Pain management

Pain is an unpleasant sensation (sensory and emotional) with biological, psychological, and social components. There are a number of ways to differentiate between types of pain, the most common of which is the distinction between acute and chronic pain. Acute pain lasts for < 1 month. It can indicate actual or potential tissue damage and is associated with trauma, surgery, and illness. Subacute pain lasts for 1–3 months and chronic pain is generally defined as pain lasting > 3 months (normal tissue healing time). Standardized pain intensity scales are used to evaluate pain in a clinical setting. Pain management uses a multimodal approach, which may include the use of pharmacological therapy, physical therapy, behavioral therapy, and/or interventional or surgical methods. Acute pain requires prompt treatment. Analgesics should be tailored to the inciting cause; the WHO analgesic ladder can be used to help structure pain relief strategies. The management of chronic pain can be challenging; initial management involves nonpharmacological therapy (e.g., physical therapy, cognitive behavioral therapy), nonopioid analgesia, and consideration of interventional pain management. For chronic pain refractory to nonopioid management, opioid therapy may be considered only if benefits outweigh risks. Patients who are prescribed opioid therapy for chronic pain should undergo close monitoring, and the risks versus benefits of treatment should be regularly reassessed; opioids should be tapered or discontinued if the benefits no longer outweigh the risks. For information on psychogenic pain, see “Somatic symptom and related disorders.”

By duration

• Acute pain
  • A warning signal indicating actual or potential tissue damage that triggers a protective reaction
  • Typically associated with trauma, surgery, and acute illness
  • Lasts < 1 month ^[1]
• Subacute pain: lasts 1–3 months ^[1]
• Chronic pain
  • Pain that lasts beyond the normal tissue healing time (> 3 months) ^[1][2]
  • Unlike acute pain, chronic pain has no protective role in preventing further tissue damage and can be considered a disease entity in its own right.

By type

• Nociceptive pain: pain that is triggered by chemical, mechanical, or thermal stimuli (noxious stimuli)
  • Somatic pain (musculoskeletal pain): localized, sharp pain that varies in duration and quality (Aδ fibers)
  • Visceral pain: dull, diffuse, deep pain (C fibers)
• Neuropathic pain: pain caused by abnormal neural activity that arises secondary to injury, disease, or dysfunction of the nervous system
  • Central pain: caused by CNS dysfunction; (e.g., from lesions produced by an ischemic stroke, phantom limb pain)
  • Peripheral pain: caused by damage to peripheral nerves; (e.g., diabetic neuropathy, postherpetic neuralgia)
  • Sympathetically mediated pain: caused by damage to autonomic nerves (e.g., complex regional pain syndrome)
• For an overview of pain symptoms in patients with serious or life-threatening illnesses, see “Pain concepts in palliative care.”

• Pain pathway: nociceptors detect a chemical, mechanical, or thermal noxious stimulus → conversion of stimulus to an electric signal (action potential): → C fibers and Aδ fibers carry afferent input to the dorsal horn of the spinal cord → secondary nociceptive neurons in the spinothalamic tract carry afferent input to the thalamus in the CNS → pain perception and a response sent along efferent pathways, which results in pain modulation and/or a reaction ^[3]
• Withdrawal reflex: a polysynaptic spinal reflex that causes a part of the body to move away from a painful stimulus (e.g., a hot object) via contraction of flexor muscles and relaxation of extensor muscles ^[3]

Pain sensitization ^[4][5]

