Flashcards in Inhalants Deck (24):
Effects of inhalant anesthetics?
Inhalants are administered and eliminated by the ____, have a _____&________ Titration making it easy to control over anesthetic depth, and are easy to ______.
predictable and rapid titration
Which inhalant is most/least expensive?
Desflurance $$$ > Sevoflurance $$ > Isoflurane
Saturated vapor pressure determines the
number of molecules of vapor available for delivery to a patient
Why do we need a vaporizer?
Dilutes the inhalant with a carrier gas (oxygen) to deliver a safe concentration to the patient
Modern vaporizers are all?
Temperature compensated (so that saturated vapor pressure is predictable and not changed by differing room temperatures)
The greater the vapor pressure of the inhalant the ______ the volatility
What do you do if someone puts the wrong inhalant in the vaporizer?
1. send to manufacturer for servicing
2. drain, run high flow oxygen for several hours then check for trace levels with an analyzer.
partial pressure =?
What does this mean at higher altitudes?
concentration x atm P
Harder to keep patients anesthetized at higher altitudes using the same concentration.
Rapid increase in Alveolar pressure will?
rapidly increase anesthetic depth
Two ways we increase anesthetic depth?
increase alveolar delivery & minimize uptake from alveoli
How do we increase alveolar delivery
Turn up concentration, increase fresh gas flow, minimize circuit volume
time to make a 50% change in a closed system; = Volume / Flow
How do we minimize uptake from alveoli?
1. use an agent with low blood solubility like Isoflurane
2. Slow CO
3. high alveolar: pulmonary blood partial pressure gradient
Summary for quickly changing anesthetic depth
1. inc. inspired concentration
2. inc. fresh gas flow
4. minimize dead space
5. pre-medicate for pain/anxiety
6. use agent with low blood:gas partition coefficient
Summary for quickly recovering from an inhalant?
1. Turn off vaporizer/remove excess from reservoir bag/remove patient from machine
2. use agent with low blood solubility
3. inc. fresh gas flow
4. assist with ventilation
5. shorten duration under anesthesia
6. increase CO
Potency of an inhalant is _______ to its MAC
potency of inhalants?
iso > sevo > desflurane
induce patients at _____ MAC
and maintain at _____ MAC
2-3 x (or ED95)
What will increase MAC?
hyperthermia, hypernatremia, drugs that stimulate the CNS, increased excitatory NTs
Effect of inhalants on the cardiovascular system?
decreased contraction, CO, hypotension. dose dependent
can tx with fluids, inotrope/vasopressors
Effect of inhalants on the respiratory system?
hypoventilation -> apnea
tx: support ventilation
Effect of inhalants on the Neurologic system?
increase ICP when >1 MAC, cerebral vasodilation, worsened by hypoventilation