histamine, and 5-HT receptors).
4. Terminal Respiratory Secretions ("Death Rattle"): Caused by pooled secretions in the hypopharynx in comatose, dying patients unable to cough or clear the airway. Start early before fluid accumulates. First-line: subcutaneous antimuscarinics—Glycopyrronium bromide (200 mcg SC stat PRN or 600–1200 mcg/24h infusion; does not cross the blood-brain barrier, minimizing central sedation/delirium) or Hyoscine butylbromide (Buscopan) (20 mg SC stat PRN or 60–120 mg/24h infusion). Reposition the patient semi-prone or on their side; avoid distressful suctioning.
5. Terminal Agitation & Restlessness: First-line: subcutaneous Midazolam (2.5–5 mg SC stat PRN, or 10–30 mg/24h continuous infusion). For severe delirium or hallucinations: add Levomepromazine or Haloperidol.