8 Pain and Its Assessment Flashcards
Duration of chronic pain
> 3 months (longer than expected healing time)
Detect sensory input to peripheral tissues including the skin, muscles, and joints, and relay that sensory information to the central nervous system
Primary sensory neurons
Neurons in the spinal cord that relay information to the thalamus and various midbrain structures
Second-order neurons
Pain fibers: Thickly myelinated and fast conducting nerve fibers
Low-threshold Aβ fibers
Pain fibers: Unmyelinated or thinly myelinated and slower conducting
High-threshold C and Aδ fibers
Stimuli that cause (or at least have the potential to cause) tissue damage
Noxious stimuli
Noxious stimuli are sensed by these pain fibers
High-threshold C and Aδ afferents called nociceptors
Pain evoked by activation of high-threshold C and Aδ afferents
Nociceptive pain
Nociceptive pain normally serves an important protective role by
Triggering withdrawal from the noxious stimulus and teaching one to avoid such stimuli in the future, thus minimizing injury in the short and long term
Increases the excitability of nociceptors
Peripheral sensitization
Consequences of peripheral sensitization
1) Hyperalgesia: a hyperexcitable nociceptor responds more vigorously than normal to a noxious stimulus, resulting in hyperalgesia, or exaggerated pain in response to noxious stimulation
2) Allodynia: reduction of its threshold allows a nociceptor to be activated by weaker-than-normal stimuli, resulting in allodynia, or pain in response to innocuous stimulation
3) a sufficiently large reduction in threshold will cause the nociceptor to become spontaneously active, generating action potentials in the absence of any sensory input and causing spontaneous pain
Biochemicals that sensitize nociceptors
Prostaglandins
Tumor necrosis factor-alpha (TNF-α)
Interleukin 1β (IL-1β)
IL-6
Vicious cycle of inflammation caused by release of cytokines from immune cells
Neurogenic inflammation
Neurogenic inflammation can be exacerbated by the release of proinflammatory peptides like
Calcitonin gene-related peptide (CGRP) and P from activated nociceptors
Causes pain signals to be amplified, but through changes occurring in the central nervous system
Central sensitization
Heightened pain sensitivity that is limited to sites of inflammation resulting from sensitized peripheral neurons innervating inflamed areas
Primary hyperalgesia
Peripheral vs Central sensitization: causes heightened pain sensitivity that extends beyond sites of inflammation
Central
Peripheral vs Central sensitization: causes heightened pain sensitivity that affects only the neurons innervating inflamed areas
Peripheral sensitization causing primary hyperalgesia
T/F Peripheral and central sensitization are not mutually exclusive
T, the former often contributes to the latter
Factors associated with children and adolescents’ chronic pain (biopsychosocial model of pain)
Social factors
Psychological factors
Biological factors
Environmental factors
T/F Susceptibility to such neuroplas- tic changes has a strong genetic and epigenetic component, and the latter can reflect a broad range of environmental factors such as traumatic early life experiences
T
Aβ, Aδ, or C fibers: Thickly myelinated
Aβ
Aβ, Aδ, or C fibers: Thinly myelinated
Aδ and C
Aβ, Aδ, or C fibers: Large diameter
Aβ
Aβ, Aδ, or C fibers: Medium diameter
Aδ
Aβ, Aδ, or C fibers: Small diameter
C fibers
Aβ, Aδ, or C fibers: Fast conducting
Aβ
Aβ, Aδ, or C fibers: Medium conducting
Aδ
Aβ, Aδ, or C fibers: Slow conducting
C fibers
Aβ, Aδ, or C fibers: Light touch
Aβ
Aβ, Aδ, or C fibers: Pain
Aδ, or C fibers
Aβ, Aδ, or C fibers: Temperature
Aδ, or C fibers
Aβ, Aδ, or C fibers: Itch
Aδ, or C fibers
Primary afferent fibers
Aβ, Aδ, C fibers
Last part of the brain where sensory input for pain is processed
Prefrontal cortex
Sensory afferents and nervous system
Primar afferents
Spinal cord
Thalamus
1) Primary somatosensory cortex-Secondary somatosensory cortex
2) Secondary somatosensory cortex
3) Anterior cingulate cortex-Prefrontal cortex or Amygdala
4) Insula
a) Anterior cingulate cortex-prefrontal cortex
b) Amygdala
Under normal conditions, noxious stimulus results in what pain
Nociceptive
When there is peripheral sensitization, noxious or innocuous stimuli can result in
Primary hyperalgesia
Primary allodynia
Spontaneous pain
When there is central sensitization, noxious stimuli can result in
Secondary hyperalgesia
When there is central sensitization, innocuous stimuli can result in
Secondary allodynia
the more immediate reaction to nociception and is more midbrain based
Emotion
How cognitions amplify the experience of pain
attach meaning to the emotional experience and can trigger additional emotional reactions
Cognitive coping strategies that are related to greater pain and emotional distress
1) Emotion-focus avoidance (catastrophizing and expressing negative emotions)
2) Cognitive self-instruction (primarily wishful thinking)
Cognitive coping strategies that are associated with less pain
1) Cognitive refocusing (distraction)
2) Feelings of self-control over pain
The first step in the effective management of pain
Pain assessment
Self-reported measures of pain routinely used as a key outcome in composite measures of JIA
None
When should pain be assessed among rheuma patients
Pain should be assessed in all patients at the first visit and at each subsequent visit
The best predictor of whether an individual patient is able to accurately self-report pain
Chronological age
Most children of this age are able to self-report their current pain when provided with a developmentally appropriate tool
5 to 6 years and above
Used to assess pain for children younger than 5 years and/or patients with cognitive impairment or communication difficulties
An observational pain measure
Pain scale: asks children to rate pain intensity on scale of 0 to 10
11-point Numerical Rating Scale (NRS-11)
Pain scale: includes six faces from “no pain” to “very much pain”
Faces Pain Scale-revised (FPS-R)
Pain scale: moves a slider along the length of the scale to indicate how much pain they have
Color Analog Scale (CAS)
2 pain scale measures with low recommendation
VAS and NRS-11
Pain scale measure recommended for children younger than 6
None
MC used self-report pain scale intended for use in children 5-18 years and takes 10-15 min
Pediatric pain questionnaire (PPQ)
A well-validated multidimensional instrument that can aid in the comprehensive assessment of chronic musculoskeletal pain in adolescents (social functioning, physical functioning, depression, general anxiety, pain-specific anxiety, family functioning, and development)
Bath Adolescent Pain Questionnaire (BAPQ), which has adolescent and parent versions
A web- and mobile-based tool for the visual self-report and electronic tracking of sensory pain where patients can choose from a library of pain-quality icons to express different types of pain, can be assigned a rating of intensity (0 to 10 NRS) and then dragged- and-dropped onto a detailed virtual body map to show pain location
Pain-QuILT
Observational behavioral measure intended for children 2 months to 8 years that is used routinely for acute pain
r-FLACC
The r-FLACC behavioral scale uses these indicators to assess pain (FLACC)
1) Facial expression
2) Leg movement
3) Activity
4) Cry
5) Consolability
Therapeutic strategy for pain that seeks to engage the child as an agent of change in his or her care and is typically delivered weekly by specially trained psychologists over the course of several months
cognitive-behavioral therapy (CBT)
T/F Evidence suggests that exercise exacerbates arthritis
F, an updated Cochrane meta-anal- ysis of existing RCTs found that exercise does not exacerbate arthri- tis; however, this analysis also failed to identify significant evidence of improvements in pain
