Pain Management Flashcards
At what time frame following the postsurgical period does persistent postsurgical pain become defined as being “chronic pain”?
A. 1 to 2 weeks
B. 3 to 4 weeks
C. 1 to 2 months
D. 6 to 12 months
- C.
○ Persistent postsurgical pain is defined as chronic pain that continues beyond the usual recovery period of 1 to 2 months following surgery (well past the normal convalescence period expected for a particular/specific surgical procedure).
○ Chronic pain is defined as pain that has lasted longer than 3 to 6 months, though some other investigators have placed the transition from acute to chronic pain at 12 months.
⊙ The incidence of persistent postsurgical pain can often exceed an incidence of 30% after certain high-risk/surgically invasive procedures such as amputations, thoracotomy, mastectomy, and inguinal hernia repair.
○ Acute pain will typically last less than 30 days, chronic pain to more than 6 months duration, and subacute pain lasts from 1 to 6 months.
○ A popular alternative definition of chronic pain involving no arbitrarily fixed durations is “pain that extends beyond the expected period of healing.”
- Both surgical trauma and anesthetic administration techniques can modulate which of the following human stress responses?
A. Neuroendocrine
B. Metabolic
C. Inflammatory
D. All of the above
- D. Many perioperative factors can produce significant influence toward amplifying or decreasing the surgical stress response(s) such as neuroendocrine, metabolic, and inflammatory changes. These factors can be further modified by patient-specific contributions such as anxiety/depression, surgical history, surgical technique (open vs. laparoscopy), and anesthetic techniques (general vs. regional).
Nonsteroidal anti-inflammatory drugs (NSAIDs) are often used as part of “multimodal” analgesic therapy; some of the potential advantages include all of thefollowing, except
A. Decreases opioid requirements
B. Can decrease postoperative pain intensity
C. Indirect effect of decreasing opioid-related side effects
D. Can improve wound healing
- D. NSAIDs have not only many of the above-identified advantages, but also several potential side effects that the practitioner must remain cognizant of such as risk of gastrointestinal bleeding, renal injury, and the potential to impair wound healing.
- Type(s) of symptomatic painconditions that best describes “chronic” pain often includes
A. Neuropathic pain alone
B. Nociceptive pain alone
C. Neuropathic or nociceptive pain
D. Somatic or visceral pain
- C.
○ Chronic pain is most often defined as neuropathic and/or nociceptive in nature.
○ Chronic pain may be divided into nociceptive pain—caused by activation of nociceptors—and neuropathic pain—caused by damage to or malfunction of the nervous system.
⊙ Neuropathic pain is divided into peripheral (within the peripheral nervous system) and central (originating from the brain/spinal cord).
○ Peripheral neuropathic pain is often described as burning, tingling, electrical, stabbing, and/or pins and needles sensation(s).
○ Nociceptive pain is divided into superficial or deep, and deep pain into deep somatic and visceral pain.
○ Superficial pain is initiated by activation of nociceptors in the skin or superficial tissues. Deep somatic pain is initiated by stimulation of nociceptors in ligaments, tendons, bones, blood vessels, and muscles, and is described as dull, aching, poorly-localized pain.
⊙ Visceral pain originates in the internal organ system(s) of the body. Visceral pain may be well-localized, but often is difficult to locate, and several visceral regions can produce “referred” pain when damaged or inflamed, where the sensation is located in an area distant from the site of pathology or injury.
- At what levels does the modulation of pain by electrical stimulation result inthe activation of inhibitory fibers?
A. Nociceptor level alone
B. Spinal cord level alone
C. Only within the brain
D. All of the above
- D.
○ Modulation of pain can happen centrally or peripherally.
It can occur at the nociceptor level peripherally or centrally either in the spinal cord or in supraspinal structures.
These modulation effects can be either inhibitive or facilitative.
○ In the brain and the spinal cord, much of the information from the nociceptive afferent fibers results from excitatory discharges of multireceptive neurons.
○ Pain information in the central nervous system is controlled by ascending and descending inhibitory pathways (using endogenous opioids or other endogenous substances).
⊙ In addition, a powerful inhibition of pain-related information occurs in the spinal cord.
○ These inhibitory systems can be activated by brain stimulation and peripheral nerve stimulation.
○ However, pain is a complex perception that is influenced also by prior experience and by the context within which the noxious stimulus occurs.
○ This sensation is also influenced by emotional state.
