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Pain (Principles/MEDs/Comfort Care), Emergency Medicine

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Pain (Principles/MEDs/Comfort Care), Emergency Medicine

Basics

Description

Unpleasant sensory and emotional experience that may be secondary to actual or perceived damage to tissue, the somatosensory system, or a psychogenic dysfunction.

Incidence and Prevalence Estimates

Perform any exam and lab or radiographic studies as indicated by the patients condition.

Disposition determined by medical condition and persistence of pain.

Recurrence of pain despite adequate analgesic treatment or new unexpected pain requires a reassessment of the diagnosis and consideration of alternative causes for the pain.

  • It is an individual, subjective, multifactorial experience influenced by culture, medical history, beliefs, mood and ability to cope.

Epidemiology

  • Most common reason for seeking health care
  • Up to 78% of visits to the emergency department.
  • Pain is severe for 2/3rds of patients presenting with pain.
  • Chronic pain is present in up to 35% of the population.
  • Prevalence of neuropathic pain is 21.4% in emergency departments.

Etiology

  • Different components of pain can be combined in a same patient.
  • Nociceptive pain:Stimulation of peripheral nerve fibers (nociceptors) that arises from actual or threatened damage to non-neural tissue.Visceral pain:Stimulation of visceral nociceptorsDiffuse, difficult to locate, and often referred to a distant, usually superficial, structure.Sickening, deep, squeezing, dull.Deep somatic pain:Stimulation of nociceptors in ligaments, tendons, bones, blood vessels, fasciae, and musclesDull, aching, poorly localized pain.Superficial pain:Stimulation of nociceptors in the skin or other superficial tissue.Sharp, well defined, and clearly located.
  • Neuropathic pain:Exacerbation of normally nonpainful stimuli (allodynia).Paroxysmal episodes likened to electric shocks.Continuous sensations include burning or coldness, "pins and needles "  sensations, numbness and itching.
  • Psychogenic pain:Pain caused, increased or prolonged by mental, emotional, or behavioral factors.
  • Stimulation of peripheral nerve fibers (nociceptors) that arises from actual or threatened damage to non-neural tissue.
  • Visceral pain:Stimulation of visceral nociceptorsDiffuse, difficult to locate, and often referred to a distant, usually superficial, structure.Sickening, deep, squeezing, dull.
  • Deep somatic pain:Stimulation of nociceptors in ligaments, tendons, bones, blood vessels, fasciae, and musclesDull, aching, poorly localized pain.
  • Superficial pain:Stimulation of nociceptors in the skin or other superficial tissue.Sharp, well defined, and clearly located.
  • Stimulation of visceral nociceptors
  • Diffuse, difficult to locate, and often referred to a distant, usually superficial, structure.
  • Sickening, deep, squeezing, dull.
  • Stimulation of nociceptors in ligaments, tendons, bones, blood vessels, fasciae, and muscles
  • Dull, aching, poorly localized pain.
  • Stimulation of nociceptors in the skin or other superficial tissue.
  • Sharp, well defined, and clearly located.
  • Exacerbation of normally nonpainful stimuli (allodynia).
  • Paroxysmal episodes likened to electric shocks.
  • Continuous sensations include burning or coldness, "pins and needles "  sensations, numbness and itching.
  • Pain caused, increased or prolonged by mental, emotional, or behavioral factors.

