What is the recommended approach for inpatient pain management in cancer patients?

Inpatient Pain Management for Cancer Patients

The recommended approach for inpatient pain management in cancer patients involves systematic assessment of pain using standardized tools, followed by a stepwise analgesic therapy based on pain intensity, with regular reassessment and management of side effects. 1, 2

Pain Assessment

• All cancer patients should be evaluated for pain at every clinical encounter using standardized self-reporting tools such as visual analog scales (VAS), numerical rating scales (NRS), or verbal rating scales (VRS) 1, 2

• The key screening question should be: "What has been your worst pain in the last 24 hours on a scale of 0-10?" where 0 is no pain and 10 is the worst imaginable 1

• Comprehensive assessment should include:

  • Pain characteristics: onset, type, site, duration, intensity, temporal patterns, breakthrough episodes 1
  • Presence of trigger factors and relieving factors 1
  • Quality of pain (helps identify pain type):
    • Aching, throbbing: often somatic pain (skin, muscle, bone) 1
    • Cramping, gnawing: often visceral pain (organs) 1
    • Shooting, stabbing, tingling: often neuropathic pain 1
  • Impact on daily activities, sleep, mood, and quality of life 1, 2

• For patients with cognitive impairment, observe pain-related behaviors such as facial expressions, body movements, vocalizations, and changes in interactions 1

Pharmacological Management Based on Pain Intensity

Mild Pain (NRS 1-4)

• Non-opioid analgesics: acetaminophen/paracetamol (maximum 4000 mg/day) or NSAIDs 1, 2
• Provide gastroprotection when using NSAIDs long-term 3

Moderate Pain (NRS 5-7)

• Add weak opioids (codeine, dihydrocodeine, tramadol) to non-opioid analgesics 1, 2
• Alternatively, use low doses of strong opioids such as morphine or oxycodone 1
• Consider controlled-release formulations for stable pain 1

Severe Pain (NRS 8-10)

• Strong opioids: morphine (preferred first-line), hydromorphone, oxycodone, or fentanyl 2, 3
• For opioid-naïve patients, start with lower doses and titrate 1
• For opioid-tolerant patients:
  • Calculate previous 24-hour total requirement
  • For oral administration: administer 10-20% of total daily requirement
  • For IV administration: convert to equivalent dose and administer 10-20% 1

Principles of Opioid Administration

• Provide around-the-clock dosing for persistent pain rather than "as needed" 1, 2
• Include breakthrough doses (typically 10-15% of total daily dose) for transient pain exacerbations 2, 3
• Titrate doses rapidly to achieve effective pain control 2
• For IV morphine, the usual starting dose in adults is 0.1 mg to 0.2 mg per kg every 4 hours as needed, administered slowly 4
• Adjust the baseline opioid regimen if more than four breakthrough doses are needed daily 2
• Convert to oral medications when feasible, including extended-release agents with rescue doses 1

Management of Opioid Side Effects

• Anticipate and proactively manage common side effects 2:
  • Constipation: prophylactic laxatives
  • Nausea/vomiting: antiemetics
  • Central nervous system toxicity: dose reduction or opioid rotation
• Monitor patients with hepatic and renal impairment closely, starting with lower doses and titrating slowly 4

Adjuvant Analgesics

• For neuropathic pain, consider:
  • Anticonvulsants (gabapentin, pregabalin)
  • Antidepressants (tricyclics, SNRIs)
  • Corticosteroids 2, 3
• For bone pain, consider bone-modifying agents (bisphosphonates, denosumab) 2, 3

Non-Pharmacological and Interventional Approaches

• Consider radiation therapy for localized bone pain 2, 3
• Consider surgical stabilization for impending fractures 2, 3
• For pain inadequately controlled despite optimal pharmacologic therapy, consider:
  • Regional infusion of analgesics
  • Nerve blocks
  • Vertebral augmentation 2

Monitoring and Follow-up

• Assess pain during each contact or at least daily for inpatients 1
• Reassess both pain and analgesic side effects regularly 1
• Review analgesic regimen if side effects are present and/or pain persists 1
• Provide written follow-up pain plan, including prescribed medications 1

Common Pitfalls to Avoid

• Underestimating pain severity in patients with cognitive impairment 1
• Failing to recognize that most cancer patients have at least two types of cancer-related pain 1
• Inadequate titration of opioids leading to poor pain control 2
• Not addressing opiophobia in patients and families 1
• Neglecting to provide prophylactic management of opioid side effects 2
• Overlooking the psychosocial impact of pain on patients 1