ICD-10-CM Codes

General Information

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  Acute pain is the physiologic response and experience to noxious stimuli that can become pathologic, is normally sudden in onset, time limited, and motivates behaviors to avoid actual or potential tissue injuries (Acute Pain Medicine Shared Interest Group).

Etiology and Pathogenesis

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  Pain is multifactorial and dependent on both physiologic and psychologic components.

  
  
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  Traditional attempts to delineate acute and chronic pain, while clinically helpful, may neglect potential pathophysiologic links between the two.

  
  
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  Commonly used systems include:

  
  
  
  
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    Time course, where an upper limit of 3 to 6 months is ascribed to acute pain

    
    
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    Qualitative descriptors, where perioperative, traumatic, obstetric, etc., usually refer to acute pain processes and cancer, noncancer, neuropathic, etc., typically apply to chronic pain

  
  
  
  
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  Categorizing pain as physiologic or pathologic may be more appropriate

  
  
  
  
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    Physiologic (adaptive pain)

    
    
    
    
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      Most common type of acute pain (e.g., surgery, trauma)

      
      
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      Relies on peripheral nociceptor activation by noxious stimuli (e.g., extreme temperatures, pressure, inflammatory cytokines and chemokines)

      
      
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      Afferent pathways transmit peripheral impulses to the central nervous system

      
      
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      Efferent pathways modulate the response to noxious stimuli to locate and interpret the intensity of pain, avoid or minimize additional tissue damage, and support behavioral modifications to promote recovery and function.

    
    
    
    
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    Pathologic (maladaptive pain)

    
    
    
    
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      Less common cause of acute pain; usually associated with chronic pain (e.g., migraines, stroke, spinal cord injury)

      
      
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      Described as neuropathic pain or dysfunction of the somatosensory system

    
    

  
  
  
  
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  The pain experience is significantly impacted by anxiety, depression, pain catastrophizing, fear avoidance, previous experience with pain, culture, and beliefs.

History and Physical

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  A thorough history is essential, given the subjective and individualized nature of pain.

  
  
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  The simple mnemonic, OLD CARTS, covers most components of a pain history (Onset, Location/radiation, Duration, Character, Aggravating factors, Relieving factors, Temporal association, Severity).

  
  
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  It is additionally helpful to ascertain associated symptoms (e.g., nausea and vomiting), effect on activities and sleep, relevant medical history, previous and current treatments, and factors influencing the patient’s response to treatment (e.g., beliefs, knowledge, and expectations of pain and its management).

  
  
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  Physical examination becomes more important when history is limited by critical illness, age, communication barriers, or cognitive impairment.

  
  
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  Provocative maneuvers such as Spurling test, Tinel sign, Phalen test, straight leg raise, and slump test may reveal less apparent neurogenic involvement.

  
  
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  Findings suggestive of pain include increased respiratory rate, heart rate, blood pressure, palmar sweating, intracranial pressure, and agitation.