Pain Flashcards
A-delta vs. C fibers
A delta: Sharp, localized transmission, FAST
C: Dull, aching, diffuse, SLOW
Gate Control Theory
A-alpha and A-beta fibers inhibit pain signals to the brain by stimulating an interneuron. E-stim and massage take advantage of gate theory.
Opiopeptins
AKA endorphins
Bind to opioid receptors > inhibit pain
Direct effect: control amount of Ca and K moving into and out of nerve during depolarization
Indirect effect: Inhibit GABA (GABA usually inhibits pain controlling structures like A-beta fibers)
McGill pain questionnaire
- Pt marks where pain is on body diagram
- Pt chooses one word to describe pain from each of twenty categories
- Pt describes pattern of pain, aggs and eases
- Pt rates intensity of pain 0-5
Valid, reliable, most widely used
Viscerogenic pain
- Thought to mimic musculoskeletal pain due to viscerosomatic convergence
- Doesn’t change with movement/positioning
- Often diffuse, poorly localized
- May be accompanied by other systemic symptoms (N/V, weight loss, pallor, diaphoresis)
Common sites of viscerogenic pain
shoulder, scapula, back, chest, pelvis, SI, groin, hip
MI referred pain
chest, mid back, shoulder, arm, neck, jaw
Heart innervation: C3-T4
Kehr’s sign
Pressure to upper abdomen, or supine positioning, recreates left shoulder pain
(Due to accumulation of blood in abdomen irritating diaphragm. Phrenic nerve = C345. Often due to splenic rupture)
Gall stone referred pain
Right upper abdomen, interscapular region. Sometimes right shoulder if diaphragm is irritated.
Gallbladder innervation = midthoracic spinal segments
Empty end feels
Joint inflammation
Fracture
Bursitis
Firm end feels (abnormal)
Increased tone
Tightening of capsule
Ligament shortening
Hard end feels (abnormal)
Fracture
OA
Osteophyte formation
Soft end feels (abnormal)
Edema
Synovitis
Ligament instability/tear
