General Anesthesia Flashcards
Name the 4 Inhaled Anesthetic Agents.
1) NITROUS OXIDE
2) DESFLURANE
3) SEVOFLURANE
4) ISOFLURANE
Name the 4 Intravenous Anesthetic Agents.
1) PROPOFOL
2) ETOMIDATE
3) KETAMINE
4) DEXMEDETOMIDINE
What are the 5 Major effects of a general anesthetic?
1) Unconsciousness
2) Amnesia
3) Analgesia
4) Attenuation of Autonomic Reflexes
5) Skeletal Muscle Relaxation
What are the 3 conditions of the IDEAL general anesthetic?
1) RAPID smooth loss of consciousness
2) RAPID reversal on discontinuation
3) WIDE margin of safety
What is CONSCIOUS SEDATION?
CONSCIOUS SEDATION (3 glasses of wine analogy)
1) AMOUNT - MINIMAL amount of amnestic and opioid
2) PATIENT INTERACTION - Still able to converse, respond to stimlui and commands
3) ABC - Able to protect airway and maintain ventilation
What is the continuum of conscious sedation -> General anesthesia?
Decrease in any of the 3 conditions of conscious sedation (Low amount, pt still able to interact and respond to stimuli, maintain airway and ventilation)
What condition distinctly differentiates SEDATION from GENERAL ANESTHESIA?
When the pt has LOST the ability to protect the airway and maintain normal ventilation
General anesthesia is actually PREFERRED by operators bec immobility/unresponsiveness to protecting the airway (e.g. aspirating, vomiting) is desired [Prevents potential pneumonitis]
What is BALANCED ANESTHESIA?
Utilizing SMALL doses of multiple agents (Inhaled, IV, Opioids, Benzodiazepines, Neuromuscular blocking drugs) to MINIMIZE side effects and MAXIMIZE efficacy
GASEOUS vs VOLATILE: What is the one commonly used gaseous anesthetic?
NITROUS OXIDE - Gaseous inhaled anesthetic (Gas at room temperature) Has GOOD Amnestic, and analgesic actions
GASEOUS vs VOLATILE: Is N2O inhaled agent used alone?
NO, almost ALWAYS used in addition to other agents
GASEOUS vs VOLATILE: What are the 3 volatile inhaled agents used?
VOLATILE - Liquid at room temperature
1) Desflurane
2) Isoflurane
3) Sevoflurane
GASEOUS vs VOLATILE: What is the chemical structure of volatile inhaled agents? What is its importance?
D,I,S are FLUORINATED ethers - Fluoride addition stabilizes the ether -> Prevents ether flammability
INHALED ANESTHETIC ONSET: What is the major factor determining the ONSET of an INHALED anesthetic?
1) HIGH Fa - Alveolar fraction of anesthetic to its target organ (CNS) or Alveolar partial pressure
INHALED ANESTHETIC ONSET: How does the anesthesiologist control for a HIGH Fa (alveolar fraction) to CNS? (2)
1) HIGH Fi - Inspired fraction or partial pressure (vaporizer reading)
2) HIGH ALVEOLAR VENTILATION - High respiration rate of the pt
INHALED ANESTHETIC ONSET: What is the other factor that the anesthesiologist can NOT control for but still contributes to a HIGH Fa?
LOW SOLUBILITY (INSOLUBLE) of Inhaled Agent (Blood: Gas partition coefficient) *Solubility is INVERSELY proportional to onset*
INHALED ANESTHETIC ONSET: Rank the onset of the inhaled anesthetics based on solubility.
N2O (Least soluble) > DESFLURANE > SEVOFLURANE > ISOFLURANE (Most soluble)
“No doctor sounds ill”
INHALED ANESTHETIC EMERGENCE: What is the Fi during emergence
ZERO - No more of the anesthetic is being delivered to the pt
INHALED ANESTHETIC EMERGENCE: What is the major determining factor of an inhaled anesthetic’s emergence? What is a minor factor?
1) MAJOR: Alveolar Ventilation - The quicker the pt breathes, the more the gas can be removed from the lungs
2) MINOR: Metabolism
What is MAC? What does it measure?
Minimal Alveolar Concentration - Measures potency
Ex: 1MAC»_space; 10MAC in potency
How is MAC experimentally determined?
Basically P50 - ALVEOLAR partial pressure of the inhaled anesthetic at which 50% of the population of non-muscle relaxed pts remain immobile at skin incision