- Activation of which of the following mechanisms and/or pathways best describes “central sensitization” at the level of the spinal cord?
A. Second-order wide dynamic range neurons
B. Dorsal horn neuron
C. Spinal cord reflexes
D. All of the above
- D.
○ Central sensitization is an enhancement in the function of neurons and circuits in nociceptive pathways, caused by increases in membrane excitability and synaptic efficacy as well as reduced inhibition and is a manifestation of the plasticity of the somatosensory nervous system in response to activity, inflammation, and neural injury.
⊙ Central sensitization is responsible for hyperalgesia and there are three mechanisms that have been identified at the level of spinal cord:
(1) windup of second-order wide dynamic range neurons,
(2) dorsal horn neuron receptor field expansion, and
(3) hyperexcitability of flexion reflexes.
A 26-year-old female undergoes a left stellate ganglion block for treatment of complex regional pain syndrome of the left hand. Twenty minutes after the block is placed, skin temperature in the left arm rises from 33 to 36.5°C. Venous engorgement of the left arm and hand, left eye papillary constriction, and drooping of theeyelid are observed. The pain is not relieved. Which of the following can best explain the block failure?
A. Pain-carrying fibers originated from right stellate ganglion
B. Pain-carrying fibers originated from middle cervical ganglion
C. Pain-carrying fibers originated from inferior cervical ganglion
D. Pain-carrying fibers originated from second thoracic ganglion
- D.
○ The stellate ganglion (cervicothoracic ganglion or inferior cervical ganglion) is a sympathetic ganglion formed by the fusion of the inferior cervical and first thoracic ganglion.
○ Stellate ganglion is located at the level of C7 (seventh cervical vertebra), anterior to the transverse process of C7, superior to the neck of the first rib, and just below the subclavian artery.
○ Complications of stellate block include intravascular injection, intrathecal/epidural injection, bleeding, pneumothorax, brachial plexus involvement, local anesthetics spread to recurrent laryngeal nerve, and osteomyelitis or mediastinitis (rarely).
- Chronic pain indications for insertion of a spinal cord stimulator include all of the following, except
A. Phantom pain
B. Complex regional pain syndrome
C. Chronic visceral pelvic pain
D. Compartment syndrome pain
- D.
○ A spinal cord stimulator is a device used to exert pulsed electrical signals to the spinal cord to control chronic pain, and additional applications include use in some motor disorders.
○ Spinal cord stimulation is most effective for neuropathic pain, of which some common indications include sympathetically mediated pain, phantom limb pain, ischemic pain due to peripheral vascular disease, peripheral neuropathies, and visceral pain.
○ Compartment syndrome pain often requires urgent evaluation and possible need for emergency fasciotomy.
- The term used to best describe the PAIN condition “perception toward ordinary non-noxious stimulus as being painful” is A. Hyperalgesia
B. Anesthesia dolorosa
C. Hypalgesia
D. Allodynia
- D.
○ Hyperalgesia is an exaggerated response to noxious stimuli, an extreme and exaggerated reaction to a stimulus which is normally painful.
○ Anesthesia dolorosa is pain in area that has no sensation, is pain felt in an area (usually of the face) that is completely numb to touch with the pain described as constant, burning, aching, or severe.
○ Hypalgesia equals reduced sensitivity to pain, the opposite of hyperalgesia.
○ Allodynia is defined as pain due to a stimulus that does not normally provoke pain.
○ Temperature or physical stimuli can provoke allodynia (which may feel like a burning sensation) and can often occur after injury.
- Incorrect statement related to the definition of an abnormal sensation is
A. Dysesthesia is an abnormal sensation with or without a stimulus
B. Paresthesia is abnormal sensation without a stimulus
C. Neuralgia is due to abnormality in nerve roots
D. Hyperesthesia is an abnormal sensation of exaggerated response to mild stimulation
- C.
○ Dysesthesia is an abnormal sensation with or without a stimulus and is defined as an unpleasant, abnormal sense of touch and often presents as pain (may also present as an inappropriate, but not discomforting, sensation).
○ Dysesthesia is caused by lesions of the nervous system (peripheral or central) and involves sensations (spontaneous or evoked) such as burning, wetness, itching, electric shock, and pins and needles.
○ Dysesthesia can include sensations in any bodily tissue, including most often the mouth, scalp, skin, or legs.
