Post-op Pain Management Flashcards
What is the difference between primary and secondary hyperalgesia?
Primary - immediately surrounding a site of injury; secondary - occurs outside the immediate area of injury
Define allodynia
A painful response to a normally innocuous stimulus
What are the 5 steps of the pain pathway?
Transduction, transmission, modulation, projection, and perception
Define the step of pain transduction
Creation of the nociceptive signal
Define the step of pain transmission
The nociceptive signal (action potential) is transmitted to the spinal cord
What are the two types of nociceptive fibers and what types of signals do they transmit?
A delta - fast, sharp pain; C fibers - slow, dull pain
What are A beta fibers?
Normally transmit only low threshold, non-noxious stimuli (normal touch), but this response may be altered in chronic pain states
Where do nociceptive fibers synapse?
The dorsal horn of the spinal cord
Describe the step of pain modulation
Occurs in the spinal cord and is dependent upon many molecular mechanisms (neuron interactions, inter neurons, descending modulators pathways)
What does neuroplasticity mean?
The degree and duration of nociceptive stimulation alters the patient’s pain response
A long term noxious stimulus will cause activation of what type of receptors?
NMDA and AMPA; results in wind up/central sensitization and the development of chronic and neuropathic pain
Define the step of pain projection
Projection of the nociceptive signal to the brain via the spinal cord
Define the step of pain perception
The conscious perception of the noxious stimulus in the brain; without this step, pain has not truly occurred (ONLY nociception has), as pain is a CONSCIOUS process
Which nociceptive fibers are the smallest? Largest? Have the fastest conduction velocity?
C fibers; A beta; A beta
Describe visceral pain
mainly associated with smooth muscle/hollow organ nociceptors that respond to stretch, hypoxia and inflammation; characterized by poorly-localized and diffuse pain