General Anesthetics

Question 1

What are the 4 stages of anesthesia?

Answer 1

1. Analgesia - also includes amnesia and euphoria
2. Excitement - also includes delerium and combativeness
3. Surgical anesthesia - what you want the pt to be in during operations. Unconscious, regular respiration, decr EOM
4. Medullary depression - decr respiratory and cardiac fxn, no eye mvmt. If your pt is in stage 4 anesthesia, you’re gonna have a bad time.

Question 2

Why does 5’4’’ 325 lb competitive eating champion Cheeseburger Charlie take longer to recover from anesthesia than most patients?

Answer 2

Cheeseburger Charlie has a higher amount of adipose tissue than most other people. Adipose tissue is poorly perfused and has a high partition coefficient, so anesthetic agents are slowly delivered there and tend to aggregate there longer due to their hydrophobicity. Therefore, adipose tissue acts as a reservoir of anesthetics during the recovery phase until it is perfused enough to remove the anesthetic.

Question 3

What would you give a patient who is experiencing preoperative anxiety prior to anesthesia?

Answer 3

Midazolam

Question 4

The most frequently used drug for induction of anesthesia is…

Answer 4

Propofol

Question 5

What are some of the common uses of benzodiazepines?

Answer 5

Perioperative anxiety, short-term sedative hypnotics, anti-seizures, IV anesthesia

Question 6

If a pt OD’s on benzodiazepines, what would you give them?

A. Gabapentin
B. Flumazenil
C. Diazepam
D. Ischial tuberosity spread

Answer 6

B. Flumazenil

Question 7

To induce anesthesia in an elderly patient who has had an MI in the past (therefore decr contractility), what is the best drug to give?

A. Etomidate
B. Phenobarbital
C. Propofol
D. I don’t give a shit

Answer 7

A. Etomidate has less CV and respiratory depression than the other drugs that induce amnesia. Therefore, they are best used in patients w/ compromised cardiac or respiratory fxn. If you picked D, go eat a Snicker’s bar. You’re not you when you’re hungry.

Question 8

Systemic effects of inhaled anesthetics (-ane suffix + nitrous oxide)

Answer 8

All are depressant effects. Decr vascular resistance, decr respiratory fxn, decr brain metabolic rate, uterus relaxation, hepatotoxicity, decr GFR

Question 9

Clinical uses of nitrous oxide are…

Answer 9

…analgesia and sedation in outpt dentistry and as an adjunct to inhaled or IV anesthesia

Question 10

S/e of N2O

Answer 10

Pneumothorax and megaloblastic anemia

Question 11

Clinical uses of halothane

Answer 11

Induction of anesthesia in kids and maintenance of anesthesia in adults

Question 12

After administering halothane, a pt undergoes spastic paralysis and their core body temp incr to over 101 F. What is going on and what should you give the pt?

Answer 12

Malignant hyperthermia. Dantrolene

Question 13

What happens when you give N2O with enflurane?

Answer 13

This decr the minimal anesthetic concentration, so you can give less enflurane and have the same result.

Question 14

Uses for desflurane

Answer 14

Outpt anesthetic

Maintenance of anesthesia

Question 15

S/e of desflurane

Answer 15

Airway irritation, salivation, coughing, bronchospasm, laryngospasm

Question 16

What is so special about thiopental/inhaled anesthetics combinations?

Answer 16

Allows pt to avoid stages 1 and 2 of surgical anesthesia