Intro To Anesthetics

Question 1

3 steps of Pain neurophysioplogy

Answer 1

1) initiation =(receptor activation)
2) propagation =(site to spinal cord to thalamus)
3) perception =(sematosensory, emotional, cognitive brain centers)

Question 2

Local/peripheral anesthetics

Answer 2

• close to source

* Novocaine, Cocaine

Question 3

Central analgesics

Answer 3

• supraspinal + spinal sites

* Morphine, NSAIDS

Question 4

General Anesthetics

Answer 4

• Loss of consciousness

* Propofol, Etomidate, Barbituates)

Question 5

Local anesthetic agents

Rx

Answer 5

• Benzocaine
• Cocaine
• Procaine
• Lidocaine
• Ropivacaine

Question 6

Adjuncts

Rx

Answer 6

• Epi
• Clonididne
• Diazepam

Question 7

Pain receptor on Nociceptor that lets in Na+

Answer 7

TRP Channel

Question 8

How sensitize receptor to more pain?

Answer 8

*Pain (C?) fiber releases substance P, attracts macrophages, release prostaglandins, more pain

Question 9

How pain pathway causes edema?

Answer 9

C fibers release Substance P —> attract mast cells —> release cytokines —> edema

Question 10

A delta pain fibers vs. C fibers

fibers intercept pain stimulus then synapse to…?

Answer 10

A delta =*Neospinothalamic neuron (2nd order neuron)

C =* Paleospinothalamic neurons

Question 11

Myelinationf/Pain type

A delta vs. C pain fibers

Answer 11

A delta = myelinated (First Pain - Sharp)

C = UNmyelinated (Second pain - dull)

Question 12

NSAIDS

MOA

Answer 12

Block COX2 to stop PG production to stop C and A-delta-fiber sensitization

Question 13

LAs + NSAIDS

Block 1st or 2nd pain?

Answer 13

Block 1st + 2nd pain

Question 14

Blocks which activation states of Na channel?

• TTX
• Other LA

Answer 14

• Any state

* ONLY Activated (always) + Inactivated (sometimes) = Use-Dependent Blockade

Question 15

LA structure

What increases Lipophilicity?

Answer 15

• # Carbon chains + length both sides
• Mid-Carbon chain length

= FAST ONSET, UP POTENCY

Question 16

Structure of LA

Amide link

• Prototype
• I’s
• T1/2

Answer 16

• Lidocaine
• 2 I’s
• Long t1/2 = liver metab, unable to cross cell membrane (proton acceptor/weak base)

Question 17

Structure of LA

Ester link

• Prototype
• I’s
• T1/2

Answer 17

• Procaine
• 1 I
• Short t1/2 = plasma + liver metab

MORE LIKELY ALLERGIC RXN

Question 18

LAs block more

• diameter
• myelination
• Fire frequency
• Fiber position

Answer 18

• small diameter
• myelinated>unmyelinated
• Use-dependent
• External fibers blocked more than internal

Question 19

Topical Anesthesia

Rx

Answer 19

• Benzocaine
• Lidocaine

ENT, DENTAL PAIN w/ PROCEDURE

Question 20

Infiltration anesthesia

Rx

Answer 20

• Procaine
• Lidocaine

INJECT SUB-Q, MUC. MEMBRANE

Question 21

Bier block

Rx

Answer 21

*Lidocaine

INJECT ARM W/ TOURNIQUET

Question 22

Peripheral Nerve Block

Rx

Answer 22

• Lidocaine
• Ropivacaine

AROUND NERVE/PLEXUS

Question 23

Epidural Anesthesia

Rx

Answer 23

• Procaine
• Lidocaine

CHILDBIRTH

Question 24

Spinal Anesthesia

Rx

Answer 24

• Procaine
• Lidocaine

PROCEDURES W/ TRUNK

Question 25

What increases Systemic Toxicity Risk with LA? How to reduce?

Answer 25

DENSE VASCULATURE Intercostal> caudal > epidural > brachial plexus > sciatic nerve REDUCE w/ Epi!

Question 26

High LA systemic absorption effects * Brain * Heart

Answer 26

* Brain (Gaba A blockade)= anxiety, confusion, tremor/convulsion (tx= Valium (benzo)) * Cardio = hypoTN, bradycardia (BUT COCAINE = tachycardia, vasoconstriction) =. (Tx= cardio rescuscitation/bypass, IV lipid emulsion

Question 27

Allergies from which LA type?

Answer 27

Esters From PABA

Question 28

Clonidine *MOA

Answer 28

*a2 on C/A-delta fiber (dorsal horn) = lowers pain transmission (less sub P/glutamate)

Question 29

Cocaine

Answer 29

* ester * ENT procedures * ONLY LA = Tachycardia, vasoconstriction

Question 30

Procaine

Answer 30

* 1st synthetic local anesthetic * slow onset, short duration * for Infiltration/Periph Nerve Blocks

Question 31

Lidocaine

Answer 31

MC * Amide * Vasodilation, so combine w/ Epi * Class 1B anti-arrythmic (Na+)

Question 32

Ropivacaine

Answer 32

* S-isomer ONLY = low cardiac Na channel affinity, LOWER CARDIO TOXICITY * R-isomer high cardiac affinity