Pain Flashcards
The International Association for the Study of Pain defines pain as…
“an unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage”
The management of chronic pain follows which algorithm?
The management of chronic pain follows the WHO analgesic ladder, a three-step algorithm and set of guiding principles based on using pharmacologic agents sequentially, escalating from nonopioids for mild pain to strong opioids for severe pain, in accordance with the degree of pain as reported by the patient.
Acute vs chronic pain
Acute pain = A warning signal indicating actual or potential tissue damage that triggers a protective reaction.
Typically associated with trauma, surgery, and acute illness.
Chronic pain = Pain that lasts beyond the normal tissue healing time; (6 months according to the IASP)
Unlike acute pain, chronic pain has no protective role in preventing further tissue damage and can be considered a disease entity in its own right.
Types of pain
Nociceptive pain
Neuropathic pain
What is referred pain?
Definition: pain that is perceived at a location other than that of the causative stimulus; projection of pain usually onto a specific dermatome or myotome of the corresponding segment of the spinal cord
Common examples of referred pain
Right shoulder pain in patients with cholecystitis or perforated PUD
Kehr sign: left shoulder pain associated with diaphragmatic irritation resulting from hemoperitoneum (classically secondary to splenic rupture)
Left-sided chest and arm pain: myocardial infarction
Periumbilical pain in the early stages of appendicitis
Overview of referred pain
Abbey Pain Scale - when is this used?
Assesses pain in patients with advanced dementia
Nociception vs pain
Nociception - pain pathway is activated
Pain - what the patient says hurts
…-order neurones – These are pseudounipolar neurones which have cells bodies within the dorsal root ganglion. They have one axon which splits into two branches, a peripheral branch (which extends towards the peripheries) and a central branch (which extends centrally into the spinal cord/brainstem).
First-order neurones – These are pseudounipolar neurones which have cells bodies within the dorsal root ganglion. They have one axon which splits into two branches, a peripheral branch (which extends towards the peripheries) and a central branch (which extends centrally into the spinal cord/brainstem).
…-order neurones – The cell bodies of these neurones are found in the Rexed laminae of the spinal cord, or in the nuclei of the cranial nerves within the brain stem. These neurones then decussate in the anterior white commissure of the spinal cord and ascend cranially in the spinothalamic tract to the ventral posterolateral (VPL) nucleus of the thalamus.
Second-order neurones – The cell bodies of these neurones are found in the Rexed laminae of the spinal cord, or in the nuclei of the cranial nerves within the brain stem. These neurones then decussate in the anterior white commissure of the spinal cord and ascend cranially in the spinothalamic tract to the ventral posterolateral (VPL) nucleus of the thalamus.
…-order neurones – The cell bodies of …-order neurones lie within the VPL of the thalamus. They project via the posterior limb of the internal capsule to terminate in the ipsilateral postcentral gyrus (primary somatosensory cortex). The postcentral gyrus is somatotopically organised. Therefore, pain signals initiated in the hand will terminate in the area of the cortex dedicated to sensations of the hand.
Third-order neurones – The cell bodies of third-order neurones lie within the VPL of the thalamus. They project via the posterior limb of the internal capsule to terminate in the ipsilateral postcentral gyrus (primary somatosensory cortex). The postcentral gyrus is somatotopically organised. Therefore, pain signals initiated in the hand will terminate in the area of the cortex dedicated to sensations of the hand.
… fibres are unmyelinated and a slow conduction speed
C fibres are unmyelinated and a slow conduction speed
… fibres are responsible for the secondary pain we feel which is often dull, deep, and throbbing in nature
C fibres are responsible for the secondary pain we feel which is often dull, deep, and throbbing in nature
Compared to Aδ fibres, C fibres have a … threshold for firing.
Compared to Aδ fibres, C fibres have a high threshold for firing.
WHO pain ladder - The World Health Organization (WHO) Pain Ladder has been an enduring guide for over 25 years. Its simple, progressive steps of 1) …, 2) …, and 3) …
The World Health Organization (WHO) Pain Ladder has been an enduring guide for over 25 years. Its simple, progressive steps of 1) anti-inflammatory agents, 2) weak opioids, and 3) strong opioids is still fundamentally sound.
