Key Facts

Pain management in palliative care requires regular assessment, individualised treatment, and attention to all dimensions of suffering.

Epidemiology

• Pain affects 50% at diagnosis and 70-80% with advanced cancer
• 10-20% have refractory pain requiring specialist intervention
• Non-cancer conditions also cause significant pain: heart failure, COPD, renal failure, neurological disease

Aetiology

• Cancer-related (60-70%): direct tumour involvement (bone, nerve, visceral, soft tissue)
• Treatment-related (20%): post-surgical, chemotherapy-induced neuropathy, radiation fibrosis
• Concurrent (10-20%): musculoskeletal, neuropathic, non-related conditions

Pathophysiology

• Nociceptive (somatic): well-localised, aching; bone, soft tissue
• Nociceptive (visceral): poorly localised, cramping, referred; organ involvement
• Neuropathic: burning, shooting, allodynia; nerve compression/invasion
• Mixed: combination of mechanisms (very common in cancer pain)
• Bone pain: osteoclast activation → bone destruction → nociceptor stimulation; prostaglandin-mediated

Pain Assessment

• Location, character, severity (0-10 NRS)
• Temporal pattern: constant, intermittent, incident, breakthrough
• Radiation and referral patterns
• Aggravating and relieving factors
• Impact on function, sleep, mood
• Current analgesic use and effectiveness
• Side effects of treatment

Pain Types in Palliative Care

• Background pain: constant, present most of the time
• Breakthrough pain: transient flare on controlled background (spontaneous or incident-related)
• Incident pain: predictable, related to specific activity (movement, dressing change)
• End-of-dose pain: pain returning before next scheduled dose

Red Flags

• Back pain with neurological signs (spinal cord compression — emergency)
• Severe uncontrolled pain despite escalating opioids
• Opioid toxicity: myoclonus, confusion, hallucinations, respiratory depression
• Pain crisis (severe uncontrolled pain requiring emergency management)

Bedside

• Pain assessment (NRS, body map, Brief Pain Inventory)
• Neurological examination if neuropathic component
• Medication chart review

Bloods

• U&Es (renal function for opioid dosing)
• Calcium (hypercalcaemia causing pain)
• LFTs (hepatic metabolism)

Imaging

• Targeted imaging of pain site (X-ray, CT, MRI)
• MRI spine: if cord compression suspected (emergency)

Special Tests

• Specialist pain assessment if refractory
• Psychological assessment (pain catastrophising, depression)

Non-pharmacological

• Patient education about pain management goals
• Psychological support (CBT, relaxation, mindfulness)
• Physiotherapy (gentle exercise, positioning)
• TENS (adjunct for localised pain)
• Heat/cold therapy
• Complementary therapies (massage, acupuncture)

Pharmacological

• Step 1: paracetamol 1g QDS ± NSAID (ibuprofen 400mg TDS or naproxen 250-500mg BD — with PPI cover)
• Step 2: codeine 30-60mg QDS or tramadol 50-100mg QDS (increasingly bypassed in favour of low-dose strong opioid)
• Step 3:
  • Oral morphine: 5-10mg IR 4-hourly; titrate by 30-50% every 24-48 hours until pain controlled
  • Convert to MR: total 24h IR dose → divide by 2 for BD MR dosing (MST Continus, Zomorph)
  • Breakthrough: 1/6th of 24-hour morphine dose, IR, PRN up to hourly
  • Oxycodone: alternative; start 5mg IR 4-6 hourly or 10mg MR BD (equianalgesic: oral morphine:oxycodone = 1.5-2:1)
  • Fentanyl patch: 12-25mcg/h every 72 hours (stable pain, swallowing difficulty)
  • Buprenorphine patch: 5-70mcg/h every 7 days
• Adjuvants:
  • Neuropathic: amitriptyline 10-75mg ON; gabapentin 300-1,800mg/day; pregabalin 75-300mg BD
  • Bone: NSAID ± dexamethasone 4-8mg OM; zoledronic acid 4mg IV monthly or denosumab 120mg SC monthly
  • Muscle spasm: baclofen 5-20mg TDS; diazepam 2-5mg TDS
  • Visceral colic: hyoscine butylbromide 20mg QDS
• Always co-prescribe: laxatives (senna 15mg ON + docusate 100mg BD); antiemetic PRN (metoclopramide 10mg TDS or haloperidol 1.5mg ON)

Surgical/Interventional

• Palliative radiotherapy: bone mets (8Gy single fraction — 60-80% response)
• Nerve blocks: coeliac plexus (pancreatic), paravertebral, intercostal
• Intrathecal drug delivery: refractory pain (morphine ± bupivacaine ± ziconotide)
• Vertebroplasty/kyphoplasty: painful vertebral fractures
• Cordotomy: unilateral cancer pain (specialist centres)

Referral Criteria

• Pain not controlled with Step 3 opioids + adjuvants: specialist palliative care
• Neuropathic pain not responding to first-line: pain specialist
• Interventional procedures needed: pain team
• Opioid toxicity or difficulty with rotation: specialist input

• >80% of cancer pain can be controlled with WHO ladder + adjuvants
• 10-20% have refractory pain requiring specialist intervention
• Palliative RT for bone pain: response in 60-80%; complete response in 30%
• Good pain management significantly improves quality of life, function, and mood
• Untreated pain is associated with depression, anxiety, and reduced survival

WHO Analgesic Ladder

Opioid Equianalgesic Doses