local anesthetics

Question 1

cocaine

Answer 1

• ester
• provides vasoconstriction with topical use
• easily absorbed from mucous mbs so incr likelihood of systemic toxicity
• blocks reuptake of NE so can cause hypertension and tachycardia
• potency= 2
• duration of action = medium
• rapid onset

Question 2

procaine

Answer 2

• ester
• readily hydrolyzed by plasma cholinesterase so short duration of action
• potency = 1
• onset = slower
• uses= infiltration, nerve block, and subarachnoid

Question 3

tetracaine

Answer 3

• ester
• spinal anesthetic (low dose)
• more lipophilic so more potent, long-lasting, and more toxic
• potency = 16
• slow onset for spinal
• use = subarachnoid

Question 4

lidocaine

Answer 4

• amide
• common local anesthetic because it is fast acting, more intense, medium lasting, and more extensive
• potency =4
• use = infiltration, nerve block, IV, regional, epidural, and subarachnoid

Question 5

mepivacaine

Answer 5

• amide
• medium duration of action and more rapid onset of action than lidocaine
• was widely used in OB but now shown to affect the neonate
• potency =2
• use = infiltration, nerve block, and epidural

Question 6

bupivacaine

Answer 6

• amide
• very prolonged duration of action= good for post-op analgesia
• used as epidural in OB
• more lipophilic= more toxic and potent than other amides (especially cardiotoxicity)
• slow onset
• very potent =16
• infiltration, nerve block, epidural, and subarachnoid

Question 7

ropivacaine

Answer 7

• amide
• compared to bupivacaine: greater margin of safety (less cardiotoxic) and produces less of a motor block
• epidural (OB), infiltration anesthesia, and peripheral nerve block
• slow onset and long duration
• very potent = 16

Question 8

peripheral nerve block

Answer 8

• local anesthetic is deposited within the nerve sheath to block a peripheral nerve or plexus
• block onset proceeds proximal to distal b/c distal fibers = on the interior of the nerve

Question 9

spinal anesthesia

Answer 9

• a block of spinal nerves (autonomic, sensory, and motor) in the subarachnoid space
• inject anesthetic into the CSF from L2-L3 caudad
• blocks all nerves caudad and can be prepared so it will rise and also block nerves rostrally

Question 10

epidural anesthetic

Answer 10

• a block of spinal nerves (autonomic, sensory, and motor) in the epidural space
• can be done at any level of the cord from the cervical region to the sacrum and the drug moves equally caudad and cephalad from the injection level
• resultant block is segmental- so you can preserve ability to move legs

Question 11

benzocaine

Answer 11

• for topical use only

- ester