General Anesthesia, MAC Flashcards
What do the letters in MAC stand for, and what is the definition of MAC?
the minimum alveolar concentration of inhaled anesthetics at 1 atm that produces immobility in response to a noxious stimulus in 50% of subjects
What is the dose for MAC awake and what does it mean?
0.5 MAC
the end-tidal anesthetic concentration at 1 atm that suppresses the appropriate response to command in 50% of subjects
What is the dose for MAC amnesia?
0.25 MAC
What is the dose of MAC EI?
1.3 MAC
produces loss of motor function, sensory recall, sympathetic response to stimulation
What is the dose of MAC BAR?
1.5 MAC
adrenergic and CV responses blocked at this dose
Stage III of anesthesia has how many planes?
4
Describe the first plane of stage III.
- considered “light” for surgical anesthesia
- blink and swallow reflexes intact
- regular respiration with good chest motion
Describe the second plane of stage III.
- loss of blink reflex
- pupils become fixed in one position (usually central)
- respirations still regular with good use of accessary muscles
Describe the third plane of stage III.
- start to lose the use of accessary muscles for respiration
- breathing becomes shallow
- may require assisted ventilation
Describe the fourth plane of stage III.
- no use of accessary muscles for breathing
- all respiratory effort produced by the diaphragm
What is the MAC of halothane, isoflurane, desflurane, sevoflurane, and nitrous oxide? (approximately)
halothane - 0.75 isoflurane - 1.2 desflurane - 6 sevoflurane - 2 nitrous oxide - 105
Define diffusion hypoxia.
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)
During flight school, pilots are told that their job will be likened to that of what other profession?
nurse anesthesia
The stage of analgesia or induction is considered what Stage of Anesthesia?
Stage I
The stage of excitement is considered what Stage of Anesthesia?
Stage II