What are the management options for chronic pain syndrome?

Chronic Pain Syndrome: Diagnosis and Management

Diagnostic Criteria

Chronic pain syndrome is defined as pain persisting beyond 3 months that represents a distinct disease entity characterized by biological, psychological, and social factors rather than merely a symptom of underlying pathology. 1, 2

Essential Diagnostic Components

Pain Assessment:

• Minimum screening should include: "How much bodily pain have you had during the last week?" (none, very mild, mild, moderate, severe, very severe) and "Do you have bodily pain that has lasted for more than 3 months?" 1
• Use the ultra-brief PEG tool (Pain intensity, interference with Enjoyment of life, interference with General activity) for rapid assessment in busy clinical settings 1
• Document pain location, quality, severity, temporal patterns, and aggravating/relieving factors 1

Functional Impact Assessment:

• Evaluate impact on activities of daily living, sleep, mood, and interpersonal relationships 1
• Assess physical and emotional function rather than focusing solely on pain severity, as functional impairment often affects quality of life more than pain intensity itself 1

Psychosocial Evaluation:

• Screen all patients for depression using two questions: "During the past 2 weeks have you often been bothered by feeling down, depressed, or hopeless?" and "During the past 2 weeks have you been bothered by little interest or pleasure in doing things?" 1
• Assess for anxiety, psychiatric disorders, coping mechanisms, history of trauma or abuse, and substance use 1
• Evaluate family, vocational, and legal issues 1

Pain Mechanism Classification:

• Categorize as nociceptive (tissue damage), neuropathic (nerve injury), or nociplastic (central sensitization) to guide treatment selection 3, 2
• Recognize that multiple pain mechanisms often overlap in individual patients 3

---

Management Strategy

Chronic pain requires a multimodal, interdisciplinary approach combining non-pharmacological interventions as first-line treatment, with pharmacotherapy tailored to pain mechanism and patient-specific factors. 1, 4

First-Line Non-Pharmacological Interventions

Cognitive Behavioral Therapy (CBT):

• CBT is strongly recommended for chronic pain management (strong recommendation, moderate quality evidence) 1
• Promotes acceptance of responsibility for change, develops adaptive behaviors (e.g., exercise engagement), and addresses maladaptive behaviors (e.g., activity avoidance due to pain fears) 1
• Helps develop coping strategies for anxiety related to current and future pain 1

Physical Modalities:

• Yoga is strongly recommended for chronic neck/back pain, headache, rheumatoid arthritis, and general musculoskeletal pain (strong recommendation, moderate quality evidence) 1, 5
• Physical and occupational therapy are strongly recommended for chronic pain (strong recommendation, low quality evidence) 1, 5
• Exercise programs improve physical functioning and should be incorporated into treatment plans 4

Additional Non-Pharmacological Options:

• Hypnosis is strongly recommended specifically for neuropathic pain (strong recommendation, low quality evidence) 1
• Acupuncture may be considered as a trial for chronic pain (weak recommendation, moderate quality evidence) 1
• Patient education on pain neurophysiology improves physical performance and pain cognitions 1, 4

Pharmacological Management

Treatment selection should be based on pain mechanism:

For Nociceptive Pain (e.g., osteoarthritis, musculoskeletal pain):

• Acetaminophen up to 3 g/day is the safest first-line option, particularly in patients with liver disease, heart problems, or kidney stones 5
• NSAIDs may be used cautiously but should be avoided in patients with cirrhosis (risk of GI bleeding, ascites decompensation, nephrotoxicity) and kidney stones (worsens renal function) 5

For Neuropathic Pain or Central Sensitization (e.g., fibromyalgia, neuropathy):

• Preferred agents include tricyclic antidepressants (e.g., amitriptyline), serotonin-norepinephrine reuptake inhibitors, and α2δ ligands (gabapentin, pregabalin) 2
• For amitriptyline: initiate at 10 mg three times daily with 20 mg at bedtime for elderly patients; outpatients typically start with 75 mg/day in divided doses, increased to 150 mg/day as needed 6
• Gabapentin may be considered for neuropathic components with appropriate dose adjustments based on renal function 5

Opioid Considerations:

• Reserve for moderate-to-severe pain inadequately controlled with non-opioid approaches 5
• Use extreme caution and lowest effective doses 5
• Always prescribe preventive laxative regimen to avoid constipation and potential complications 5
• For breakthrough pain in low-risk patients, use small amounts of short-acting opioids with clear agreements on quantity, frequency, and duration 1

Special Populations:

• Patients on methadone for opioid use disorder: split methadone into 6-8 hour doses for continuous pain control (strong recommendation, low quality evidence) 1
• Patients on buprenorphine: increase dosage in divided doses (4-16 mg in 8-hour intervals) as initial step; if inadequate, add long-acting potent opioid or transition to methadone maintenance 1

Interventional Procedures

Diagnostic and therapeutic interventions should be considered when conservative management fails:

• Perform interventional diagnostic procedures (selective nerve root blocks, medial branch blocks, facet joint injections, sacroiliac joint injections) with appropriate image guidance based on clinical presentation 1
• Intraarticular facet joint injections may be used for symptomatic relief of facet-mediated pain 1
• Spinal cord stimulation may be used for persistent radicular pain, CRPS, peripheral neuropathic pain, or peripheral vascular disease unresponsive to other therapies 1
• Ablative techniques should only be considered after other treatment modalities have been attempted 1

Interdisciplinary Team Approach

HIV medical providers and all chronic pain clinicians should develop and participate in interdisciplinary teams for patients with complex chronic pain, especially those with co-occurring substance use or psychiatric disorders (strong recommendation, very low quality evidence). 1

Team composition should include:

• Primary care providers and nurses 1
• Physical and occupational therapists 1
• Psychologists and psychiatrists 1
• Case managers 1
• Pain specialists for consultation when needed 1

Monitoring and Follow-Up

Establish long-term approach with periodic follow-up evaluations:

• Focus on functional goals, pain severity reduction, quality of life improvement, and treatment-related adverse events 1
• For patients with controlled chronic pain, any new pain report requires careful investigation and may necessitate treatment adjustments or dose modifications 1
• Regular assessment of liver function, renal function, and cardiac status is essential when using pharmacological treatments 5
• Monitor for signs of aberrant behavior, but maintain nonjudgmental perspective and consider "pseudo-addiction" (medication-seeking behavior due to inadequate pain control) 1

---

Common Pitfalls and Caveats

Avoid these critical errors:

• Do not focus on unproven interventions (e.g., IV vitamin/mineral infusions) as this delays implementation of evidence-based treatments 4
• Do not treat new pain in patients with existing chronic pain as simply requiring more of the current medication; new pain requires thorough reevaluation 1
• Do not persist in treating chronic pain syndrome as acute pain, as this leads to unsuccessful outcomes 7
• Do not prescribe botulinum toxin for routine care of myofascial pain (may be used as adjunct for piriformis syndrome only) 1
• Avoid NSAIDs in cirrhosis patients due to serious complications 5
• Do not neglect screening for unhealthy substance use, as this requires consultation with addiction specialists 1

Key success factors:

• Build therapeutic partnership through empathy, reflective listening, and believing patient's pain expression 1
• Set realistic expectations about treatment effectiveness and clarify that goal is functional restoration, not complete pain elimination 1
• Address modifiable psychosocial factors including self-esteem, coping skills, recent losses, mood disorders, and history of violence 1
• Document comprehensive pain assessments and treatment plans clearly in medical records 1