Ch 11 - Pain Management: Interventional procedures Flashcards
What form of radiation comes from x-ray?
Electromagnetic, ionizing radiation
What are the adverse effects of radiation exposure?
Carcinogenesis
Radiation burns
Cataract formation
How can you minimize practitioner radiation exposure?
Lead apron
Thyroid shield
Lead glasses
Keep extremities far from fluoro machine
What can be used to monitor cumulative radiation exposure?
Film badge dosimeter worn outside of the lead protection should be utilized to monitor cumulative radiation exposure
How can you minimize patient radiation exposure?
X-ray tube far away from patient so larger area exposed to smaller radiation
Image intensifer close to patient to optimize image quality and minimize scatter radiation
Collimation (narrow x-ray beam) reduces direct and scatter radiation
Pulse mode rather than continuous exposure
What is the MOA of local anesthetics?
Reversibly blocking the sodium channels in nerve and muscle membranes
What signs of CNS toxicity from local anesthetic?
Mild—Lightheadedness/dizziness Perioral numbness Blurred vision Tinnitus Tremors Shivering Severe—tonic-clonic seizures, respiratory depression/arrest
What signs of Cardiac toxicity from local anesthetic?
Arrhythmias (conduction blocks, ventricular dysrhythmias)
Myocardial depression
When local anesthetics are injected into the subarachnoid space, what is effected first?
Sympathetic nerves first (motor nerves last)
What can Intravascular anesthetic injection of local anesthetic cause?
Adverse cardiovascular effects
What is the recommended max dose of Bupivacaine (without Epi)?
2.5 mg/kg, not to exceed 175 mg
What is the recommended max dose of Lidocaine (without Epi)?
4.5 mg/kg, not to exceed 300 mg
What is the recommended max dose of Ropivacaine?
5 mg, not to exceed 200 mg
What is the recommended max dose of Procaine?
7 mg/kg, not to exceed 350–600 mg
What is the MOA of decreasing pain with corticosteroids?
Cause direct inhibition of C-fiber neuronal membrane excitation and induce synthesis of a phospholipase A2 inhibitor, thereby preventing release of substrate for prostaglandin synthesis.
Which steroids have no mineralocorticoid activity?
Dexamethasone
methylprednisolone
triamcinolone
betamethasone
Which steroids can increase blood glucose with glucocorticoid activity?
dexamethasone and betamethasone
Which steroid is non-particulate?
Dexamethasone sodium phosphate
What can happen with intravascular injection of particulate steroid?
Embolic infarction of the spinal cord and brain
How can urticaria after spine injection be treated?
Benadryl
Vistaril
Cimetedine
Ranitidine
How can facial and laryngeal edema after spine injection be treated?
Epinephrine
IVF for hypotension
ACLS protocol
How can bronchospasm after spine injection be treated?
Oxygen
Beta-agonist inhalers
Epinephrine
IVF for hypotension
How can hypotension with tachycardia after spine injection be treated?
Reverse Tendelenburg
IVF
Epinephrine
How can hypotension with bradycardia after spine injection be treated?
Reverse Tendelenburg
IVF
Atropine
How can severe HTN after spine injection be treated?
Nitroglycerin
Phentolamine in pheochromocytoma
How can seizures after spine injection be treated?
Secure airway Oxygen Diazepam or midazolam Phenytoin ACLS protocol
How can pulmonary edema after spine injection be treated?
Oxygen
Diuretics
Consider IV morphine use
Transfer to ICU
What are early symptoms of early local anesthetic toxicity?
Perioral and tongue paresthesias
Dizziness
Orthostasis
What are early symptoms of early local anesthetic toxicity?
Muscle twitching Drowsiness CNS depression Respiratory depression Tonic-clonic seizures Bradycardia Hypotension Cardiac arrhythmia (conduction block) Cardiac arrest
How is local anesthetic toxicity treated?
ACLS protocol
Cardiac arrhythmia treatment
Lipid emulsion therapy
What are side effects of corticosteroids from spine injection?
HA Insomnia Facial erythema rash Pruritus Dizziness Low grade fever Transient hyperglycemia HTN
When are epidural steroid injections indicated?
