ANESTHESIA: PAIN (AB) Flashcards
What is the most common symptom prompting a medical consult?
Pain
How does the International Association for the Study of Pain (IASP) define pain?
An unpleasant sensory and emotional experience associated with actual or potential tissue damage
What are the two main categories of pain according to duration?
Acute pain and Chronic pain
What is acute pain primarily due to?
Nociception or painful stimulus
What factors often play a major role in chronic pain?
Psychological and behavioral factors
Who stated that pain should be assessed as the 5th vital sign?
Dr. James Campbell
What organization trademarked “Pain as the 5th Vital Sign”?
American Pain Society
What are the 4 traditional vital signs?
Blood pressure, heart rate, respiratory rate, body temperature
What is allodynia?
Perception of an ordinarily non-noxious stimulus as pain
What is analgesia?
Absence of pain perception
What is anesthesia?
Absence of all sensation
What is anesthesia dolorosa?
Pain in an area that lacks sensation
What is dysesthesia?
Unpleasant or abnormal sensation with or without a stimulus
What is hypalgesia (hypoalgesia)?
Diminished response to noxious stimulation
What is hyperalgesia?
Increased response to noxious stimulation
What is hyperesthesia?
Increased response to mild stimulation
What is hyperpathia?
Presence of hyperesthesia , allodynia, and hyperalgesia with overreaction and persistence after stimulus
What is hypesthesia (hypoesthesia)?
Reduced cutaneous sensation
What is neuralgia?
Pain in the distribution of a nerve or group of nerves
What is paresthesia?
Abnormal sensation perceived without an apparent stimulus
What is radiculopathy?
Functional abnormality of one or more nerve roots
What are the three types of pain recognized since 2019?
Nociceptive , Neuropathic, Nociplastic
What causes nociceptive pain?
Activation or sensitization of peripheral nociceptors
What causes neuropathic pain?
Injury or acquired abnormalities of peripheral or central neural structures
What are the common causes of acute pain?
Trauma , surgery, labor, myocardial infarction, pancreatitis, renal calculi, gallbladder stone
What are the four physiological processes of the pain pathway?
Transduction , Transmission, Perception, Modulation
What is transduction in the pain pathway?
Transformation of stimulus into a neuroelectric signal (action potential)
What is transmission in the pain pathway?
Propagation of action potential along A-delta and C pain fibers
Which fibers are responsible for sharp localized pain?
A-delta fibers
Which fibers are responsible for dull poorly localized pain?
C fibers
Which brain area is associated with the sensory aspects of pain?
Somatosensory cortex
Which brain structures are involved in emotional perception of pain?
Limbic nuclei and reticular formation
What emotions do the limbic nuclei mediate during pain?
Sadness and crying
What is modulation in the pain pathway?
Neural process that reduces activity in the pain transmission system
Which neurotransmitters are involved in pain modulation?
Serotonin and norepinephrine
What theory explains how large fiber input can inhibit pain?
Gate control theory
Where are the cell bodies of primary afferent neurons located?
Dorsal root ganglia
What are the three neuronal pathways involved in pain conduction?
Primary afferent neurons , Second-order neurons, Third-order neurons
Where do second-order neurons synapse?
Thalamic nuclei
Where do third-order neurons send projections?
Postcentral gyrus of cerebral cortex
What is the receptor for Substance P?
Neurokinin-1 receptor
What is the effect of Substance P on nociception?
Excitatory
What is the effect of calcitonin gene-related peptide (CGRP) on nociception?
Excitatory
Which receptors do glutamate and aspartate act on?
NMDA , AMPA, kainate, quisqualate
What is the effect of ATP on nociception?
Excitatory
Which neuropeptides are important for pain transmission?
Substance P and calcitonin gene-related peptide (CGRP)
How does Substance P facilitate pain transmission?
Activates neurokinin-1 receptors
What substances does Substance P release from mast cells and platelets?
Histamine and serotonin
Which receptors are found on unmyelinated peripheral nerves?
Opioid and α2-adrenergic receptors
What neurotransmitter does Midazolam act on?
GABA
What receptor does Ketamine block?
NMDA receptor
What do local anesthetics block?
Sodium-gated channels
Which drugs act at the transduction stage of the pain pathway?
NSAIDs , Opioids, Local Anesthetics
Which drugs act at the transmission stage of the pain pathway?
Opioids , Local Anesthetics, Anticonvulsants, Acetaminophen
Which drugs act at the perception stage of the pain pathway?
Opioids , General Anesthetics, Alpha-2 Agonists
Which drugs act at the modulation stage of the pain pathway?
Opioids , Alpha-2 Agonists, NMDA Antagonists, Antidepressants, SCS, PNS
Which anticonvulsants are used in pain transmission?
Gabapentin and Carbamazepine
Which alpha-2 agonists are used for pain perception and modulation?
Clonidine and Dexmedetomidine
What are examples of non-drug pain modulation techniques?
SCS (spinal cord stimulation) , PNS (peripheral nerve stimulation), TENS, acupuncture
What are the two main types of acute (nociceptive) pain?
Somatic pain and visceral pain
How is somatic pain classified?
Superficial or deep
What is superficial somatic pain?
Pain from skin, subcutaneous tissues, and mucous membranes; well localized, sharp, pricking, throbbing, or burning sensation
How is deep somatic pain described?
Dull, aching, less well localized; arises from muscles, tendons, joints, or bones
What causes visceral pain?
