Anesthesia Student Survival Guide.pdf - Index of

416 ● AnesthesiA student survivAl Guide
supraspinal structures (i.e. the brain stem, thalamus, or cortex). Finally, the
perception of pain takes place at the level of the thalamus, somatosensory
cortex, anterior cingulate gyrus, insula, cerebellum, and frontal cortex. The thalamus
and somatosensory cortex are thought to allow for the localization of pain,
while the anterior cingulate gyrus is involved in the emotional response to the
stimulus. The insula, cerebellum, and frontal cortex allow for one to remember and
to learn from a painful experience and to develop avoidance behavior.
General Pain Definitions
When discussing acute and chronic pain, it is important to have a basic battery of
definitions to express the type and description of pain a patient is experiencing.
General Pain Types
nociceptive pain normal, acute pain perception evoked by short-lasting noxious stimuli in intact
tissue, in the absence of peripheral or central sensitization.
inflammatory pain Pain following tissue injury but with no neural injury.
neuropathic pain Pathophysiologic state of pain after neural injury resulting in peripheral and
central reorganization
Abnormal Pain Descriptor Definitions
Allodynia the perception of pain by a stimulus that is not normally painful
hyperalgesia the enhanced perception of pain by a normally painful stimulus
dysesthesia Abnormal sensations experienced in the absence of stimulation
Paresthesia An abnormal sensation (e.g. burning, pricking, tickling, or tingling)
Acute Versus Chronic Pain
The clinical definition of acute versus chronic pain is determined in a temporal
fashion with an arbitrary timeframe of 3–6 months defining the cutoff point
between acute versus chronic.
Acute pain can be defined as a noxious stimulus caused by injury or abnormal
functioning of viscera or musculature. It is usually noted following posttraumatic,
postoperative, obstetrical, and acute medical illnesses (i.e. myocardial infarction or
nephrolithiasis). It is typically classified as somatic or visceral in nature. Somatic
pain is caused by the activation of nociceptors in the skin, subcutaneous tissues,