General Anesthesia, MAC

Question 1

What do the letters in MAC stand for, and what is the definition of MAC?

Answer 1

the minimum alveolar concentration of inhaled anesthetics at 1 atm that produces immobility in response to a noxious stimulus in 50% of subjects

Question 2

What is the dose for MAC awake and what does it mean?

Answer 2

0.5 MAC

the end-tidal anesthetic concentration at 1 atm that suppresses the appropriate response to command in 50% of subjects

Question 3

What is the dose for MAC amnesia?

Answer 3

0.25 MAC

Question 4

What is the dose of MAC EI?

Answer 4

1.3 MAC

produces loss of motor function, sensory recall, sympathetic response to stimulation

Question 5

What is the dose of MAC BAR?

Answer 5

1.5 MAC

adrenergic and CV responses blocked at this dose

Question 6

Stage III of anesthesia has how many planes?

Answer 6

4

Question 7

Describe the first plane of stage III.

Answer 7

• considered “light” for surgical anesthesia
• blink and swallow reflexes intact
• regular respiration with good chest motion

Question 8

Describe the second plane of stage III.

Answer 8

• loss of blink reflex
• pupils become fixed in one position (usually central)
• respirations still regular with good use of accessary muscles

Question 9

Describe the third plane of stage III.

Answer 9

• start to lose the use of accessary muscles for respiration
• breathing becomes shallow
• may require assisted ventilation

Question 10

Describe the fourth plane of stage III.

Answer 10

• no use of accessary muscles for breathing

- all respiratory effort produced by the diaphragm

Question 11

What is the MAC of halothane, isoflurane, desflurane, sevoflurane, and nitrous oxide? (approximately)

Answer 11

halothane - 0.75
isoflurane - 1.2
desflurane - 6
sevoflurane - 2
nitrous oxide - 105

Question 12

Define diffusion hypoxia.

Answer 12

Diffusion hypoxia refers to the rapid diffusion of nitrous oxide into alveoli at the end of a nitrous oxide anesthetic. Nitrous oxide dilutes the alveolar gas and produces a transient decrease in Pao2 and Paco2. (Miller’s Anesthesia)

Question 13

During flight school, pilots are told that their job will be likened to that of what other profession?

Answer 13

nurse anesthesia

Question 14

The stage of analgesia or induction is considered what Stage of Anesthesia?

Answer 14

Stage I

Question 15

The stage of excitement is considered what Stage of Anesthesia?

Answer 15

Stage II

Question 16

The surgical or operative stage is considered what Stage of Anesthesia?

Answer 16

Stage III

Question 17

The “danger stage” is considered what Stage of Anesthesia?

Answer 17

Stage IV

Question 18

When preparing for a case, acronyms like MSMAID, SOAP, and DAMMITTS are used as reminders…. pick one and decipher its meaning!

Answer 18

MSMAID - machine check, suction, monitors, airway, IV setup, drugs

SOAP - suction, oxygen, airway, pharmacology

DAMMITTS - drugs, airway, machine check, monitors, IV setup, twitch monitor, table, and stethoscope

Question 19

What are the 5 goals of the perioperative period?

Answer 19

• amnesia
• analgesia
• immobility
• unconsciousness
• attenuation of autonomic reflexes

Question 20

What is the ASA classification of a healthy patient?

Answer 20

ASA I

Question 21

What is the ASA classification of a patient with mild systemic disease without functional limitations?

Answer 21

ASA II

Question 22

What is the ASA classification of a patient with severe systemic disease with definite functional limitations?

Answer 22

ASA III

Question 23

What is the ASA classification of a patient with severe systemic disease that is life threatening?

Answer 23

ASA IV

Question 24

What is the ASA classification of a dying patient not expected to survive for 24 hours without an operation?

Answer 24

ASA V