Pain Flashcards
Allodynia meaning?
Perception of a nonnoxious stimulus as pain
Anesthesia meaning?
Abscence of all sensation
Anesthesia dolorosa meaning?
Pain in an area that lacks sensation
Dysesthesia
Unpleasent or abnormal sensation with or without a stimulus
Hyperesthesia
Increased response to mild stimulation
Hyperpathia
Hyperesthesia, allodynia, hyperalgesia
Hyperalgesia
Increased response to noxious stimulation
Hypesthesia
Reduced cutaneous senation
Neuralgia
Pain inthe distribution of a nerve or a group of nerves
Paresthesia
Abnormal sensation percieved without an apparent stimulus
Radiculopathy
Functional abnormality of one or more nerve roots
Acute pain causes:
- Injury
- Disease process
- Abnormal function of muscle or viscera
When pain fails to resolve because of either abnormal healing or inadequate treatment, it becomes…
Chronic
Superficial pain recieves input from:
Skin, subcutaneous tissues and mucous membranes
Deep pain recieves input from:
Muscles, tendons, joints or bones
True visceral pain typical location and type?-
- Midline, dull and diffuse
- Associated with abnormal sympathetic and parasympathetic activity
-> nausea, vomiting, sweating and changes in BP and HR
Parietal pain
- Sharp, stabbing pain
Chronic pain
Attenuated or absent neuroendocrine stress responses and have prominent sleep and affective disturbances
Can be neuropathic or nociceptive
Persistent postsurgical pain
Chronic pain continuing beyond the typical healing period of 1-2 months
Inflammatory pain examples:
Appendictis, rheumatoid arthritis, inflammatory bowel disease, herpes zoster
Inflammatory pain mediators:
cytokines, TNF, acids, lipids, mast cells, ATP, vasoactive amines
Types of nociceptors:
- Mechanonociceptors - pinch and pinprick
- Silent nociceptors - inflammation
- Polymodal mechanoheat nociceptors - excessive pressure, heat, noxious substances (bradykinin, histamine, seratonin, H+, K+, prostaglandins, caspaicin, adenosine triphosphate)
Nociceptive _ fibres from the esophagus, larynx and trachea travel with the ______ nerve to enter the ______ in the brainstem
C
vagus
nucleus solitarius
Describe neurons structures in the pain pathway:
- Primary afferent neurons are found in the dorsal root ganglia and contain an axon which bifurcates (one to the peripheral tissues and one to the dorsal horn)
- Second order neurons are found in the dorsal horn and cross the midline to reach the thalamus (in the contralateral spinothalamic tract)
Which are the main pain fibers?
Aδ (pain, temperature, touch), 2-5m diameter, 12-30 ms-1 conduction speed
(myelinated and fast)
C (dorsal root), pain, temprature, mechanoreceptors, reflex responses, 0.4-1.2m fibre diameter, 0.5-2ms-1 conduction speed
Excitatory neurotransmitters modulating pain:
Substance P, calcitonin gene-related peptide, glutamate, aspartate, ATP
Main excitatory pain neurotransmitters and their location:
- Glutamate - main CNS NT
- Substance P - DRG
Calcitonin gene-related peptide - DRG
Inhibitory neurotransmitters modulating pain:
Somatostatin, acetylcholine, enkephalins, B-endorphin, norepinephrine, adenosine, serotonin, GABA, glycine
Opiois drugs classification:
Full agonists - morphine, heroine, methadone, meperidine, codeine, fentanyl
Partial agonists - buprenorphine
Mixed agonists/ antagonists - butorphanol, nalbuphine, pantazocine
Full antagonists - Naloxone, naltrexone, methylnaltrexone
Non-opioid classification:
Salicylates
- Acetylsalicyclic acid (aspirin)
P-aminophenols
- Acetominophen
Proprionic acids
- Ibuprofen
- Naproxen
Indoles
- Indomethacin
COX-2 inhibitors:
- Celecoxib
Antidepressants are used for _______
Examples
Neuropathic pain
Escitalopram, Bupropion, Citalopram
ARDS diagnosis:
PaO2/FiO2 <300mmHg
