Test 2 General Anesthetics

Question 1

Halothane

Answer 1

Medium rate of onset and emergence.

Halothane is pleasant-smelling and nonirritating to the respiratory tract. It is almost never used today because of its sensitization to catecholamines and its potential to cause liver necrosis.

Question 2

Desflurane

Answer 2

Most rapid induction and emergence (even after long surgery increased HR and BP (problematic for cranial injuries)

Respiratory depression. Pungent, so not good for induction.

Potentiates neuromuscular blockers

Question 3

Sevoflurane

Answer 3

Rapid onset and recovery (low blood solubility) so good for outpatient procedures.

Unstable in soda-lime

Pleasant smelling so can be used for induction, esp in pediatric patients.

No CV potentiation so good for elderly.

Respiratory depression, neuromuscular potentiation.

Question 4

Isoflurane

Answer 4

Medium rate of onset and recovery (even after long procedures)

Pungent so not often used for induction.

Potentiates actions of neuromuscular blockers, maintains CO, does not raise ICP

Respiratory depression

Question 5

Enflurane

Answer 5

Medium rate of onset and recovery

Question 6

Nitrous Oxide

Answer 6

Supplement to other anesthesias. When used in conjunction, allows more rapid awakening and a reduction in CV side effects.

Rapid induction and emergence.

Question 7

Propofol

Answer 7

IV

Induction, maintenance, sedation (OR and ICU)

IPSP by affecting the GABAa receptors

CNS - decreases CMRO2 (“cerebral metabolic rate of oxygen”) and intra-cranial pressure

Veno- and arterio- dilator (reduced pre-load and afterload, so decreases BP)

Respiratory depression –> apnea

Question 8

Thiopental

Answer 8

Barbiturate - GABA receptors

Most used induction drug until propofol (no longer even available in US)

Arterial vasoconstrictor (if in artery –> limb ischemia)

Puts the brain to sleep (vasoconstrictor and decreases CMRO2)

Question 9

Ketamine

Answer 9

NMDA (“N-methyl-D-aspartate”) receptor antagonist

Dissociative anesthesia (patient looks awake, but isn’t)

Induction and short procedures, IV for pain

Keep breathing, bronchodilator

Increases CMRO2, cerebral blood flow, and intracranial pressure.

Increases BP and HR (good for trauma)

Bad dreams, hallucinations, salivation, twitchy

Question 10

Etomidate

Answer 10

GABA

Least cardiovascular side effects

Vasoconstrictor and decreases CMRO2

Adrenal suppression (decreased NE, therefore decreased stress response, so can’t respond to decreased BP if given multiple doses or infusion)