• Abnormal pain perception due to increased neuronal sensitivity to noxious stimuli (hyperalgesia) and/or reduced neuronal threshold to otherwise normal stimuli (allodynia) in response to local injury, inflammation, and/or repetitive stimulation
• Plays a major role in the generation and maintenance of chronic pain and neuropathic pain (e.g., postherpetic neuralgia)
• Although not completely understood, the pathophysiology is thought to involve the following two mechanisms:
  • Peripheral sensitization
    • Injury, inflammation, or repetitive stimulation of the peripheral nociceptive neurons → local release of chemical mediators (e.g., cytokines, nerve growth factors, histamine)→ repeated or prolonged exposure to chemical mediators upregulates the ion channels in the nociceptors → increases sensitivity and/or reduces threshold to chemical mediators even further → increased action potentials → abnormal pain perception
    • Usually ceases once the tissue injury or inflammation heals
  • Central sensitization
    • Injury and/or inflammation of the CNS (e.g., dorsal horn of the spinal cord, brain) → increased excitability and reduced inhibition in the CNS and recruitment of non-nociceptive fibers (e.g., Aβ fibers) into the nociceptive pathway → abnormal pain perception
    • Chronic peripheral pain disorders can be a significant driver to the sensitization of central nociceptive neurons
    • Usually continues even after the initial injury has healed

Referred pain

• Definition: pain that is perceived at a location other than that of the causative stimulus; projection of pain usually onto a specific dermatome or myotome of the corresponding segment of the spinal cord
• Common examples of referred pain
  • Right shoulder pain in patients with cholecystitis or perforated PUD
  • Kehr sign: left shoulder pain associated with diaphragmatic irritation resulting from hemoperitoneum (classically secondary to splenic rupture)
  • Left-sided chest and arm pain: myocardial infarction
  • Periumbilical pain in the early stages of appendicitis
• Treatment: Select treatments may reverse this pathway.

References:^[6][7][7][8]

Phantom limb syndrome

• Definition
  • Phantom sensation: is a sensation that the amputated limb is still partially or totally existent
  • Phantom pain: sensation of pain in an amputated limb
    • Intermittent pain of varying character (e.g., burning, tingling, shooting, itching, squeezing, aching, electric shock-like sensation)
    • Onset usually within days to weeks after amputation; pain often resolves or lessens over time
• Incidence: common complication after upper or lower extremity amputation
• Pathophysiology: primary somatosensory cortex neurons that formerly respond to signals from the amputated limb respond to signals from adjacent neurons that carry sensation from other parts of the body → functional reorganization of the somatosensory cortex ^[9]
• Diagnosis: diagnosed only after exclusion of other causes of stump pain (e.g., infection, ischemia, post-surgical neuroma)
• Treatment: multimodal approach
  • Mirror therapy
  • Transcutaneous electrical nerve stimulation: an analgesic therapy used to modify pain perception by administering continuous electrical impulses via electrodes on the skin
  • NMDA receptor antagonists
  • Adjuvant therapy (e.g., tricyclic antidepressants, anticonvulsants)
• Prophylaxis: perioperative regional anesthesia

References:^[10]

To optimize pain management, a thorough history and assessment of pain is required prior to initiating treatment.

• Pain characteristics (location, quality, temporal aspects, triggers)
• Associated symptoms (changes in mobility and strength)
• Previous pain assessments and/or treatment
• Pain intensity scale: subjective grading of pain severity by the patient
  • Numeric rating scale (NRS): most common pain scale, evaluates pain on a scale from 0–10
  • Visual analog scale (VAS): visual equivalents suitable for children
  • Verbal descriptor scale
• Impact of pain
  • E.g., on daily life, sleep, activities
  • This may also be evaluated through the use of validated scales, e.g., the PEG pain scale for chronic pain
• Pain diary: regular documentation of the pain intensity to identify peaks and triggers; enables treatment optimization

Pain can be difficult to assess in nonverbal patients; obtain supporting information from caretakers and use a specialized pain score, e.g., the nonverbal pain scale.

Be aware of implicit bias in the assessment of pain: Hispanic and Black patients are less likely to receive any and/or appropriate analgesia compared to White patients, even when reported pain scores are identical. ^[11][12]

Pain is subjective! Pain scales are used to assess a patient's pain and response to pain management over time. They cannot be used to compare pain intensity between patients.

References:^[13]

WHO analgesic ladder

The WHO analgesic ladder is a 3-step algorithm for the management of acute and chronic pain.

