Inhalent use of Anesthetics

Question 1

3 uses of inhalant anesthetics

Answer 1

• unconsciousness
• immobility
• anti-nociception

Question 2

3 unique properties of inhalants

Answer 2

• administered and eliminated by the lungs
• predictable and rapid titration
• state of anesthesia reversible

Question 3

________: pressure molecules push against the walls of a container when in equilibrium at standard pressure

Answer 3

saturated vapor pressure

Question 4

___________ dictates the maximum number of molecules of vapor available for delivery to a patient

Answer 4

saturated vapor pressure

Question 5

Why require a vaporizer?

Answer 5

Dilutes the inhalent with a carrier gas to deliver a clinically safe concentration to the patient

Question 6

What effect does temperature have on Saturated Vapor Pressure?

Answer 6

↑ temp = ↑ SVP

Question 7

2 options if vaporizer gas mixing occurs

Answer 7

• send out for servicing to vaporizer manufacturer
• drain vaporizer and run a high fow of oxygen through for several hours then check for trace vapor levels using a gas analyzer

Question 8

PP of inhalent = ____ x _____

Answer 8

• concentration (%)

- atmospheric pressure (mmHg)

Question 9

to rapidly increase anesthetic depth, you should ______ and _________

Answer 9

• ↑ alveolar delivery

- minimize uptake from alveoli

Question 10

3 ways to ↑ alveolar delivery

Answer 10

• ↑ concentration
• ↑ fresh gas flow
• minimize breathing circuit volume

Question 11

___________: time it takes to make a 50 % change in a closed system

Answer 11

time constant

Question 12

the ____ the time constant, the faster the change in inhalant concentration and the faster anesthetic induction

Answer 12

lower

Question 13

______ time constants are needed to make a 98.5% change in the system

Answer 13

5

Question 14

agents with ____ solubility in blood → faster induction

Answer 14

low

Question 15

6 things to do for rapid induction or quick changes in anesthetic depth

Answer 15

• ↑ inspired concentration of inhalant
• ↑ fresh gas flow
• ventilate the patient
• minimize dead space within the circuit
• premedicate patients to minimize pain and anxiety
• utilize agents with low blood:gas partition coefficient

Question 16

6 things to do in order to facilitate rapid recovery from inhalant anesthesia

Answer 16

• minimize delivery of inhalant
• utilize agents with low blood solubility
• ↑ fresh gas flow
• assist ventilating the patient
• shorten duration of anesthesia
• ↑ CO

Question 17

_________ amount of inhalant that prevents gross purposeful movement in 50% of patients exposed to a noxious stimuli

Answer 17

Minimum Alveolar Concentration (MAC)

Question 18

potency is ________ related to MAC

Answer 18

inversely

Question 19

typically induce patients at ___-___ times MAC and maintain them at ___-____ times MAC

Answer 19

• 2-3 x

- 1.2-1.5 x

Question 20

Factors that ↑ MAC (4)

Answer 20

• hyperthermia
• hypernatremia
• drugs that cause CNS stimulation
• ↑ levels of excitatory NTs

Question 21

Factors that ↓ MAC (8)

Answer 21

• other anesthetics
• hyponatremia
• hypotension
• hypothermia
• PaO2 < 40 mmHg
• PaCO2 > 90 mmHg
• pregnancy
• ↑ age

Question 22

Factors that have no affect on MAC (5)

Answer 22

• gender
• normal resp gas concentrations
• duration of anesthesia
• metabolic acidosis/alkalosis
• mild to moderate anemia

Question 23

Effects of inhalants on the CV system

Answer 23

• ↓ myocardial contraction
• ↓ CO
• hypotension

Question 24

Effects of inhalants on the respiratory system

Answer 24

• respiratory depression

- bronchodilation

Question 25

2 advantages of Nitrous Oxide

Answer 25

• speeds induction and reduces inhalant dose

- minimal CV effects

Question 26

2 disadvantages of Nitrous Oxide

Answer 26

• avoid use in animals with closed gas spaces (GDV, colic pneumothorax)
• diffusion hypoxia at the end of anesthesia