Pain

Question 1

Chronic opiate therapy can lead to an INCREASE or a DECREASE in cortisol levels?

Answer 1

decrease

can lead to addisonian features like orthostatic hypotension, muscle weakness, hyperpigmentation

really only thing that increases is prolactin

Question 2

what is nociceptive pain?

Answer 2

pain caused by direct damage to tissue - sharp, aching, throbbing

Question 3

first line treatment for post-herpetic neuralgia

Answer 3

TCAs (most useful but anticholinergic side fx), opiates, gabapentin, lyrica

NOT nsaids

can decrease risk of getting PHN with antivirals during acute phase

Question 4

neuropathic pain involves which pathway?

Answer 4

AFFERENT.

Can be peripheral or central

Question 5

nerve fibers are blocked in what order with local anesthetic?

Answer 5

autonomic (smallest diameter), sensory (pain, temperature, touch, pressure), motor

Question 6

difference between amides and esters?

Answer 6

Amides are metabolized in liver. Esters in plasma cholinesterases. More unstable so stabilized with PABA, causing allergies

Question 7

treatment of CPRS I/II?

Answer 7

PT, gabapentin, NMDA antagonists, sympathetic nerve blocks

Question 8

difference between CPRS I and II?

Answer 8

I occurs WITHOUT Injury
II occurs after nerve injury

clinically indistinguishable

Question 9

why does erectile dysfunction occur with lumbar plexus sympathectomy?

Answer 9

reliant on SNS.

also causes hypotension (venous blood pooling 2/2 vasodilation)

Question 10

celiac plexus block complications

Answer 10

diarrhea - supplies sensation to most of bowel. T5-12

Question 11

how is adenosine involved in pain pathways?

Answer 11

believed to be an anti-inflammatory agent

Question 12

what does anesthesia dolorosa result from?

Answer 12

rhizotomy (treatment of trigeminal neuralgia)

Question 13

what is tramadol’s MOA?

Answer 13

SNRI (serotonin and norepi reuptake inhibition) + mu-receptor agonism. Interestingly, SNRI accounts for MORE of painkiller features

Question 14

GABA-A is receptor for what meds

Answer 14

benzos, propofol, etomidate, barbiturates

Question 15

properties of glutamate neurotransmitter

Answer 15

excitatory, interacts with NMDA receptor (which is antagonized by ketamine, methadone, namenda, magnesium, NO)

Question 16

duration of action of neuraxial opiates is related to what?

Answer 16

lipophilicity - the more lipophilic, the more likely to be absorbed systemically

Question 17

why is walking uphill/on an incline and squatting relieve pain for lumbar stenosis?

Answer 17

due to mechanical compression, flexion relieves, extension worsens

Question 18

what is neurogenic claudication?

Answer 18

pain that worsens with exertion or activity (caused by lumbar stenosis)

Question 19

primary inhibitory neurotransmitters in somatosensory system?

Answer 19

Glycine (acts on spinal cord), GABA (acts higher)

Question 20

discogenic pain is worse or better with sitting/bending?

Answer 20

WORSE. improved with standing

worsen with walking down incline

really anything causing flexion

Question 21

tibial nerve is located WHERE to popliteal artery

Answer 21

lateral and superficial

Question 22

number one facter in intrathecal spread

Answer 22

BARICITY (volume, concentration)

hypo and isobaric -> total local anesthetic dose