Cervical or lumbar radicular symptoms with correlation on MRI/CT and/or EMG
What is the infrapedicular or “safe triangle” approach for lumbar transforaminal ESI?
Endpoint for needle is inferior to the 6 o’clock position of the pedicle in the upper 1/3 of the neuroforamen
What are the borders of the “safe triangle” in lumbar TF ESI?
Superior base: line parallel to inferior border of the pedicle
Height: lateral edge of vertebral body
Hypotenuse: spinal nerve root
What are the borders of the Kambin’s triangle?
Inferior Base: caudal vertebral body
Height: traversing nerve root
Hypotenuse: exiting nerve
What is the approach for an interlaminar injection?
Midline or paramedian approach
What type of needle is used for an interlaminar injection?
18-or 20-gauge Tuohy or Crawford needle connected to a loss of resistance (LOR) syringe
What are the ligaments that are passed through for an interlaminar injection?
supraspinous ligament → interspinous ligament →
ligamentum flavum
Where is the needle advanced for a caudal injection?
Sacral hiatus
Why should the needle not be advanced higher than the S3 level during a caudal injection?
Dural sac typically ends at the S2 level
What levels can be treated with a cadual injection?
Superiorly up to the L4–L5 or L5–S1 levels
What is considered a positive response for medial branch block (MBB)?
> 80% pain relief post-procedure
Where is the needle aimed during a cervical MBB?
Articular pillars of the vertebra
Where is the needle aimed during a lumbar MBB?
Groove b/w the superior articular process and transverse process (where the medial branch lies)
How should the needle tip be positioned in conventional RFA ablation?
Parallel to the target medial branch nerve to produce optimal nerve lesioning
What are complications of RFA?
Spinal nerve lesioning (causing paralysis, neuropathic pain) Increased pain Vasovagal reaction Bruising Ataxia (lesion to third occipital nerve) Neuritis Dropped head syndrome Infection Bleeding
What type of joint is the sacroiliac joint?
Diarthrodial joint
Where is the needle directed in an SI joint injection?
Inferior border of the joint at a point where the anterior and posterior joint lines overlap
What is a Discography?
Diagnostic procedure in which a spinal disc is pressurized to establish or rule out a diagnosis of discogenic pain
Where is the needle advanced in Discography?
Anterior to the superior articular process of the inferior vertebral body and advanced slightly into the disc
What technique can be used to decrease risk of infection in Discography?
Double needle technique
Pre-procedure IV
Intradiscal antibiotics
What are the risks of Discography?
Infection (diskitis, osteomyelitis, abscess)
Accelerated disc degeneration
False positive results
Increased pain
What information should be gathered regarding pain response in Discography?
Pain Level
Character
Location
What is a normal opening disc pressure?
5-25 psi
What does a disc manometry of >30 psi indicate?
Needle tip is in annulus fibrosis
What does a disc manometry of >50 psi indicate?
Excessive pressure can result in false positive results
Disc annulus sensitivity in chemical discs is indicated by pain at what psi?
Concordant pain response at 15 psi above opening
pressure
Disc annulus sensitivity in mechanical discs is indicated by pain at what psi?
Concordant pain response at 15 to 50 psi above
opening pressure
Disc annulus sensitivity in indeterminate discs is indicated by pain at what psi?
Pain provocation at 51 to 90 psi above opening pressure (should not be considered clinically significant)
Disc annulus sensitivity in normal discs is indicated by pain at what psi?
No pain provocation
Where do Presynaptic sympathetic fibers arise?
Intermediolateral cell column horn of the spinal cord from T1–L2 levels and leave the CNS via the ventral roots
Where do post-ganglionic axons travel?
Unmyelinated and leave the paravertebral ganglia via the gray rami communicantes and exit via the segmental spinal nerves
What is the stellate ganglion compromised of?
Lower cervical sympathetic and upper thoracic ganglia
Where is the stellate ganglion located?
Anterolateral to the C7 vertebral body
Where does the stellate ganglion receive parasympathetic input and transmits sympathetic output to?
head, neck, heart, and upper extremities
What is the clinical landmark for injection target for stellate ganglion block?
