General Anesthetics

Question 1

Halothane

Answer 1

• volatile anesthetic
• potent with ~rapid induction and emergence
• requires an additional analgesic
• causes a dose dependent depression of the myocardium and reduces venous tone=== decr CO and BP
• causes bradycardia and incr ICP
• causes bronchodilation while also decreasing tidal volume
• doesn’t cause neuromuscular blockade but potentiates their effectss
• sensitizes catecholamines and can cause liver necrosis

Question 2

Isoflurane

Answer 2

• volatile anesthetic
• less soluble
• potent ventilatory depressor
• maintains CO by dilating vessels to decr afterload
• doesn’t raise ICP
• potentiates the effects of neuromuscular blockers

Question 3

sevoflurane

Answer 3

• volatile anesthetic
• low solubility in blood
• potent ventilatory depressor
• maintains CO by dilating vessels to decr afterload
• doesn’t raise ICP
• potentiates the effects of neuromuscular blockers (so need less of them)
• used for pediatrics because it smells good

Question 4

desflurane

Answer 4

• volatile anesthetic
• lowest solubility
• causes symp activation == incr HR and BP (and ICP)
• potent ventilatory depressor but it’s a respiratory irritant
• potentiates effect of neuromuscular blockers

Question 5

Nitrous Oxide

Answer 5

• gaseous anesthetic
• incapable of independently producing surgical anesthesia outside of a hyperbaric chamber
• low solubility= rapid emergence and induction
• good analgesic (laughing gas = excitement)
• doesn’t sensitize to catecholamines and doesn’t raise ICP
• not a respiratory irritant

Question 6

thiopental

Answer 6

• barbituate
• very lipid soluble and diffuse rapidly across mbs like BBB
• initially has high flow to brain and then decr as other tissues take it from blood and it is metabolized
• bad analgesics
• depresses respiration
• not a respiratory irritant but can cause coughing etc
• decreases ICP
• causes myocardial depression and venodilation (decr BP and CO)
• can cross to the placenta and depress the fetus

Question 7

methohexital

Answer 7

• barbituate

- reduces seizure theshold and is only useful in ECT or epileptic cerebral mapping

Question 8

ketamine

Answer 8

• state of unconciousness is trance-like, cataleptic, and dissociative for the pt
• incr HR and BP
• can use intramuscular route
• causes hallucinations upon waking

Question 9

etomidate

Answer 9

• potent hypnotic agent only used for induction
• advantages- preserves cardiorespiratory stability
• disadvantages - pain on injection, myoclonus, and suppresses adrenocortical function in some pts

Question 10

propofol

Answer 10

• fast induction and faster emergence with little post-op confusion
• vasodilation causes decr BP
• causes respiratory depression

Question 11

opiod analgesics with anesthesia

Answer 11

• morphine and fetanyl
• cause respiratory depression, some decr in BP, some delay in awakening, and some post-op nausea and vomiting
• fetanyl is better than morphine b/c less heart effects