• Regular analgesic (modified-release drugs, administered at fixed times and doses)
  • By the mouth: preferably, analgesics should be given orally.
  • By the clock: regular administration at fixed times, rather than on demand
  • By the ladder (symptom-oriented): if the patient is still in pain, it is necessary to go up a step
• Appropriate PRN medication
  • Short-acting analgesics for peaks in pain
  • If PRN medication is required ≥ 3×/day → inadequate analgesia likely; review the regular medication
• Additionally, concurrent treatment with adjuvant drugs

Nonopioid analgesics are first-line agents for pain; prescribe them alone for mild to moderate pain and in combination with opioids for severe pain. ^[15]

For both opioid and nonopioid analgesics, use the minimal effective dose for the shortest duration of time to minimize adverse effects. Pain intensity scales should be used in regular intervals to assess the success of pain management.

Oral analgesics

All patients being discharged with opioid medications should receive counseling on the use of prescription opioids.

Parenteral analgesics

Analgesic suppositories

• Acetaminophen
• Indomethacin
• Aspirin

Topical analgesics

Adjuvant analgesics

Anticonvulsants

Anticonvulsants are useful adjuncts in the management of neuropathic pain. They typically will not be helpful for acute pain, rather are more commonly used for chronic neuropathic pain.

• Gabapentin
• Pregabalin
• Carbamazepine

Muscle relaxants

Consider muscle relaxants in patients with pain associated with muscle spasticity.

• Cyclobenzaprine
• Methocarbamol
• Baclofen

Antidepressants

Tricyclic antidepressants and SNRIs can be helpful for chronic pain syndromes and neuropathic pain. Antidepressants for chronic or neuropathic pain are recommended by the American Society of Anesthesiologists in their 2010 guideline, but only duloxetine is FDA-approved for this indication. All others are off-label use. ^[25][26]

• Tricyclic antidepressants
  • Amitriptyline ^[27]
  • Doxepin
  • Clomipramine
• SNRIs
  • Duloxetine
  • Venlafaxine

Intravenous patient-controlled analgesia

• Infusion pump designed to release additional IV medication in response to patient's request
• Indication: severe acute pain that is difficult to manage and is expected to be limited in duration

Management of side effects of analgesics

• Laxatives (see constipation)
• Antiemetics
• Proton-pump inhibitors (PPIs): Consider in patients taking frequent NSAIDs.

Condition-specific analgesia

• Some conditions require specific pain management.
• Optimizing the management of underlying conditions may also reduce the need for analgesia.
• See:
  • Acute pain in sickle cell disease
  • Prophylactic therapy of migraine
  • Treatment of diabetic peripheral neuropathy
  • Treatment of osteoarthritis of the hip and knee
  • Treatment of fibromyalgia
• For pain related to cancer or other high-morbidity illnesses (e.g., chronic pain related to sickle cell disease), see “Pain management in palliative care.” ^[1]

Multiple nonpharmacological therapies are often used in combination (e.g., exercise therapy and cognitive behavioral therapy).

Physical modalities ^[1][28]

Consider referral to physical therapy and/or occupational therapy.

• Massage
• Thermotherapy (e.g., focused ultrasound ) ^[29]
• Desensitization techniques ^[30]
• Regular exercise (e.g. walking) and exercise therapy for chronic pain ^[1][31]

Patients may require analgesia to participate in physical therapy; maximize nonopioid pharmacological therapy first. ^[32][33]

Psychological modalities ^[1][28]

Refer to a psychologist as needed.

• Relaxation techniques ^[1]
  • Biofeedback training
  • Progressive muscle relaxation
  • Mindfulness
• Cognitive behavioral therapy
• Hypnosis ^[34][35]

Other modalities ^[1][28]

• Complementary and alternative medicine
  • Acupuncture ^[1][36]
  • Osteopathic manipulative treatment (e.g., spinal manipulation for low back pain and tension headache)
  • Mind-body techniques (e.g., yoga, tai chi)
• Neuromodulation and nerve ablation techniques ^[1][28]

Approach ^[37]

• Provide prompt analgesia for severe acute pain.
• Assess pain severity with a pain intensity scale.
• Document recent analgesic use (e.g., type and dosage).
• Tailor the treatment strategy to the patient, the underlying condition, and the care setting.
  • Use the WHO analgesic ladder as a guiding principle.
  • Maximize nonpharmacological an nonopioid analgesia whenever possible. ^[1]
  • See “Choice of analgesic for acute pain” for cases in which opioids are required.
• For specific dosages, see “Oral analgesics,” “Parenteral analgesics,” and “Adjuvant analgesics.”