Diagnosis

Signs and Symptoms

  • A patients self-report is the most reliable measure of pain.
  • Obtain a detailed description of pain:OnsetIf caused by an injury, determine the mechanism of injuryLocalization of painSeverity of pain:Mild pain from >0 to ≤3/10Moderate pain from >3 to <6/10Severe pain ≥6/10.Type of painDuration of painVariations of pain:Daily/weekly/monthly variationsVariations caused by physical activitiesEffect of previous analgesic drugs taken before the consult.
  • Acute vs. chronic pain:Acute pain:Transitory, usually <30 daysLasting only until the noxious stimulus is removed or the underlying damage has healedResolves quicklySubacute pain:Lasting 1 " “6 moChronic pain:Lasts more than 3 " “6 moPain that extends beyond the expected period of healing
  • Numerical Rating Scale (NRS):Patients estimate their pain intensity on a scale from 0 to 10
  • Visual Analog Scale (VAS):Patients indicate their pain by a position along a 10 cm continuous line between 2 end points, the left one representing no pain and the right one the worst pain they can imagine.
  • Clinically relevant change varies from 13 to 19 mm on a VAS or 1.3 " “1.9/10 on an NRS.
  • Faces Pain Scale:Self-report measure of pain intensity developed for children (4 " “10 yr old).
  • DN4 test:Screening tool for neuropathic painThe score ranges from 0 to 10A score of 4 or more classifies the pain as neuropathic rather than nociceptive.Pain characteristics:Burning? (Yes = 1)Painful cold (Yes = 1)Electric shocks (Yes = 1)Symptoms associated with the pain in the same area:Tingling (Yes = 1)Pins and needles (Yes = 1)Numbness (Yes = 1)Itching (Yes = 1)Decrease in touch sensation (Yes = 1)Decrease in prick sensation (Yes = 1)Can the pain be caused or increased by brushing (Yes = 1)
  • Remember to always use the same assessment tool for an individual patient.
  • Onset
  • If caused by an injury, determine the mechanism of injury
  • Localization of pain
  • Severity of pain:Mild pain from >0 to ≤3/10Moderate pain from >3 to <6/10Severe pain ≥6/10.
  • Type of pain
  • Duration of pain
  • Variations of pain:Daily/weekly/monthly variationsVariations caused by physical activities
  • Effect of previous analgesic drugs taken before the consult.
  • Mild pain from >0 to ≤3/10
  • Moderate pain from >3 to <6/10
  • Severe pain ≥6/10.
  • Daily/weekly/monthly variations
  • Variations caused by physical activities
  • Acute pain:Transitory, usually <30 daysLasting only until the noxious stimulus is removed or the underlying damage has healedResolves quickly
  • Subacute pain:Lasting 1 " “6 mo
  • Chronic pain:Lasts more than 3 " “6 moPain that extends beyond the expected period of healing
  • Transitory, usually <30 days
  • Lasting only until the noxious stimulus is removed or the underlying damage has healed
  • Resolves quickly
  • Lasting 1 " “6 mo
  • Lasts more than 3 " “6 mo
  • Pain that extends beyond the expected period of healing
  • Patients estimate their pain intensity on a scale from 0 to 10
  • Patients indicate their pain by a position along a 10 cm continuous line between 2 end points, the left one representing no pain and the right one the worst pain they can imagine.
  • Self-report measure of pain intensity developed for children (4 " “10 yr old).
  • Screening tool for neuropathic pain
  • The score ranges from 0 to 10
  • A score of 4 or more classifies the pain as neuropathic rather than nociceptive.
  • Pain characteristics:Burning? (Yes = 1)Painful cold (Yes = 1)Electric shocks (Yes = 1)
  • Symptoms associated with the pain in the same area:Tingling (Yes = 1)Pins and needles (Yes = 1)Numbness (Yes = 1)Itching (Yes = 1)Decrease in touch sensation (Yes = 1)Decrease in prick sensation (Yes = 1)Can the pain be caused or increased by brushing (Yes = 1)
  • Burning? (Yes = 1)
  • Painful cold (Yes = 1)
  • Electric shocks (Yes = 1)
  • Tingling (Yes = 1)
  • Pins and needles (Yes = 1)
  • Numbness (Yes = 1)
  • Itching (Yes = 1)
  • Decrease in touch sensation (Yes = 1)
  • Decrease in prick sensation (Yes = 1)
  • Can the pain be caused or increased by brushing (Yes = 1)
  • Observation needed to determine pain scale in nonverbal patients:Vocalization, e.g., whimpering, groaning, crying, or moaningFacial expression, e.g., looking tense, frowning, grimacing, looking frightenedAnalgesic attitudes aimed to protect a body zone in rest position (seated or lengthened)Careful movements, spontaneously or when asked.
  • All aspects of the physical exam should be gently done.
  • Posture, point tenderness, percussion tenderness, passive and active range of motion as well as active resistance.
  • It is recommended to move smoothly between the different components of the exam while warning the patient about each phase.
  • Always examine uninjured tissues first and avoid sudden movement.
  • Repeat physical exam after pain relief.
  • Vocalization, e.g., whimpering, groaning, crying, or moaning
  • Facial expression, e.g., looking tense, frowning, grimacing, looking frightened
  • Analgesic attitudes aimed to protect a body zone in rest position (seated or lengthened)
  • Careful movements, spontaneously or when asked.

