pain and analgesics 1 Flashcards
define pain
pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage
it is a perception that occurs in the brain caused by the activation of nociceptors by thermal, mechanical, chemical or other stimuli
what are the types of nociceptive pain? how can they be divided?
cam be divided into visceral pain and somatic pain, referred pain, radiating pain, breakthrough pain, psychogenic pain, phantom pain
what is visceral pain?
is diffuse, difficult to locate, and often referred to a distant, superficial structure
what is somatic pain?
superficial pain: activation of nocieptors in the skin or other superficial tissue; sharp or burning, well defined
deep somatic pain; activation of nociceptors in ligaments, bones, tendons, fasciae, muscles, dull aching, poorly localized
what is referred pain?
perceived at a location other than the site of the painful stimulus
what is radiating pain?
pain that spreads from the original area outwards to another part of the body
what is breakthrough pain?
is a transitory flare up of pain against a background of otherwise well controlled pain
what is psychogenic pain?
result of some underlying psychological disorder
what is phantom pain?
refers to a patient’s experience of pain in a part of the body that has been removed surgically or traumatically
what is neuropathic pain?
pain that follows direct injury to a peripheral nerve
how is neuropathic pain characterised?
partial or complete damage to or dysfunction of the somatosenory pathways in the PNS AOR CNS and
the occurance of pain and hypersensitivity phenomena within the denerated zone and its surroundings
who is neuropathic pain observed in?
diabetics and in carpal tunnel syndrome or sciatica
following traumatic injury, inducing ischemia, radiation therapy, excessieve alcohol consumption, immune system disease, coeliac disease or viral infection
what are the different types of diabetic neurpathic pain?
peripheral- sensory neuropathy- feet/legs
autonomic- results from damage to nerves which controls involuntary functions
focal neuropathy- results from injury to a peripheral nerve at one site
what is neuropathic pain insensitive to?
morphine and other opioid drugs
how can neuropathic pain be significantly relieved?
TCA- Amityuptyline
anticonvulsant agents- carbamazepine
corticosteroids- dexamethasone- may produce substantial improvement in some cases in neurpathic pain associated with cancer
what is trigeminal neuralgia?
is a neuropathic facial pain condition
- pain/ loss of sensation in the face
- severe paroxysmal, lancinating facial pain
- triggered by innocuous stimuli
- a disorder of the 5th cranial nerve
what is the trigeminal nerve?
it is the 5th and largest of the 12 pairs of crianial nerves
the chief nerve of sensation for the face
contains sensory fibres for the face, as well as a motor segment important for mastication- chewing
what does the trigeminal nerve divide into?
3 brances:
1- ophthalmic division- V1- provides sensation to the forehead and eye
2-maxillary division-v2- provides sensation to the cheek, upper lip and roof of the mouth
3- mandibular division-V3- provides sensation to the jaw and lower lip