Choice of analgesic for acute pain ^[1]

Administer acute pain management promptly; withholding it does not improve the accuracy of a physical examination. ^[37]

Only prescribe opioids if the benefits outweigh the risks. ^[1]

• Risk mitigation: See “Risk mitigation for opioid prescribing.”
• Prescribing principles
  • Use immediate-release opioids rather than extended-release or long-acting opioids.
  • Start at the lowest effective dose.
  • Prescribe PRN doses rather than scheduled doses.
  • Limit prescription duration to the expected duration of severe pain.
  • Reevaluate the risk-benefit ratio if dosage increases are required. ^[1]
  • See “Oral analgesics” and “Parenteral analgesics” for dosages.
  • For management of overdose, see “Opioid overdose.”

Management of acute-on-chronic pain requires significant empathy and skill.

General principles ^[37]

Follow local departmental policies if available.

• Establish treatment goals.
  • The goal of treating the acute episode is to allow the patient to return to baseline function.
  • Complete alleviation of pain is typically not possible.
• Obtain detailed pain assessment and review existing care plans.
• Consult the clinical provider in charge of long-term pain management whenever possible.
• Identify and treat reversible causes of pain, e.g., a new:
  • Comorbid condition (e.g., renal colic in patients with chronic back pain)
  • Episode of a recurrent condition (e.g., vasoocclusive crisis in patients with sickle cell disease)
  • Condition that affects pain medication metabolization (e.g., malabsorption)
• Consider systemic barriers to accessing treatment.
• Consider admission for individual management of patients with progression of terminal illnesses if no reversible cause is identified.

Acute-on-chronic pain management in hospital-based settings ^[1][37]

• For patients already on an opioid regimen who have uncontrolled pain:
  • Preferentially add nonopioid analgesics (e.g., NSAIDs, acetaminophen, adjuvant analgesics).
  • If additional opioids are required, match duration to that of the expected superimposed severe pain.
• Individualized therapy is recommended for patients with sickle cell disease, cancer, and palliative care and/or end-of-life care needs. ^[1]

Involve the patient's regular health provider in treatment decisions whenever possible and be aware of the potential for drug diversion of prescriptions made by other health providers.

• Severe pain
  • Follow approach to acute pain for choice of analgesic. ^[37]
  • For specific dosages, see “Oral analgesics,” “Parenteral analgesics,” and “Adjuvant analgesics.”
  • Reassess pain severity every hour or more frequently if necessary.
  • For emergency procedures, consider analgesics for procedural sedation.
  • Consider a subanesthetic ketamine infusion as a stand-alone treatment or an adjunct to opioids. ^[38]
• Extremity injuries
  • Administer ice, elevation, and immobilization as indicated.
  • Offer initial parenteral analgesics for pain caused by an acute deformity (e.g., fracture, dislocation) that is unresponsive to immobilization.
  • Consider local anesthesia or regional anesthesia for localized pain.
• Minimize undertreatment ^[37]
  • ED patients' pain can be undertreated for a variety of reasons, e.g., communication barriers, atypical presentations, and implicit biases.
  • Patients at risk of undertreatment include children, individuals of different cultural and/or linguistic backgrounds, and individuals with neurocognitive disorders.
• Ambulatory opioid prescriptions
  • Limit duration to < 3–5 days.
  • Arrange rapid follow-up with a regular health provider for dosage adjustments.
  • See also “Opioids for acute pain.”
• Acute-on-chronic pain: See “Acute-on-chronic pain management in hospital-based settings.”

Approach ^[1][28][39]

This content applies to the management of chronic and subacute pain unrelated to cancer, sickle cell disease, or other high-morbidity illnesses. For pain related to those conditions, see “Pain management in palliative care.” Acute pain management and acute-on-chronic pain management are detailed separately.

