Misc. Pain Topics Flashcards
What is Allodynia?
Pain due to a stimulus that does not normally produce pain
What is an example of Allodynia?
Fibromyalgia
What is Alogenic?
A stimulus that is normally expected to produce pain
What is an example of allogenic pain?
Surgical incision
What is analgesia?
No pain is sensed in response to a stimulus that produces pain
What is an example of analgesia?
Opioid analgesics relieve pain caused by ICH
What is dysesthesia?
An abnormal and unpleasant sense of touch
What is an example of Dysesthesia?
Burning sensation from diabetic neuropathy
What is hyperalgesia?
Exaggerated pain response to a painful stimulus
What is an example of hyperalgesia?
Opioid induced hyperalgesia from burn pain from opioids
What is neuralgia?
Neuralgia is pain localized to a dermatome
What is an example of neuralgia?
Herpes Zoster (shingles)
What is neuropathy?
Impaired nerve function
What is an example of neuropathy?
Silent myocardial ischemia from diabetic neuropathy
What is paresthesias?
Abnormal sensation described as pins and needles
What is an example of paresthesias?
Nerve stimulation during regional anesthesia
Numbness and tingling from a stroke
Describe complex regional pain syndrome.
Complex Regional Pain Syndrome is characterized by neuropathic pain with autonomic involvement.
Risk factors include:
- Female Gender
- Previous Trauma
- Previous Surgery
Type 1 (Reflex Sympathetic Dystrophy)
Type 2 (Causalgia)
The key distinction is that type 2 is always preceded by nerve injury but type one is not.
What are some treatment modalities for chronic regional pain syndrome?
Ketamine infusion
Memantine (another NMDA antagonist)
Gabapentin
Regional sympathetic block
Physical therapy
Steroids
Amitriptyline
What are some drugs used to treat chronic pain?
Answer: Tricyclic antidepressants, SSRI, SNRI
Tricyclic antidepressants: Amitriptyline, Nortriptyline, Imipramine
SNRI: Venalfaxine, Duloxetine, milnacipran
SSRI: Fluoxetine, Citalopram
What can the combination of SNRI and SSRIs cause?
Answer: Serotonin Syndrome
Serotonin syndrome is a potentially life-threatening drug-induced toxidrome associated with increased serotonergic activity in both the PNS and CNS.
It is characterized by dose-relavent spectrum of:
- free serotonin
S/sx of Serotonin syndrome include:
Describe a thoracic paravertebral block
Answer: LA is infected into the paravertebral space (a potential space) targets the ventral ramus of the spinal nerve as it exits the vertebral foramen
Creates a unilateral sensory and sympathetic block along that specific dermatome.
Think of the paravertebral block as a single shot, unilateral epidural block.
You have to perform one block t each dermatome to be anesthetized
When are the best times to utilize a thoracic paravertebral block?
Breast surgery, Thoracotomy and Rib Fracture
What is the celiac plexus block utilized for?
Answer: Useful for management of cancer pain of the upper abdominal organs
Some examples include the:
- Distal esophagus
- Stomach
- Liver
- Pancreas
- Small intestine
- Colon (except the descending colon)
What are some examples of complications with the celiac plexus block?
Orthostatic Hypotension
Retroperitoneal hematoma
Hematuria
DIarrhea
AAA dissection
Back pain
Retrograde migration of the inject ate (problem if a neurolytic is used)
What is the superior hypogastric plexus block useful for?
Answer: the block is useful for the management of cancer pain of the pelvic organs
Examples include: uterus, ovaries, prostate and descending colon
What are some complications that can be associated with the superior hypogastric plexus block?
A complication of the superior hypogastric plexus block include retrograde migration of the inject ate (a problem if a neurolytic is used)
What is a sphenopalatine block useful for?
Answer: A sphenopalatine block can be used to relieve postural puncture headaches.
What is a retrobulbar block?
Answer: The optic nerve is unique because it is the only cranial nerve that is part of the central nervous system (it’s enveloped by the meningeal sheath and bathed in CSF).
because of this, a LA is injected into the optic sheath is permitted direct entry to the brain
It is like giving a subarachnoid block in the optic sheath
How does the LA work in a retrobulbar block?
LA is injected into the optic sheath can migrate towards the optic chasm where it anesthetizes CN2 and 3 on the opposite side of the block. This results in contralateral amaurosis (blondness)
LA that reaches the brainstem can cause APNEA (post-retrobulbar block apnea syndrome).
This complication typically becomes evident 2-5 minutes after injection. Spontaneous ventilation usually resumes in 15-20 minutes, but a full recovery may require up to an hour
What is it important to assess in the retrobulbar block before performing?
Answer: the contralateral pupil before performing a retrobulbar block. If the pupil starts small but dilates shortly after the block, you should anticipate the development of post-retrobulbar block apnea syndrome
** BE READY TO PROVIDE CARDIOPULMONARY SUPPORT UNTIL LA IS CLEARED FROM CSF ***
