Med Review Volatiles

Question 1

Volatile gases produce immobility via _______

Answer 1

Volatile gases produce immobility via actions on the spinal cord

enhancing inhibitory channels and attenuating excitatory channels

Question 2

What is a MAC value?

Answer 2

Minimum Alveolar Concentration: concentration at which 50% of patients will not show a motor response to standard surgical incision

Question 3

95% of patients will respond to ___ MAC and 99% will respond to ____ MAC

Answer 3

95% of patients will respond to 1.2 MAC and 99% will respond to 1.3 MAC

Question 4

Which volatile gases would cause the most decrease in BP?

Answer 4

Isoflurane and Desflurane

Question 5

Which volatile would cause the most decrease in tidal volume?

Answer 5

Isoflurane

Question 6

In general, volatiles cause a ____ in cerebral blood flow and thus leads to increased ___?

Answer 6

In general, volatiles cause an increase in cerebral blood flow and thus leads to increased intracranial pressure?

Question 7

Volatiles, in general, cause a ____ in cerebral metabolic rate?

Answer 7

Volatiles, in general, cause a decrease in cerebral metabolic rate?

Question 8

Which volatile has the most affect on renal blood flow, GFR, and UO? What does it do to these?

Answer 8

Isoflurane (forane)
decreases RBF, GFR, and UO

Question 9

Which volatile stinks the most and can cause significant airway irritation?

Answer 9

desflurane (suprane)

Question 10

Which volatile would be good for an obese patient due to its very low solubility, causing quick absorption and going away quickly?

Answer 10

Desflurane (suprane)

Question 11

Which volatile is the least airway irritant and good for pediatric induction but can cause emergence delirium in kids?

Answer 11

Sevoflurane (ultane)

Question 12

Which volatile is linked to nephrotoxicity in rats? Is this significant?

Answer 12

Sevoflurane (ultane)
Not proven to be significant with human use.

Question 13

Which volatile is very lipid soluble and very cheap, leading to ____ emergence? This makes this gas more suitable for?

Answer 13

Isoflurane (forane) is very lipid soluble leading to longer emergence, making it more suitable for longer cases.

or sick patient that is to remain intubated (ICU)

Question 14

Which volatile is used as an adjunct agent and not a solo anesthesia gas?

Answer 14

Nitrous

Question 15

Which volatile provides analgesic effects?

Answer 15

Nitrous

Question 16

Which is the most expensive volatile gas? Which is the cheapest? Intermediate cost?

Answer 16

Des = most expensive
Sevo = intermediate cost
Iso = Cheapest

Question 17

Which volatile is prone to causing N/V, especially at higher doses? What dose?

Answer 17

Nitrous: typically > 0.5MAC = N/V

Question 18

When should you absolutely not use nitrous?

Answer 18

Neuro or bowel cases

Question 19

What factors typically increase anesthetic requirements?

Answer 19

• chronic EtoH
• infants
• red hair
• hypernatremia
• hyperthermia

Question 20

What factors typically decrease anesthetic requirements?

Answer 20

• acute EtoH
• elderly
• hyponatremia
• hypothermia
• anemia
• hypercarbia
• hypoxia
• pregnancy