• Perform an initial assessment.
• Optimize the following as needed:
  • Management of comorbid mental health conditions ^[1][40]
  • Condition-specific pain management
• Provide patient education on chronic pain management. ^[41]
• Consider enrolling patients into a pain management program (PMP). ^[41][42][43]
• According to the WHO analgesic ladder approach, initiate nonopioid management of chronic pain. ^[44][45]
• Periodically reevaluate treatment efficacy using a validated tool to assess pain and functioning (e.g, the PEG pain scale).
• For refractory pain, consider initiation of opioid therapy only if benefits outweigh risks.
  • Establish goals of treatment and an opioid exit strategy before initiation.
  • Continue nonopioid therapies in conjunction with opioid therapy.
  • Do not rapidly taper or abruptly discontinue opioid therapy once started.

A biopsychosocial model of medical care is integral to chronic noncancer pain management. ^[28]

Use palliative pain management for pain related to cancer, sickle cell disease, or other high-morbidity illnesses. ^[1]

Avoid perpetuating existing racial and ethnic disparities in chronic pain management. ^[1]

• Obtain a complete history and perform a physical exam, including:
  • Evaluation of pain and functioning, ideally with a validated scale such as the PEG pain scale ^[39]
  • Assessment of social determinants of health, psychosocial well-being, and other potentially contributory factors ^[35]
• Perform a medication review.
• Consider imaging and further studies as needed to: ^[1][41][46]
  • Exclude serious pathology (e.g., for patients with neurological deficit). ^[1]
  • Identify conditions requiring specific management (e.g., joint replacement for severe hip osteoarthritis).

Refer patients with these indications to a pain management specialist: ^[1]

• Age < 18 years ^[47]
• Pregnant individuals ^[48]
• Complex regional pain syndrome
• History of substance use disorder
• High morphine milligram equivalent (MME) prescription required ^[1]
• Refractory or severe pain
• Need for interventional pain management

Individuals without indications for referral to pain management can typically be managed by a primary care clinician.

• Ensure patients understand the diagnosis and how to manage their condition; see “Managing chronic conditions.”
• Provide pain neuroscience education. ^[41][49]
• Manage the patient's expectations, e.g., explain that: ^[1]
  • It can take weeks to months for pain to improve in response to treatment.
  • Goals should be realistic, e.g., pain reduction (not elimination) and improvement in function.
  • Chronic pain is managed in a stepwise manner.
• Educate patients on when to take medication for pain management.
• Support patients in developing a self-management approach. ^[41][50]

A combination of multimodal nonpharmacological analgesia and various types of nonopioid pharmacotherapy for chronic noncancer pain may be used. To select the appropriate pharmacotherapy: ^[1]

• Assess for contraindications.
  • Evaluate for hepatic and/or renal impairment.
  • Determine the nature of any reported adverse effects of previous therapy.
  • Consider pharmacology in older adults to minimize adverse effects.
• Determine the type and frequency of the pain (for dosages, see “Treatment of pain”).
  • Daily pain: Consider regularly scheduled nonopioid oral analgesia.
  • Breakthrough pain: Consider as-needed nonopioid oral analgesia.
  • Neuropathic pain: Consider regular adjuvant analgesics (e.g., anticonvulsants, antidepressants) or topical lidocaine or capsaicin.
  • Joint pain: Consider intraarticular glucocorticoid injection.
  • Radiculopathy: Consider epidural glucocorticoid injection.

There is insufficient evidence to support the use of cannabis or cannabinoids for chronic pain management; if being considered, check local laws before prescribing. ^[1][51]

Decision to initiate ^[1][32][43]

• Perform a thorough evaluation of chronic noncancer pain.
• Ensure nonopioid therapy for chronic noncancer pain has been maximized and alternative treatment options have been trialed.
• Check institutional and state guidelines for indications for opioid prescribing. ^[43]
• Determine if the patient has contraindications to opioids or risk factors for opioid-related harm.
• Discuss benefits and risks of opioid therapy with patient; ensure benefits outweigh risks, given type of pain and goals of treatment. ^[1]
  • Benefits: possible minor reduction in pain ^[1]
  • Risks
    • Adverse effects of opioids, including the development of opioid use disorder
    • Pain may worsen because of opioid-induced hyperalgesia.
    • May impact employment opportunities, especially in safety-critical jobs ^[1]
• If an opioid prescription is deemed appropriate, follow risk mitigation practices.