Chassaignac tubercle (carotid tubercle) of the C6 vertebral body
What anatomic abnormality lead to an incomplete stellate ganglion sympathetic blockade?
Anomalous intrathoracic pathways known as Kuntz’s nerves can bypass the stellate ganglion
What are indications for stellate ganglion blocks?
Chronic facial and/or cervicobrachial pain syndromes
CRPS type I or II
Vascular and sympathetically-mediated HAs
Vascular insufficiency/vaso-occlusive diseases
Neuropathic pain syndrome
Post-herpetic neuralgia, Trigeminal neuralgia
Neuropathic orofacial pain
Phantom limb pain
Hyperhidrosis
What are complications of stellate ganglion blocks?
Ipsilateral Horner’s syndrome Hoarseness Paralysis Dyspnea intravascular/intrathecal: seizures and cardiac arrhythmias Infection Hematoma Local organ injury
How many pairs of thoracic sympathetic ganglia are there?
10 (sometimes 11)
What is the innervation of the cardiac plexus?
T1-4
What is the innervation of the celiac ganglion?
T5-T12
What does the aortic plexus provide innervation to?
lower abdominal viscera
Celiac plexus receives sympathetic and parasympathetic fibers from which nerves?
SNS: greater, lesser and least splanchnic nerves
PNS: vagus nerve
What are indications for celiac plexus block?
Sympathetically mediated thoracic, chest wall, upper abdominal viscera pain Hyperhidrosis Intractable cardiac arrhythmia Prinzmetal’s angina Raynaud’s disease Upper extremity CRPS Post-thoracotomy pain Acute herpes zoster Post-herpetic neuralgia Post-mastectomy phantom breast pain
What are complications of celiac plexus block?
ipsilateral Horner’s syndrome
Pneumothorax
Infection
Temporary intercostal neuritis
What are indications for Superior Hypogastric plexus block?
Chronic pelvic pain from gynecologic, colorectal, or
genitourinary cancer
Where is the Superior Hypogastric plexus located?
Lower 1/3 of the L5 vertebral body in from the anterolateral border of L5 bilaterally
What are the landmarks for Superior hypogastric plexus block?
L4 and L5 spinous processes are identified and needle insertion sites are 5 to 7 cm lateral to the midline at the level of L4–L5 interspace
What indicates proper needle depth in the lateral view during Superior hypogastric plexus block?
Smooth posterior contour corresponding to the anterior psoas fascia
Where do sacral nerves provide innervation to?
Sensation: anorectal region
Motor: external anal sphincter and levator ani muscles
What visceral innervation does S1-S4 provide?
Bladder
Urethra
External genitalia
How do spinal cord stimulators (SCS) utilize the Gate Control Theory?
Introducing external neuromodulation in the form of non-painful electrical signals from percutaneous electrodes placed over the dorsal columns
How is SCS stimulation increased?
Amplitude
Frequency
Pulse width
Supine position
What are indications for SCS?
Failed back surgery syndrome Discogenic pain refractory to conservative and surgery CRPS Arachnoiditis Painful peripheral neuropathy Refractory angina pectoris Non-operable ischemic pain Migraine HA
Where are SCS electrodes inserted?
Cervical: Below T1-T2 vertebral body
Lower body: T12-L1 or L1-2
Upper extremity: T2-3 or T3-4
Where should SCS electrodes be placed to maximize electrode stability?
2 segments below target so 3 inch of lead body lies within epidural space
Which patients are considered candidates for implanted drug delivery system device?
Chronic intractable pain with known pathophysiology who failed maximal medical and/or surgical therapy
What are requirements prior to implanted drug delivery system device placement?
Patient sensitive to infused agent
Favorable Psychological evaluation
Life expectancy >3 months
What are routes of administration of implanted drug delivery system device?
Intrathecal vs epidural
What are disadvantages of intracthecal route for implanted drug delivery?
HA
Neural injury
Supraspinal spread
What are advantages of intracthecal route for implanted drug delivery?
Requires lower dosage
Less systemic effect
No catheter tip dural fibrosis
What are complications of implanted drug delivery system device placement?
Infection Skin erosion from hardware Pump failure Catheter kinking, migration and obstruction Catheter tip granuloma formation
