Module 9.1 - Pain Flashcards
What is acute pain?
- Duration is short- usually < 6 months
- Treatment is definitive due to clear source of injury (i.e. surgery)
- Generally resolves on its own as healing process occurs
What is chronic pain?
- Usually > 6 months duration,
- Rarely resolves on its own
- Examples: RA, OA, post-herpetic neuralgia, diabetic neuropathy, back pain
What is somatic pain?
Pain that arises from bone, muscle, joint, skin, connective tissue; tends to be throbbing or aching in nature and well-localized
What is visceral pain?
Pain that arises from the visceral organs, i.e. GI tract, pancreas or liver; tumor involvement or pain in hollow organ; may be vague and often dull in nature.
What is neuropathic pain?
- Results from abnormal processing by the peripheral and central nervous systems; can be from disease (such as DM) affecting the somatosensory system
- Characterized by unusual burning, tingling sensations, electric shock-like quality to pain and may be triggered by a very light touch
What are the 2 types of neuropathic pain?
- Centrally generated pain: involving the dysregulation of the peripheral, central or autonomic nervous system (phantom limb pain, burning pain below spinal cord lesion)
- Peripherally generated pain: involving pain along the distribution of nerves, or an injury to the peripheral nerves (diabetic neuropathy, post-herpetic neuralgia, trigeminal neuralgia or nerve entrapment)
What are some adverse physiologic and psychological consequences associated with acute pain?
- Reduced tidal volume
- Excessive stress response
- Progression to chronic pain
- Inability to comply with rehabilitation
- Patient suffering and dissatisfaction
- Acute pain is more difficult to manage if permitted to become severe in nature
What are the treatment goals for chronic pain?
- Chronic pain is often debilitating and associated with significant physical, emotional and social issues.
- Treatment should address social and psychological consequences of pain as well as any physical pathology
- Assessment should include the patient’s acceptance of their condition, their motivation to participate in treatment and the ability to follow-through with recommendations; as well as, available time and resources
Main goals:
- Diminished suffering including pain and associated emotional distress
- Restore or increase physical, social and recreational function
- Optimize health and well-being
- Improve coping ability
How do you manage patients with chronic pain?
1. Use a multi-modal therapy approach:
- Medications from different classes (combination drug therapy)
- Rehabilitative therapies: physical therapy, occupational therapy
- Regional anesthesia: nerve blockade
- Interventional pain management: trigger point or steroid injections
2. Medical Management
- Differs from acute pain management in that in chronic pain management there is greater use of adjuvant analgesics
- Chronic pain reflects a greater frequency of neuropathic pain that has a reduced responsiveness to traditional analgesics
- EBP recommendations: Clinical trials support the use of anti-depressants, antiepileptic medications (Gabapentin) and local anesthetics as first line approaches to the treatment of chronic pain.
3. Non-Pharmacological Management
- Reconditioning (physical therapy/occupational therapy) reduces pain and promotes physical and psychological rehabilitation; thereby empowering the patients
- Biofeedback and relaxation can relax muscles and reduce autonomic nervous arousal.
How do you treat patients with chronic arthritis pain? What non-opioids, opioids, or adjuvant analgesics would you use?
Non-opioids:
- Acetaminophen, NSAIDs, Selective COX-2 inhibitors
Opioids:
- Short term mild opioids for flare-ups
Adjuvant Analgesics:
- Corticosteroids (oral for RA, injections for OA and RA); topical capsaicin and diclofenac and lidocaine patches
How do you treat patients with chronic lower back pain? What non-opioids, opioids, or adjuvant analgesics would you use?
Non-opioids:
- Acetaminophen, NSAIDs, Selective COX-2 inhibitors
Opioids:
- Short term opioids for mild to moderate flare-ups
Adjuvant Analgesics:
- Muscle relaxants (short term)
- Topical anesthetics: lidocaine patches, capsaicin
How do you treat patients with chronic fibromyalgia? What non-opioids, opioids, or adjuvant analgesics would you use?
Non-opioids:
- Acetaminophen, NSAIDs, Selective COX-2 inhibitors
- Pregabalin (Lyrica) - works to reduce electrical activity a/w overactive nerve impulses
Opioids:
- Short term opioids for mild to moderate flare-ups
- Tramadol
Adjuvant Analgesics:
- Muscle relaxants (short term)
- Tricyclic antidepressants: amitriptyline and imipramine
- Second generation antidepressants: Duloxetine, fluoxetine, etc.
How do you treat patients with chronic peripheral neuropathy? What non-opioids, opioids, or adjuvant analgesics would you use?
Non-opioids:
- Acetaminophen, NSAIDs
Opioids:
- Short term
Adjuvant Analgesics:
- Anti-epileptics: Gabapentin, pregabalin, tegretol
- Topical anesthetics: Lidocaine patches, capsaicin topically;
- Muscle relaxants: tizanidine
What are some characteristics of NSAIDS?
- Do NOT cross the blood-brain barrier
- 95-99% are bound to albumin
- Act mainly on the periphery, but may have a central effect
- Extensively metabolized by the liver and have a low renal clearance
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Regular NSAIDs inhibit the synthesis of Thromboxane A2 (TXA2) by inhibiting COX-1 & thus inhibits COX-2 (inhibits prostaglandin G/H synthase enzymes, known also as COX; thereby inhibiting the synthesis of prostaglandin E, prostacyclin, and thromboxane. )
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What are some adverse effects associated with NSAIDS?
Since NSAIDs inhibit the production of not only COX-2, but also COX-1 (which synthesizes prostaglandins):
- NSAIDS can affect the kidneys because prostaglandins help to maintain GFR and blood flow.
- Prostaglandins also contribute to the modulation of renin release, excretion of water, and tubular ion transport.
- In patients with normal renal function NSAID-induced renal dysfunction is extremely rare.
- NSAIDS can affect platelets because platelets are very susceptible to COX inhibition, which also inhibits the endogenous pro-coagulant thromboxane. Long-term use of standard NSAIDs produces a consistently prolonged bleeding time, but the prolongation is mild and values tend to remain below the upper limits of normal.
- NSAIDS can cause GI toxicity (ulcer formation)