Ensure patients are aware that chronic use of opioids can interfere with employment opportunities, especially in safety-critical jobs. ^[1]

Before initiating opioid therapy, take a full patient history, screen for comorbid mental health conditions, and perform medication reconciliation to determine patient suitability for opioid therapy and to reduce modifiable risk factors.

Risk mitigation ^[1][43]

Consider risk mitigation for opioid prescribing prior to starting opioids and at each follow-up appointment.

• Assess for the development of contraindications to opioids or risk factors for opioid-related harm.
• Review:
  • State and federal laws relevant to prescribing controlled substances
  • The state's prescription drug monitoring program (PDMP)
  • Principles of prescribing for older adults, if relevant
• Prescribe naloxone and provide education on its use if any of the following are present: ^[52]
  • State requires coprescription
  • Risk factors for opioid overdose in patient or household members
  • Sleep-disordered breathing
• Provide counseling on the use of prescription opioids.
• Consider referral to a pain specialist and/or the use of buprenorphine for pain management in patients who: ^[53]
  • Require long-term daily opioids
  • Are unable to taper or discontinue opioids
  • Are at risk of opioid use disorder or have a history of opioid use disorder
• Avoid concurrent use of opioids and sedative-hypnotic medications (e.g., benzodiazepines, sleeping aids; , muscle relaxants) or prescribe with extreme care.

Ensure patients with risk factors for opioid overdose have been provided with naloxone and educated on how to use it. ^[1]

The prescription of more than a 90-day supply of opioids is associated with a dose-dependent increase in the risk of adverse effects of opioid use, including opioid use disorder. ^[1]

Aberrant drug-related behaviors

Aberrant drug-related behaviors may suggest abuse, misuse, or diversion of opioids.

• Concerning behaviors include: ^[54][55].
  • Obtaining medication from nonmedical sources
  • Requesting prescriptions early
  • Frequently reporting loss of prescriptions
  • Missing or canceling appointments at which no opioid refill is anticipated
  • Obtaining prescriptions from multiple providers
  • Presenting to the emergency department for medications
• Managing patients with aberrant drug-related behaviors
  • Do not discharge patients from care unless they are violent or threatening. ^[1][56]
  • Evaluate for opioid use disorder and/or other substance use disorders; if present, provide treatment with a multidisciplinary team.

Urine drug monitoring for opioid therapy ^[57][58]

• Consider urine toxicology prior to starting opioid therapy and at least annually thereafter. ^[1][57]
• Communicate clearly with patients to reduce misunderstandings.
  • Explain urine drug monitoring procedures; and their purpose in maintaining patient safety.
  • Ask nonjudgmentally about the nature and timing of all recent substance use before ordering a test.
• Interpret results with care.
  • Screening immunoassays have limitations; ask patients nonjudgmentally about any unexpected results. ^[1][57][58]
  • If results are unexplained and/or will affect management, obtain confirmatory testing. ^[1][57]
  • Do not use results punitively (e.g., discontinuation of opioids, discharge from practice).

