Anesthetics

Question 1

Types of anesthetics

Answer 1

inhaled, parenteral, local

Question 2

Two important properties that drive onset, extent and duration

Answer 2

lipid solubility (determines potency, protein binding and DOA), Ionization constant

Question 3

General anesthesia should always include

Answer 3

sleep induction, loss of pain responses, amnesia, skeletal muscle relaxation, loss of reflexes

Question 4

Inhaled anesthetics

Answer 4

Ether, Nitrous oxide, Haltothane (Fluothane), Enflurane (Ethrane), Desflurane (Suprane), Isoflurane, Sevoflurane (Ultane)

Question 5

Inhaled anesthetic MOA

Answer 5

activate K channels, block Na channels to increase cellular threshold for firing, decreases neuronal activity

Question 6

Inhaled anesthetic ADRs

Answer 6

increases ICP, post op N/V, malignant hyperthermia: tachy, HTN, hyperkalemia, muscle rigidity, associated with sudden and massive release of Ca

Question 7

What is used to treat malignant hyperthermia

Answer 7

dantrolene and fluids

Question 8

Parenteral anesthetics

Answer 8

Ketamine, Etomidate (Amidate), Proprofol (Diprivan), short acting barbituates (sodium pentothal), benzodiazepines

Question 9

Katamine is mostly used

Answer 9

in animals and some in dental procedures

Question 10

Etomidate (Amidate) is used for

Answer 10

short term sedation (10 min)

Question 11

Proprofol (Diprivan) is used

Answer 11

regularly in hospt setting for procedures and continuous infusions in ICUs

Question 12

Parenteral anesthetics can also be used for

Answer 12

signal conduction alteration (arrhythmias)

Question 13

Parenteral anesthetic MOA can make them dangerous

Answer 13

if inadvertently given IV when intended to be given locally

Question 14

Local anesthetics MOA

Answer 14

blockade of voltage gated Na channels in a manner that is use-dependent, oftentimes given with a agonist such as epi with goal of vasoconstriction of microvascular to reduce blood flow to area and minimize wash out

Question 15

Local anesthetic can be given with

Answer 15

dexamethasone (corticosteroid) with the thought that it will increase duration by 50%

Question 16

How can local anesthetic toxicities be reversed

Answer 16

with use of IV lipid to remove anesthetic from sight of action

Question 17

Effects of local anesthetics

Answer 17

Nerves- dec conduction, vascular smooth muscle- vasodilation, heart- decrease excitability, reduce pacemaker activity, prolong ERP up to and including death in severe toxicity, CNS-increased excitability

Question 18

Local anesthesthics tend to affect

Answer 18

small myelinated neurons 1st, at higher concentration, they will block signal transduction through myelinated neurons

Question 19

The more lipophillic the anesthetic the…

Answer 19

more potent w/ faster onset

Question 20

Order of local anesthetic blockade

Answer 20

pain, sensation of temperature, touch/pressure, motor function, reversal/recovery is the opposite

Question 21

Classes of local anesthetics

Answer 21

Esthers- Procaine (Novocaine), tetracaine (pontocaine), Benzocaine; Amides- Lidocaine (Xylocaine), mepivacaine (Carbocaine), Bupivacaine (marcaine), Ropivacaine (Naropin)

Question 22

Topical administration

Answer 22

Benzocaine*** (only indication), Lidocaine, Tetracaine, used for diagnostic, procedures

Question 23

Infiltration administration

Answer 23

lidocaine, procaine, bupivacaine, local application, injection

Question 24

Nerve block administration

Answer 24

Bupivacaine, ropivacaine, drug is injected or catheter inserted for infusion to cluster of neurons (femoral, sciatic)

Question 25

Epidural administration

Answer 25

burivacaine, ropivacaine, injected directly into CSF, usually childbirth or abnormal surgeries, allows for complete blockade of large # of neurons

Question 26

Local anesthetic ADRs

Answer 26

CNS- sedation, restlessness, nystagmus, convulsions, CV- cardiac block, hypotension, arrythmias, vasodilation, allergic rxns- more common with esthers

Question 27

Local anesthetic toxicity

Answer 27

mostly related to inadvertent IV infusion via INTRAVASCULAR catheter or inadvertant IV injection, always aspirate before injecting to confirm placement; HTN, tachy, excitability

Question 28

Lidocaine

Answer 28

dental anesthesia, available as 1%, 2% in combo w/ epi, keep perservatives in mind, dose needed depends on area and duration needed, usually 2 hrs

Question 29

Bupivacaine (marcaine), Ropivacaine (Naropin)

Answer 29

most common for epidural or nerve blocks post op (femoral or sciatic), different anesthesia providers will use different concentrations, opioids added w/ epidurals

Question 30

Long lasting local anesthetics

Answer 30

Tetracaine (Pontocaine), Bupivacaine (Marcaine), Ropivacaine (Naropin)