Diagnosis Tests & Interpretation

Essential Workup

  • Obtain complete history of pain.
  • When a person is nonverbal and cannot self-report pain, obtain history from caregivers/other relatives/friends/neighbors.

Diagnosis Tests & Interpretation

Differential Diagnosis

  • Drug-seeking behavior in opioid dependent patients:Frequent use of emergency facilities, moving from 1 provider to another without coordinated care.Unclear history of illness, only subjective complaints (difficult to objectively verify).Patients tend to be obsessive and impatient, and request repeatedly analgesic medications.Some aspects of the physical exam should be inconsistent.Lab and radiologic studies may remain normal.
  • Frequent use of emergency facilities, moving from 1 provider to another without coordinated care.
  • Unclear history of illness, only subjective complaints (difficult to objectively verify).
  • Patients tend to be obsessive and impatient, and request repeatedly analgesic medications.
  • Some aspects of the physical exam should be inconsistent.
  • Lab and radiologic studies may remain normal.

Treatment

Pre-Hospital

  • Nonpharmacologic measures are effective in providing pain relief in a pre-hospital setting.
  • Nitrous oxide is an effective analgesic agent in pre-hospital situations.
  • Morphine, fentanyl, and tramadol can be used in a pre-hospital setting.

Initial Stabilization/Therapy

  • ABCs
  • Treat life-threatening medical/traumatic conditions as appropriate.
  • Patients with severe pain should be triaged as a priority and dispatched in a rapid care sector, ensuring rapid pain control.

Ed Treatment/Procedures

  • Nonpharmacologic measures are effective in providing pain relief and should be systematic:Immobilization of injured extremities.Elevation of injured extremities.Ice.
  • Opioids for severe pain:Preferably IV or intraosseous if IV not possibleWide interindividual variability in dose response and the delayed absorption with IM or SC routesOral opioids associated with acetaminophen represent reasonable alternatives for less severe pain:Oxycodone 5 " “10 mgHydrocodone 5 " “10 mgCodeine 30 " “60 mgTramadol 50 " “100 mg
  • Nonsteroidal anti-inflammatory drugs:Mild to moderate trauma painMusculoskeletal painRenal and biliary colicRelatively high rate of serious adverse effects including GI bleeding and nephropathy.
  • Acetaminophen provides safe and effective analgesia for mild to moderate pain with minimal adverse effects.
  • Treat associated anxiety or emotion.
  • Regional anesthesia should be considered for acute well-localized problems such as toothache, fractures, hand and foot injuries.
  • Immobilization of injured extremities.
  • Elevation of injured extremities.
  • Ice.
  • Preferably IV or intraosseous if IV not possible
  • Wide interindividual variability in dose response and the delayed absorption with IM or SC routes
  • Oral opioids associated with acetaminophen represent reasonable alternatives for less severe pain:Oxycodone 5 " “10 mgHydrocodone 5 " “10 mgCodeine 30 " “60 mgTramadol 50 " “100 mg
  • Oxycodone 5 " “10 mg
  • Hydrocodone 5 " “10 mg
  • Codeine 30 " “60 mg
  • Tramadol 50 " “100 mg
  • Mild to moderate trauma pain
  • Musculoskeletal pain
  • Renal and biliary colic
  • Relatively high rate of serious adverse effects including GI bleeding and nephropathy.