Initiation ^[1][39][43]

• Establish the following, using shared decision-making.
  • How and when treatment efficacy will be assessed: Patients should experience functional gains as measured, e.g., with the PEG pain scale. ^[32]
  • An opioid exit strategy: how opioids will be discontinued or how to transition to medication-assisted treatment if the risks outweigh the benefits
• Create a controlled substance agreement and ensure informed consent has been obtained in the appropriate form. ^[43]
• Provide anticipatory guidance to avoid adverse effects of opioid use.
• Establish dosing and frequency based on the pharmacology of opioids (see “Treatment of pain” for specific dosages).
  • Use short-acting rather than long-acting formulations.
  • Start with a low dose and titrate to the lowest effective dose. ^[1]
• In patients with hepatic or renal impairment, consider longer dosing intervals.
• Prescribe as needed rather than scheduling doses. ^[1]
• Create a plan for events requiring acute-on-chronic pain management.
• Follow-up within 1–4 weeks after initiating therapy to evaluate for improved functioning and pain control. ^[1]

Ongoing therapy ^[1][43]

• Follow-up:
  • At least every 3 months to evaluate efficacy and safety ^[1]
  • More frequently for patients with a high risk of overdose or misuse ^[1]
• Continue to:
  • Maximize nonopioid management of chronic noncancer pain.
  • Follow risk mitigation for opioid prescribing at every visit, including consideration of urine drug monitoring for opioid therapy at least annually.
• Maintain accurate records at every visit, including:
  • Calculated daily MME
  • Average daily pain level
  • Functional assessment (e.g., ability to perform ADLs, score on PEG pain scale)
  • Adverse effects
  • Aberrant drug-related behaviors
  • Confirmation of review of the state's PDMP ^[1]
• Convert from immediate-release to extended-release opioids only if:
  • Pain is ongoing, severe, and constant
  • Patient has opioid tolerance (when relevant) ^[59]
• If transitioning from one formulation to another, reduce the MME of the new formulation initially.

There is a paucity of evidence supporting > 12 months of opioid therapy for chronic pain management. ^[1][32]

Prescriptions ≥ 50 MME/day are unlikely to improve pain and also increase the risk of adverse effects of opioids. ^[1]

Tapering

The decision to taper chronic opioid therapy (and, possibly, to discontinue therapy) should be made on an individual basis using shared decision-making, weighing up the benefits and risks of opioid therapy. ^[1][43]

The goal of tapering may be complete discontinuation or dose reduction to improve the risk versus benefit profile. ^[1]

Indications ^[1][32]

Consider tapering in the following scenarios:

• Patient request
• Resolution of pain
• Lack of response to therapy, e.g.:
  • Inadequate improvement in quality of life, function, or pain scores
  • Escalation of dosages without improvement
• Adverse effects of opioids impacting quality of life
• Evidence of diversion of prescription drugs or misuse (aberrant drug-related behaviors)
• Overdose event or concern for impending overdose ^[1]
• Risk factors for opioid-related harm

Consult a pain specialist if considering tapering opioids in pregnant individuals. ^[1]

Process ^[1][43]

• Use a multidisciplinary approach.
• Avoid rapid tapering and sudden discontinuation.
• Advise patients that pain may worsen initially.
• First, reduce the dose per administration.
  • Maximize nonopioid therapy for chronic noncancer pain.
  • Determine tapering speed based on duration of opioid use: ^[1]
    • < 1 year: Taper at ≤ 10% of the original dose per week.
    • ≥ 1 year: Taper at ≤ 10% of the original dose per month.
  • Slow the taper if signs of withdrawal develop.
• Once the lowest dose per administration has been achieved:
  • Gradually increase the dosing interval.
  • Discontinue opioids when the interval is less than once daily.
• Follow-up monthly during tapering
  • Consider the patient's wishes to slow or pause the taper.
  • Evaluate for and manage complications of opioid tapering

Do not rapidly taper or discontinue opioids unless the patient is at imminent risk for life-threatening complications such as overdose. ^[1]

Inform patients that they are at increased risk for overdose during and shortly after tapering because of decreased tolerance. ^[1]

Most patients on long-term opioid therapy who agree to taper or discontinue opioids experience overall satisfaction, with improved quality of life and no increase in pain, but may experience short-term effects of hyperalgesia, insomnia, and agitation. ^[1]

Management of complications ^[1]

• Development of opioid withdrawal symptoms
  • Slow or pause the taper.
  • Consider medications for opioid withdrawal.
• Inability to taper or discontinue because of ongoing pain
  • Maximize nonopioid therapies for chronic noncancer pain
  • Consider referral to a pain specialist and/or the use of buprenorphine for pain management.
• Unmasking of opioid use disorder: See “Treatment of opioid use disorder.”
• Development or unmasking of depression and/or anxiety
  • See “Major depressive disorder” and “Anxiety disorders.”
  • Involve mental health professionals in care as needed.
• Overdose due to decreased tolerance: Prescribe naloxone. ^[52]
• Development of aberrant drug-related behaviors: Engage multidisciplinary team care and address any underlying substance use disorders.

