Interventional approaches for Chronic Pain Flashcards
1
Q
Indications for interventional pain therapies
A
- Uncontrolled pain despite systemic analgesics
- Unacceptable systemic analgesic adverse effects
2
Q
Trigger point injections
A
- myofascial pain
- trigger point on exam
- hyperirritable nodule in skeletal muscle
- pain on palpation, compression
- refers pain
- local anesthetic injected
- dry needling
- acupuncture
- botox
3
Q
Botox
A
- neuroparalytic agent produced from clostridium botulinum
- inhibits acetylcholine release at NMJ
- used for migraine, interstitial cystitis, chronic myofascial pain
- spasticity
- q12 weeks to minimize antibody development
4
Q
Peripheral nerve blocks
A
- plexopathy or peripheral nerve
- repeated injections
- continuous infusion with catheter placed
- Risk:
- infection
- local anesthetic toxicity
- displacement
- knotting
5
Q
Neurolytic blocks:
Chemical
A
- alcohol and phenol
- anesthetic and neurolytic effects
6
Q
Neurolytic blocks:
Radiofrequency ablation or pulsed treatment
A
- FR neurotomy
- heat destruction of neural tissue
- high frequency electrical current
- Uses:
- spinal facet
- trigeminal ganglia
- dorsal root ganglia
- spinal sympathetic ganglia
- pulsed radiofrequency
- high voltage bursts
- some thermal damage
- neuromodulation
- better for trigger points, dorsal root ganglia, peripheral neuropathy
7
Q
Sympathetic nervous system block :
Celiac Plexus Block
A
- Visceral pain from pancreatic cancer, upper abdominal tumours
- May reduce opioid use and SE
- 80-90% relief x 3 months
- percutaneous or CT guided, or endoscopically done
- outpatient treatment
- SE:
- transient diarrhea
- orthostatic hypotension
- rare : paralysis, arotic dissection
8
Q
Lumbar Sympathetic Blocks
A
- injection through anterolateral aspect of vertbral body on ispilateral side of pain
- Indications :
- kidney pain
- intractable lower extremity pain
- PVD
- leg ulcers
- CRPS
- phantom pain
- diabetic neuropathy
- testicular pain
- reduces rest pain, increased cutaneous blood flow
- 6 months relief
9
Q
Stellate Ganglion Block
A
- collection of sympathetic nerves in neck at C6-7 level.
- located in front of vertbral body
- Useful for :
- refractory angina
- CRPS
- PVD
- Raynaud’s brachial plexus
- Pain in face, head, arms and chest
- alternative is T2-T3 paravertebral sympathectomy by RF ablation
10
Q
Superior hypogastric plexus block
Sympathetic blockade
A
- Pelvic visceral pain from gyne, colorectal, GU ca
- long lasting relief
11
Q
Ganglion Impar Block
A
- Intractable perineal pain
12
Q
Sympathetic blockade : MOA
A
- Interruption of afferent sympathetic nerves
13
Q
Neuraxial Neurolysis
A
- chemical posterior rhizotomy
- Subarachnoid neurolysis
- few dermatomes only
- advanced cancer
- surgical or chemical cordotomy
- upper lumbar, lower thoracic dermatomes
- high complication rates,
- may be acceptable for severe pain at EOL
- sensory, motor, autonomic derangements
- ineffective relief
- motor weakness
- incontinence
- Not helpful for extensive, poorly localized pain or neuropathic pain
14
Q
Spinal Analgesia
A
- Peripheral nociceptors of afferent first order neurons in spine
- alpha adrenegic
- opioid
- GABA
- Ca2+ channels
- release of glutamate and substance P
- Spinal neuron post synaptic membrane
- NMDA
- Opioids
- alpha adrenergic
- GABA
- Ca2+
15
Q
Spinal Opioids
A
- Morphine
- HM
- fentanyl
- delivered directly to opioid receptors in dorsal horn of spinal grey matter
- opioid receptors are in peripheral afferents and post synaptic second order neurons
- opioids inhibit synaptic transmission between primary afferent and second order neurons