○ Paresthesia is abnormal sensation without a stimulus with a sensation of tingling, tickling, prickling, pricking, or burning of a person’s skin with no apparent long-term physical effect.
○ The manifestation of a paresthesia may be transient or chronic.
○ The most familiar kind of paresthesia is the sensation known as “pins and needles” or of a limb “falling asleep.”
○ Neuralgia is pain sensation in the distribution of a nerve or a group of nerves (radiculopathy is pain secondary to nerve roots pathologies).
○ Neuralgia is pain in one or more nerves caused by a change in neurological structure or function of the nerves rather than by excitation of healthy pain receptors.
○ Neuralgia falls into two categories: central neuralgia (the cause of the pain is located in the spinal cord or brain) and peripheral neuralgia.
○ Hyperesthesia is exaggerated response to mild stimulation or a condition that involves an abnormal increase in sensitivity to stimuli of the sense.
- Which of the following clinical diagnoses best describes deafferentation pain?
A. Herniated disk
B. Amputation
C. Neuropathic pain
D. Diabetic neuropathy
- B.
○ Deafferentation pain is a type of neuropathic pain that is associated with loss of sensory input from the periphery to the central nervous system, such as phantom limb pain.
○ It is the interruption or destruction of the afferent connections of nerve cells (e.g., in animal experiments, deafferentation demonstrates the spontaneity of locomotor movement by the freeing of a motor nerve from sensory components).
- Gasserian ganglion block is most commonly used for neuropathic pain located in which of the following nerve distributions?
A. Facial nerve
B. Trigeminal nerve
C. Glossopharyngeal nerve
D. Vagal nerve
- B.
○ The gasserian ganglion is formed from two roots that exit the ventral surface of the brainstem at the midpontine level, and these roots pass in a forward and lateral direction in the posterior cranial fossa across the border of the petrous bone.
○ They enter a recess called Meckel cave, which is formed by an invagination of the surrounding dura mater into the middle cranial fossa.
○ The dural pouch that lies just behind the ganglion is called the trigeminal cistern and contains cerebrospinal fluid.
○ The gasserian ganglion is canoe-shaped, with the three sensory divisions—the ophthalmic (V1), the maxillary (V2), and the mandibular (V3)—exiting the anterior convex aspect of the ganglion.
○ A small motor root joins the mandibular division as it exits the cranial cavity via the foramen ovale.
○ The gasserian ganglion contains the cell bodies of sensory fibers of trigeminal nerve.
○ This procedure called a gasserianganglion block to treat facial pain is where a small amount of local anesthetic (with or without steroid) is injected onto the part of the nerve supply to the face called the gasserian ganglion (located to the back of the face between the ear and eye socket).
- Major excitatory neurotransmitters responsible for pain modulation include all the following, except
A. Substance P
B. Glutamate
C. Somatostatin
D. Aspartate
- C.
○ Substance P, glutamate, aspartate, and ATP are among the major excitatory molecules responsible for pain modulation.
○ Somatostatin, acetylcholine, and endorphin are among the major inhibitory mediators of pain.
- All the following are inhibitory neurotransmitters in the pain pathway, except
A. Norepinephrine
B. Adenosine
C. Serotonin
D. Calcitonin gene-related peptide
- D.
○ Norepinephrine, adenosine, and serotonin are among the major inhibitory neurotransmitters in the pain cascade.
○ However, calcitonin gene-related peptide is an excitatory neurotransmitter.
- Incorrect statement regarding secondary hyperalgesia is
A. It is caused by neurogenic inflammation
B. It is associated with Lewis’ triple response
C. It is increased by injection of local anesthetics
D. It is increased by application of capsaicin
- A.
○ Secondary hyperalgesia is defined as an increase in pain sensitivity when a noxious stimulus is delivered to a region surrounding, but not including, the zone of injury (increased pain sensitivity outside of the area of injury or inflammation).
○ Secondary hyperalgesia, also known as neurogenic inflammation, is associated with local redness, tissue edema, and sensitization to noxious stimuli.
○ Local anesthetics injection or capsaicin topical application can diminish these reactions.
○ Secondary hyperalgesia is a centrally mediated condition that may occur due to injury or disease in an area of the body.
○ Secondary hyperalgesia is due to central neuron sensitization and requires continuous nociceptor input from the zone of primary hyperalgesia for its maintenance.
○ Secondary hyperalgesia implies only mechanical hyperalgesia (e.g., allodynia and pin prick).