Pain Disorders, Chronic

Key Features

Essentials of Diagnosis

• Chronic complaints of pain

• Symptoms frequently exceed signs

• Minimal relief with standard treatment

• History of having seen multiple clinicians

• Frequent use of several nonspecific medications

General Considerations

• Components of the syndrome

  • Anatomic changes

  • Chronic anxiety and depression

  • Anger

  • An altered lifestyle

• Importance of psychological factors increases over time

• Often involves secondary gain for the patient via financial compensation or maintaining the sick role

• Clinicians unwittingly reinforce the sick role, since the nature of medical practice is to respond to complaints of illness

• It is counterproductive for the clinician to speculate whether the patient's pain is "real"

• Acceptance of the problem must precede attempts to reduce symptoms and improve function

Clinical Findings

Symptoms and Signs

• Patients often take multiple medications, stay in bed a great deal, and experience little joy in work or play

• Typically, the anatomic problem related to the pain is irreversible

• Marked decrease in pain threshold is apparent

• Chronic anxiety and depression produce heightened irritability and overreaction to stimuli

• Patients often have a preoccupation with the body and a need for reassurance

• History of many interventions with unsatisfactory results

• Treatment failures may provoke anger, depression, and exacerbations of the chronic pain

• Relationships are impaired, including those with clinicians

• Pressure on clinicians often leads to covert rejection of the patient, such as being unavailable or making referrals to other physicians

Differential Diagnosis

• Somatic symptom disorders

• Malingering

Diagnosis

• See Essentials of Diagnosis

Treatment

Medications

• The harms of opioids generally outweigh the benefits in chronic pain management

• Analgesics and sedatives are used only on a fixed-dose schedule to reduce their conditioning effects

• Serotonin norepinephrine reuptake inhibitors (SNRIs), venlafaxine, milnacipran and duloxetine, and tricyclic antidepressants (eg, nortriptyline), in doses up to those used in depression may be helpful, particularly in neuropathic pain syndromes (Table 25–6)

• Both duloxetine and milnacipran are approved for the treatment of fibromyalgia; duloxetine is also indicated in chronic pain conditions

• Gabapentin and pregabalin can be helpful for neuropathic pain