What is the protocol for pain management in patients with acute or chronic pain?

Pain Management Protocol

Initial Assessment and Pain Severity Classification

For acute and chronic pain management, begin with rapid pain assessment using validated scales (Visual Analog Scale, Numeric Rating Scale 0-10, or Verbal Rating Scale), then implement stepwise pharmacologic therapy based on pain severity, with acetaminophen or NSAIDs as first-line for mild-to-moderate pain and opioids reserved for severe pain or failure of non-opioid therapy. 1

Pain Assessment Tools

• Use patient self-report with NRS (0-10 scale) or VAS as primary assessment method 1
• For non-communicative elderly or cognitively impaired patients, observe facial expressions (grimacing, frowning, closed eyes), vocalizations (moaning, groaning), body movements (guarding, rigidity), behavioral changes (aggression, withdrawal), and activity pattern changes 1
• Apply specialized tools: Pain Assessment in Advanced Dementia (PAINAD), Critical Care Pain Observation Tool (CPOT), or Behavioral Pain Scale (BPS) for non-verbal patients 1

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Stepwise Pharmacologic Protocol

Step 1: Mild Pain (NRS 1-4)

First-line treatment is acetaminophen 500-1000 mg every 6 hours (maximum 4000-6000 mg/day) or NSAIDs such as ibuprofen 400-600 mg every 6-8 hours (maximum 2400 mg/day). 1

• Acetaminophen is preferred initially due to fewer side effects than NSAIDs 1
• Ibuprofen 400 mg is the safest NSAID option with optimal risk-benefit profile 2
• For musculoskeletal pain specifically, acetaminophen and NSAIDs are recommended as first-line agents 1
• Consider ibuprofen/acetaminophen fixed-dose combinations as effective opioid-sparing alternatives 3

Key precautions:

• Reduce acetaminophen dosing in liver disease 1
• Co-prescribe proton pump inhibitors with NSAIDs in elderly patients, especially those on ACE inhibitors, diuretics, or antiplatelets 1
• NSAIDs should be used cautiously in elderly due to acute kidney injury and gastrointestinal risks 1
• COX-2 selective NSAIDs (celecoxib) have decreased GI risk but increased cardiovascular risk 1

Step 2: Moderate Pain (NRS 5-7)

Combine acetaminophen (up to 4000 mg/day) with a weak opioid (codeine up to 240 mg/day, tramadol, or low-dose strong opioids like morphine or oxycodone) or escalate NSAID therapy. 1

• Tramadol 37.5-400 mg daily in divided doses may be used for up to 3 months for conditions like osteoarthritis 1
• Controlled-release formulations of codeine, tramadol, morphine, or oxycodone improve convenience for moderate pain 1
• Low-dose transdermal fentanyl or buprenorphine are additional options 1

Important caveat: Codeine, propoxyphene, and tramadol have shown poor efficacy and significant side effects in some acute pain studies 2

Step 3: Severe Pain (NRS 8-10)

Potent opioids (morphine, hydromorphone, oxycodone, or fentanyl) are indicated for severe pain, administered via scheduled around-the-clock dosing or patient-controlled analgesia rather than as-needed dosing. 1

Opioid Selection and Dosing:

• Morphine remains the cornerstone for severe trauma and cancer pain 1
• Intravenous morphine or fentanyl for acute severe pain in emergency settings 1
• Oxycodone: initiate at 5-15 mg every 4-6 hours for opioid-naïve patients; titrate based on response 4
• For chronic severe pain, administer opioids on fixed schedule every 4-6 hours to prevent pain recurrence rather than treating after onset 4

Critical Monitoring:

• Monitor respiratory rate, oxygen saturation, blood pressure, and level of consciousness closely, especially within first 24-72 hours of initiation or dose increases 1, 4
• Have naloxone immediately available for respiratory depression 5
• Avoid mixed agonist-antagonists (pentazocine, nalbuphine, butorphanol) as they may precipitate withdrawal in opioid-tolerant patients 5

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Special Populations and Situations

Patients on Methadone Maintenance

Continue the patient's usual daily methadone dose without interruption and add short-acting opioids (morphine, hydromorphone, oxycodone) at higher doses and more frequent intervals (every 3-4 hours) than for opioid-naïve patients due to cross-tolerance. 5

• Split methadone into 6-8 hour doses for continuous analgesia, adding 5-10% of current dose for afternoon/evening (total 10-20% increase) 1, 5
• Provide rescue doses equivalent to 10-15% of total daily dose for breakthrough pain 5
• Verify maintenance dose with patient's clinic before treatment and notify them of hospitalization and any controlled substances prescribed 5
• Use multimodal approach with aggressive non-opioid analgesia (NSAIDs, acetaminophen, adjuvants) to reduce total opioid requirements 5