Disease process or abnormal function involving internal organs or their coverings (e.g., parietal pleura, pericardium, peritoneum)
What are the four subtypes of visceral pain?
True localized visceral pain, localized parietal pain, referred visceral pain, referred parietal pain
How is true visceral pain described?
Dull, diffuse, usually midline; associated with abnormal autonomic activity like nausea, vomiting, sweating, changes in BP and HR
How is parietal pain described?
Sharp, stabbing; either localized around the organ or referred to a distant site
What defines chronic pain?
Pain persisting beyond usual healing time (typically 1-6 months), may be nociceptive, neuropathic, or mixed
What psychological factors are associated with chronic pain?
Mental affectation or disorder, environmental factors
What is neuropathic pain?
Paroxysmal, lancinating, burning pain with hyperpathia (painful response to normally harmless stimulus)
What is deafferentation pain?
Neuropathic pain associated with loss of sensory input (e.g., phantom limb sensation after amputation)
What is sympathetically maintained pain?
Neuropathic pain where sympathetic nervous system plays a major role
What is the WHO Analgesic Ladder?
Three-step guideline for managing cancer and chronic non-cancer pain using non-opioids, weak opioids, and strong opioids
What is Step 1 of the WHO Analgesic Ladder?
Mild pain: Non-opioid analgesics (NSAIDs or acetaminophen) with or without adjuvants
What is Step 2 of the WHO Analgesic Ladder?
Moderate pain: Weak opioids (codeine, tramadol) with or without non-opioids and adjuvants
What is Step 3 of the WHO Analgesic Ladder?
Severe pain: Strong opioids (morphine, methadone) with or without non-opioids and adjuvants
What are the key components of pain evaluation?
Location, onset, quality, alleviating/exacerbating factors, history, previous therapies, symptom changes
What does a numerical pain rating scale measure?
Pain intensity from 0 (no pain) to 10 (worst pain)
What are the pain intensity ranges in numerical scale?
1-4: mild, 5-7: moderate, 8-10: severe
What is the Wong-Baker FACES scale used for?
Assessing pain in pediatric patients
What is the Faces Pain Scale-Revised (FPS-R)?
Self-report pain scale for children 4-16 years, scored on 0-10 metric
What is the McGill Pain Questionnaire (MPQ)?
Checklist of descriptive words for pain categorized into sensory, affective, evaluative, and miscellaneous
What are the three major dimensions of MPQ?
Sensory-discriminative, motivational-affective, cognitive-evaluative
What is the Visual Analog Scale (VAS)?
10-cm line from ‘no pain’ to ‘worst pain imaginable’, patient marks intensity
When is psychosocial evaluation of pain useful?
When pain intensity/characteristics are disproportionate to disease, or psychological/social issues are suspected
What is somatization disorder?
Physical symptoms without medical explanation causing distress and impairment
What is conversion disorder?
Sensory/motor symptoms suggestive of medical condition but explained by psychological factors
What is hypochondriasis?
> 6 months preoccupation with fear of serious illness despite medical reassurance
What is malingering?
Intentional production of symptoms for external gain (e.g., avoiding work)
What are substance-related disorders in chronic pain?
Habitual misuse of substances driving pain complaints and drug-seeking behavior
What are common conditions associated with neuropathic pain?
Diabetic neuropathy, phantom limb, postherpetic neuralgia, CVA, SCI, MS
What are mechanisms of neuropathic pain?
Spontaneous neuron activity, mechanosensitivity, ephaptic transmission, dorsal horn reorganization, thalamic activity
What is possible neuropathic pain based on?
History of neurological lesion/disease and neuroanatomically plausible pain distribution
What is probable neuropathic pain based on?
History plus sensory signs in neuroanatomically plausible area
What is definite neuropathic pain based on?
Diagnostic test confirming somatosensory lesion/disease explaining pain
What is nociplastic pain?
Pain from altered CNS processing, not purely nociceptive or neuropathic
What are symptoms of nociplastic pain?
Multifocal pain, CNS-derived fatigue, sleep, memory, mood issues
What are examples of nociplastic pain conditions?
Fibromyalgia, tension headache, mixed chronic low back pain
What are criteria for probable nociplastic pain?
Chronic regional pain, no evidence of nociceptive/neuropathic cause, pain hypersensitivity, comorbidities (sleep, cognitive, sensory issues)
What is preemptive analgesia?
Analgesia given before noxious stimulus to block CNS hyperexcitability and reduce postoperative pain
Who proposed the concept of preemptive analgesia?
George Washington Crile
What is preventive analgesia?
Broad analgesic strategy covering preoperative, intraoperative, and postoperative periods to prevent central sensitization
What is multimodal analgesia?
Combining multiple analgesic techniques to enhance pain control and minimize side effects
Why is pain considered a personal experience?
Influenced by biological, psychological, and social factors
How do pain and nociception differ?
Nociception is sensory input; pain includes emotional experience
Can pain be inferred from sensory neuron activity alone?
No, pain has psychological and emotional components
What does the inability to communicate indicate about pain?
It does not negate the possibility that the person is experiencing pain
What is hyperpathia?
Exaggerated pain response to normally harmless stimuli
What is ephaptic transmission?
Cross-talk between nerve fibers after demyelination, causing non-noxious stimuli to trigger pain
What is the role of epigenetics in pain management?
Individual pain experiences and responses vary due to genetic and environmental factors