Medication

  • Acetaminophen: 500 mg (peds: 10 " “15 mg/kg, do not exceed 5 doses/24h) PO q4 " “6h, do not exceed 4 g/24h
  • Codeine: 30 " “60 mg PO q4 " “6h prn
  • Morphine:Initial bolus of 0.05 " “0.1 mg/kg IV15 " “30 mg PO q4 " “6h
  • Hydromorphone:Initial bolus 1 mg IV2 " “4 mg PO q4 " “6h
  • Oxycodone: 5 " “10 mg PO
  • Hydrocodone: 5 " “10 mg PO
  • Tramadol: 50 " “100 mg PO
  • Hydrocodone/acetaminophen: 5/500 mg PO q4 " “6h
  • Ibuprofen: 600 " “800 mg PO q6 " “8h (peds: 10 mg/kg q6h)
  • Naproxen: 250 " “500 mg PO q12h
  • Initial bolus of 0.05 " “0.1 mg/kg IV
  • 15 " “30 mg PO q4 " “6h
  • Initial bolus 1 mg IV
  • 2 " “4 mg PO q4 " “6h

Follow-Up

Disposition

  • Medical condition requiring admission.
  • Uncontrolled pain.
  • Medical condition(s) addressed
  • Pain relief defined as a final evaluation of pain ≤3/10, or a decrease of pain ≥50% from the baseline, or if the acceptable level of pain is reached for an individual patient.
  • Physicians may control pain well in the ED with IV titration, but risk poor pain control after discharge with oral opioids:Be aware of conversion rates between opioids.Be aware of conversion from IV to oral dosing.Opioids should be prescribed at fixed intervals to control pain, with additional as-needed doses as required.
  • Be aware of conversion rates between opioids.
  • Be aware of conversion from IV to oral dosing.
  • Opioids should be prescribed at fixed intervals to control pain, with additional as-needed doses as required.

Followup Recommendations

Pearls and Pitfalls

  • In case of severe pain, initiate pain relief simultaneously with the primary assessment.
  • Regular assessment of pain leads to improved pain management.
  • Nonpharmacologic measures are effective in providing pain relief and should always be considered and used when possible.
  • Titrating relatively high doses of opioid provides the best chance of delivering rapid and effective analgesia.

Additional Reading

  • Albrecht ‚ E, Taffe ‚ P, Yersin ‚ B, et al. Undertreatment of acute pain (oligoanalgesia) and medical practice variation in prehospital analgesia of adult trauma patients: A 10 yr retrospective study. Br J Anaesth. 2013;110(1):96 " “106.
  • Gueant ‚ S, Taleb ‚ A, Borel-K ƒ Όhner ‚ J, et al. Quality of pain management in the emergency department: Results of a multicentre prospective study. Eur J Anaesthesiol. 2011;28(2):97 " “105.
  • Todd ‚ KH, Ducharme ‚ J, Choiniere ‚ M, et al. Pain in the emergency department: Results of the pain and emergency medicine initiative (PEMI) multicenter study. J Pain. 2007;8(6):460-466.

Codes

ICD9

  • 338.19 Other acute pain
  • 338.29 Other chronic pain
  • 780.96 Generalized pain
  • 729.2 Neuralgia, neuritis, and radiculitis, unspecified
  • 307.80 Psychogenic pain, site unspecified
  • 729.1 Myalgia and myositis, unspecified

ICD10

  • G89.4 Chronic pain syndrome
  • G89.29 Other chronic pain
  • R52 Pain, unspecified
  • M79.2 Neuralgia and neuritis, unspecified
  • F45.41 Pain disorder exclusively related to psychological factors
  • M79.1 Myalgia

SNOMED

  • 22253000 Pain (finding)
  • 274663001 Acute pain (finding)
  • 82423001 Chronic pain (finding)
  • 247398009 neuropathic pain (finding)
  • 68962001 Muscle pain (finding)
  • 8971008 Psychalgia (finding)