Original General and Local Anesthetics

Question 1

sodium thiopental

Answer 1

• barbiturate
• GABA activator
• induction only
• long half-life = hang-over
• can be administered to pediatric patients rectally
• side effects: reduced cerebral blood flow and ICP, venodilation, respiratory depression
• not contraindicated in patients with coronary artery disease, no arrhythmogenic effects

Question 2

propofol

Answer 2

• GABA activator
• induction and maintenance
• antiemetic
• short half-life = good for outpatient surgery
• side effects: pain on injection, more severe blood pressure decrease than thiopental, blunts baroreceptor reflexes, more respiratory depression than thiopental

Question 3

etomidate

Answer 3

• only for patients at risk for hypotension
• induction only
• side effects: does not decrease BP, less respiratory depression than thiopental, but more nausea and vomiting and suppression of adrenocortical stress response

Question 4

ketamine

Answer 4

• “dissociative anesthesia” = profound analgesia, unresponsiveness to commands even though eyes open, amnesia, spontaneous respiration
• NMDA antagonist
• very little respiratory depression, bronchodilator
• side effects: nystagmus, lacrimation, salivation, increased ICP, emergence delirium, hypertension
• reserved for patients with bronchospasm or children undergoing short, painful procedures

Question 5

midazolam

Answer 5

• short-acting benzodiazepine
• conscious sedation
• anxiolytic
• induction only
• side effects: respiratory depression/arrest
• contraindications: neuromuscular disease, Parkinson’s, bipolar disorder

Question 6

isoflurane

Answer 6

• moderate blood:gas partition coefficient
• induction and maintenance
• airway irritant
• decreases BP
• arrhythmias (sensitizes heart to catecholamines)
• increases ICP

Question 7

desflurane

Answer 7

• very low blood:gas partition coefficient
• maintenance only
• not used to induce because of respiratory irritation
• bronchospasm

Question 8

sevoflurane

Answer 8

• very low blood:gas partition coefficient
• 5% metabolized to fluoride in liver –> renal damage
• induction and maintenance
• NOT respiratory irritant
• less respiratory depression than isoflurane

Question 9

nitrous oxide

Answer 9

• concentrates gases that are administered with it
• adjunct with other inhalational anesthetics
• may dilute oxygen when discontinued, need to place patients on 100% O2 during emergence

Question 10

mechanism of local anesthetics

Answer 10

bind reversibly to a site within the pore of sodium channels in nerves, thus blocking ion movement

Question 11

cocaine

Answer 11

• ester local anesthetic
• potent vasoconstrictor
• topical for upper respiratory tract (shrinks mucosal membranes and limits bleeding)

Question 12

procaine

Answer 12

• short-acting ester local anesthetic
• infiltration anesthesia
• low potency, slow onset, short duration of action

Question 13

tetracaine

Answer 13

• long-acting ester local anesthetic
• more potent and longer duration of action than procaine
• spinal, topical, opthalmic
• not used for peripheral nerve block

Question 14

benzocaine

Answer 14

• ester local anesthetic
• low solubility in water
• topical for wounds and ulcerated surfaces

Question 15

lidocaine

Answer 15

• amide local anesthetic
• faster, more intense, long-lasting than procaine
• used with vasoconstrictors to decrease toxicity

Question 16

bupivacaine

Answer 16

• long-acting amide local anesthetic
• long duration of action
• motor-sparing
• cardiotoxic

Question 17

ropivacaine

Answer 17

• long-acting amide local anesthetic
• less cardiotoxic than bupivacaine
• even more motor-sparing than bupivacaine