Pain Medicine Flashcards
Where do A-beta, C, and A-delta fibers terminate?
A-beta: spinal cord dorsal horn laminae III-V;
C-fibers: I and II;
A-delta: I, III-V
A-beta, A-delta, and C fibers velocity?
30-60 m/s;
10-15 m/s;
Less than 1.5 m/s
Where are the wide dynamic range neurons located and where do they receive input from?
In laminae III-V;
low threshold A-beta, nociceptive A-delta, and C fibers
What is pKa?
pH at which 50% of drug is ionized
Metabolites of oxycodone? Key metabolite of hydrocodone? Metabolites of codeine?
Oxymorphone and hydrocodone;
Hydromorphone;
Hydrocodone and morphine
Key mixed opioid agonist-antagonist?
Buprenorphine
SE’s of opioids?
Respiratory sedation, cough suppression, constipation, sexual dysfunction
Most COX-2 selective medications among NSAIDs?
Mobic, celebrex
Name a few drug classes you shouldn’t give SSRI/SNRI’s with
TCA’s, MAOI’s, tramadol, some anti-emetics
What channel does gabapentin act on?
Alpha-2-delta subunit of L-type CALCIUM channels
Idea behind neurovascular theory for migraines?
Release of peptide neurotransmitters (Substance P, neurokinin A, calcitonin gene-related peptide) that vasodilate blood vessels causing extravasation of plasma which stimulates trigem nerve endings
Most common headache type?
Tension-type headaches
Nerve responsible for post-mastectomy pain?
Intercostobrachial neuralgia (T1-T2)
Lung cancer can cause what issue with tubular bones?
Hypertrophic pulmonary osteoarthropathy; get clubbing and periosteal proliferation of the tubular bones, leading to painful arthropathy in ankles, knees, wrists, elbows (KAWE)
Some high-yield neuroablative techniques for cancer pain?
Dorsal root entry zone (DREZ) lesioning: selectively destroys neurons located in posterolateral spinal cord;
Cordotomy: selectively ablates spinothalamic tract; good for cancer pain refractory to level 3 treatment on WHO ladder
What is pathology of interstitial cystitis? First line treatment?
Chronic inflamm conditions of bladder’s submucosal and muscular layers;
patient education, diet modification, stress management
What does the medial branch innervate?
Facet joint, multifidus muscle, interspinal ligament and muscle, and periosteum of neural arch
What are intervertebral discs innervated by?
Posteriorly by sinuvertebral nerves, laterally by ventral rami, anterolaterally by gray rami communicans
Modic classifications of subchondral marrow for MRI:
- Bright on T2, dark on T1 (edema)
- Bright on T2 and T1 (fat)
- Dark on T2 and T1 (bony sclerosis)
Bright, dark
B, B
D, D
Of the local anesthetics, list them by longest duration of action: bupivicaine, lidocaine, ropivacaine, procaine
Bupivicaine equal to ropivacaine more than lidocaine more than procaine
What are the particulate steroids vs the non-particulate steroid?
Particulate: betamethasone, methyprednisolone, triamcinolone;
Non-particulate: dexamethasone
For neurolysis, which of alcohol and phenol is hypo/hyperbaric relative to CSF?
Alcohol: hypobaric;
phenol: hyperbaric
“E” in phenol and hyperbaric
Local anesthetic toxicity symps?
Early: Peri-oral and tongue paresthesias; dizziness, orthostasis;
Late: Muscle twitch, drowsiness, CNS depression, resp depression, tonic-clonic seizures, bradycardia, hypotension, cardiac arrhythmia, cards arrest
Borders of the safe triangle are
- Superior border: horizontal line parallel to inferior border of pedicle
- Lateral border: lateral edge of vertebral body
- Hypotenuse: Spinal nerve root