Patients on Buprenorphine

Continue buprenorphine at current dose and add short-acting full opioid agonists at higher-than-usual doses with scheduled (not as-needed) dosing. 5

• For severe acute pain, consider temporarily discontinuing buprenorphine and using full opioid agonists, then converting back when acute pain resolves 5
• Higher doses of additional opioids may be needed due to buprenorphine's high mu-receptor binding affinity blocking lower opioid doses 1
• If maximal buprenorphine dose (16 mg divided into 8-hour doses) is ineffective, add long-acting potent opioids (fentanyl, morphine, hydromorphone) 1

Elderly and Frail Patients

Administer intravenous acetaminophen 1000 mg every 6 hours as first-line unless contraindicated; avoid NSAIDs in perioperative hip fracture management due to kidney injury and GI risks. 1

• Elderly patients are particularly vulnerable to opioid-induced over-sedation, respiratory depression, and accumulation 1
• Use opioids cautiously with close monitoring for cardiovascular events, nausea/vomiting, and respiratory failure 1

Cancer Pain

Over 80% of advanced cancer patients require pain management; assess pain at every visit and escalate therapy according to WHO ladder principles. 1

• Pain should be managed during diagnostic evaluation, not delayed 1
• Incorporate primary antitumor treatments alongside systemic analgesics 1
• Approximately 20% of cancer pain results from treatment effects (surgery, radiotherapy, chemotherapy) 1

Sickle Cell Disease

Many uncomplicated pain episodes can be managed at home with oral fluids, rest, heat, full-dose oral analgesics (mild opioids plus NSAIDs), and non-pharmacologic methods. 1

• When home management fails, provide rapid triage and aggressive parenteral analgesia (morphine via scheduled dosing or PCA) 1
• Maintain adequate hydration, monitor oxygenation, use incentive spirometry, and observe for acute chest syndrome 1
• Avoid stigmatizing patients or delaying treatment; pain in SCD should be treated aggressively according to predetermined personalized plans 1

HIV-Associated Neuropathic Pain

Opioids should not be prescribed as first-line for chronic neuropathic pain in people living with HIV; use gabapentin, pregabalin, or tricyclic antidepressants first. 1

• Consider time-limited opioid trial only for moderate-to-severe pain unresponsive to first-line therapies, starting with smallest effective dose combining short- and long-acting formulations 1
• Combination morphine and gabapentin may have additive effects allowing lower individual doses 1
• Alpha lipoic acid is recommended for HIV-associated peripheral neuropathic pain 1
• Avoid lamotrigine for HIV neuropathic pain due to rash risk and limited benefit 1

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Multimodal Adjunctive Strategies

Non-Opioid Adjuvants

• Use adjuvant medications appropriate to pain syndrome: gabapentin/pregabalin for neuropathic pain, NSAIDs for inflammatory pain, tricyclic antidepressants for potentiation 1
• Topical agents, steroids, and non-pharmacologic treatments (heat, cold, physical therapy, psychological interventions) enhance analgesia 1

Breakthrough Pain Management

• Provide small amounts of short-acting opioids for breakthrough pain in low-risk patients, with agreed-upon pill counts, frequency, and duration 1
• Rescue doses should equal 10-15% of total daily opioid dose 5
• Increase base dose if more than four rescue doses needed per day 5

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Critical Safety Considerations

Opioid Prescribing Precautions

• Assess all patients for risk of opioid misuse, diversion, and addiction prior to prescribing; use lowest effective dose for shortest duration 1, 4
• Prescribe opioids only when potential benefits for pain severity, physical function, and quality of life outweigh harms 1
• Use scheduled fixed-interval dosing rather than as-needed to prevent pain recurrence and reduce patient anxiety 5, 4
• Avoid fixed-dose acetaminophen combinations in patients requiring high opioid doses due to hepatotoxicity risk 5

Common Pitfalls to Avoid

• Do not under-treat pain due to fear of addiction ("opiophobia"); distinguish pain-related drug-seeking from true addiction 1, 5
• Do not confuse therapeutic dependence (fear of pain/withdrawal reemergence) with addiction 5
• Do not allow pain to recur before next scheduled dose, causing unnecessary suffering 5
• Explicitly reassure patients with addiction history that their pain will be adequately managed and maintenance therapy will continue 5