7.10 (9.8) Interventional approaches for pain Flashcards
What are the two general indications for an interventional approach to pain management?
What are two general goals of an interventional approach to pain management?
indications:
(a) uncontrolled pain despite systemic analgesics
(b) unacceptable systemic analgesic adverse effects
Goals: improve pain control and/or allow opioid dose reduction
A patient has muscle pain and a palpable nodule is felt on examination. What is a trigger point?
What meds can be injection via trigger point injections? Name 3
Besides TP injection, name 3 other interventions that can be done for this patient at the site of their muscle pain
Trigger point: a HYPERIRRITABLE nodule in skeletal muscle that may be palpable, is painful on compression, and can cause characteristic referred pain and/or autonomic phenomena
TP drugs:
- Local anesthetic (lidocaine)
- Botox
- Steroid/NSAID
(ABS)
Treatment options that target trigger point:
- Acupuncture*
- Dry needling*
- Pulse radiofrequency
- Physical manipulation (massage, exercise)*
- TENS
List 2 medications that are generally used with intraarticular injections.
List 3 complications of intraarticular injections
corticosteroids are most commonly used
hyaluronic acid
infection, bleeding, nerve injury, joint destruction
What is the mechanism of action of botulism toxin?
List three clinical situations where it can be used for pain management.
What is the onset of effect post injection and duration?
A patient received botox and had an excellent effect for pain. 3 months later the injection is repeated with no appreciable change in pain. What is the mechanism for this loss of efficacy? What can be done to limit this?
BTX is a neuroparalytic agent produced by the bacterium Clostridium botulinum: irreversibly inhibits acetylcholine release at the neuromuscular junction –> reduce muscle contraction and painful muscle spasm; may also block peripheral sensitization and indirectly reduce central sensitization
BTX is used in spasticity and movement disorders, as an analgesic in migraine, phantom limb pain, complex regional pain syndrome, chronic myofascial pain
Onset 1 week post injection, last 3-4 months
Repeated administration may lead to diminishing benefit due to the development of neutralizing antibodies. An interval of >12 weeks between injections is recommended, and if positive effects are lost, they may be regained by using an alternative formulation.
WP: break into two cards?
List 2 common pain conditions indicating the use of regional (i.e. peripheral) nerve blocks.
What is the main medication generally utilized for these blocks?
A patient has a successful peripheral nerve block and is offered a catheter for ongoing blockage of the nerve. (1) What are three complications that can arise from catheter placement? (2) How long can catheter be maintained for?
perioperative (eg brachial plexus block for upper limb surgery) or chronic pain (diagnostic and therapeutic)
Local anesthetic = main med
complications of long term catheters - infection, local anesthetic toxicity, catheter displacement, or technical difficulties such as catheter knotting
Can be maintained for several weeks
List 3 methods for neurolysis
Radiofrequency (thermal)
Chemical (phenol and ethanol)
Surgical (open)
FS: neurolysis destroys nerves (permanent nerve blocks)
What is the indication for neurolysis?
Severe refractory cancer pain
List three chemicals frequently used for sympathetic nerve blocks
local anesthetic, botox, neurolytic solution (phenol)
FS:
- neurolytic block with phenol = permanent damage of nerve (a type of nerve block)
A patient has a local anesthetic block used to predict the effects of a sympathetic neurolytic block. The trial is a success but after neurolysis there is no pain relief. What might have taken place (two reasons)?
analgesic effect of absorbed local anaesthetic and/or placebo response.
List 5 common sympathetic nerve blocks performed (and their corresponding areas of pain relief)
stellate ganglion block -> upper extremitiy celiac plexus block -> upper abdo pain lumbar sympathetic block -> lower extremity superior hypogastric plexus block -> pelvic pain ganglion impar block -> perineal pain
FS: SC L SG
List four clinical condition for a stellate ganglion block
Angina*
inoperable coronary artery disease
Upper extremity pain: ◆ complex regional pain syndrome* ◆ peripheral vascular disease ◆ Raynaud’s disease ◆ brachial plexus infiltration by tumour* ◆ herpes zoster ◆ phantom pain*
FS:
VIND (PVD, herpes, neoplasm, degenerative = phantom limb)
Celiac plexus block - name
- 2 indications
- 2 approaches
- Side effects (2 common and 2 rare)
Indications:
Visceral pain from -
- pancreatic cancer
- other upper abdominal tumours
Methods:
- percutaneous (fluoroscopy, CT or MRI)
- endoscopic US-guided transoesophageal
Immediate complications:
- diarrhoea
- orthostatic hypotension (usually transient)
Rare:
- paraplegia due to ischaemic spinal cord from injury or spasm of the artery of Adamkiewicz
- seizures
- aortic dissection
SEs = DOPA
List four clinical etiologies that would benefit from a lumbar sympathetic block
Intractable lower extremity pain: (most common indication) ◆ inoperable peripheral vascular disease* ◆ chronic painful leg ulceration ◆ complex regional pain syndrome* ◆ phantom pain* ◆ herpes zoster ◆ diabetic neuropathy*
Kidney pain (including ‘phantom kidney pain’)
Testicular pain
tenesmus
FS
VIND (PVD, herpes, rectal ca = tenesmus, degenerative - phantom pain)
What type of pain might necessitate a superior hypogastric plexus block? List three types of cancer that might cause this type of pain
Pelvic visceral pain
GI (colorectal), GU, Gyne cancer
What type of pain might necessitate a ganglion impar block
Intractable perineal pain