Pain in critically ill patients

Assessment of pain in the ICU

• Patients in ICU are typically unable to communicate and require a specialized pain scale ^[60]
• Behavioral pain scale
  • Used to identify pain in critically ill patients on mechanical ventilation
  • Three items are evaluated and awarded points: facial expression, movement of the upper limbs, and mechanical ventilation compliance.
  • ≥ 5 points indicates significant pain
• Critical care pain observation tool (CCPOT)
  • Used to identify pain in critically ill patients.
  • Four items are evaluated and awarded points: facial expressions, body movements, ventilator compliance in intubated patients or vocalization in nonintubated patients, and muscle tension
  • ≥ 3 points indicates significant pain
• For subjective grading of pain severity by the patient, see “Pain intensity scale”

Pain management ^[61]

• Preemptive analgesia for extubation and invasive procedures
• Multimodal analgesia depending on the severity and type of pain
  • Lowest effective dose IV opioids (first-line)
  • Adjuvant NSAIDs
  • Gabapentin or carbamazepine; in case of neuropathic pain
• Consider using continuous infusions or regular doses of analgesics
• Regular assessment of the severity of pain and response to analgesia

Be aware of the adverse effects of opioids (e.g., delirium, CNS depression, tolerance) or NSAID therapy!

Pain in neonates and infants

• Background ^[62]
  • Pain pathways are developed by the 20^th week of gestation.
  • Newborn and preterm infants are sensitive to pain and stress.
  • Procedural pain
    • Pain and stress that occur as a result of medical procedures, e.g., IV cannulation, venipuncture, finger prick, heel lance, lumbar puncture, bone marrow aspiration
    • Common in pediatric ICU patients, preterm neonates, children with malignancy
  • Nociceptive stimuli induce behavioral, autonomic, and hormonal responses in infants similar to those seen in older individuals.
  • Chronic or recurrent exposure to nociceptive stimuli can result in sensitization of the maturing neuronal pathways → hypersensitivity to pain
• Clinical features
  • Facial grimacing
  • Crying
  • Changes in crying pattern
  • Inconsolableness
  • Irritability
  • Changes in sleep pattern
• Neonatal pain assessment
  • Scoring systems for acute and postoperative pain in infants evaluate physiological parameters , behavioral changes , and/or contextual factors.
  • Examples: premature infant pain profile (PIPP), neonatal infant pain scale (NIPS), neonatal pain agitation sedation scale (N-PASS), crying, requires oxygen saturation, increased vital signs, expression, sleeplessness (CRIES) score
• Management: neonatal pain ladder ^[62][63]
  • Principles
    • Appropriate analgesia according to the stages of the WHO analgesic ladder
    • Preemptive analgesia for painful procedures administered before, during, and after the procedure
    • Regular assessment of the severity of pain and response to analgesia
    • The choice of the step depends on the anticipated intensity of pain
    • Steps can be combined if single measures are insufficient.
  • Analgesic steps
    • Step 1: nonpharmacological measures, e.g., breastfeeding, use of a pacifier, skin-to-skin contact, oral sucrose
    • Step 2: topical analgesia (e.g., topical lidocaine, tetracaine gel)
    • Step 3: oral, rectal, or IV administration of acetaminophen or NSAIDs
    • Step 4: IV infusion of opioids
    • Step 5: subcutaneous infiltration of lidocaine or specific nerve blocks
    • Step 6: sedation or general anesthesia

• One-Minute Telegram 61-2022-2/3: Pain control after arthroscopy: Just say no to (more) narcotics!

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