Final Flashcards
Analgesia
Feel no pain
Amnesia
No memory
What comprises of balanced anesthesia?
Analgesia, amnesia, relaxation and hypnosis.
What are the desirable attributes of N2O?
Analgesic, anxiolytic, relative amnestic, rapid onset, titration, rapid cognitive recovery, minimal side effect.
Moderate Sedation
Independent airway.
Responds to physical or verbal command.
Deep Sedation
Partial loss of protective reflexes.
Inability to maintain airway.
Inability to respond to physical stimulation or verbal command.
General anesthesia
Unconciousness.
Partial or complete loss of protective reflexes.
Inability to maintain airway.
Inability to respond to physical stimulation or verbal command.
What are Guedel’s stages of Anesthesia?
Analgesia
Delirium/Excitement
Surgical anesthesia
Respiratory paralysis.
Pain
An unpleasant sensory and emotional experience arising from potential or actual tissue damage.
Provides damage protection to tissue.
Anxiety
A non-specific feeling of apprehension, worry, uneasiness, or dread the source of which may be vague or unknown.
Fear
A feeling of fright or dread related to an identifiable source recognized by the individual
Phobia
Any persistent or irrational fear of something specific such as an object, activity or situation that results in avoidance or desire to avoid the feared stimulus.
How do you assess fear and anxiety?
Physiologic indicators such as heart rate and BP. Behavioral indicators, Pt. history, anxiety questionnaires.
What controls the respiratory physiology?
Medullary center of the brainstem. Diaphragm and external intercostals assist inspiration.
Tidal volume
Volume of exhaled air after normal inspiration.
Minute Ventilation
Amount of gas brought into the lungs. In N2O sedation, concerns the amount of gas given. Tidal volume times respiratory rate.
What is the average minute ventilation?
6-7 L/min
Alveolar Ventilation
Concerns the amount of gas reaching the alveoli, and the amount capable for gas exchange. Usually about 150 mL less than the tidal volume.
What is the composition of Air?
79% Nitrogen and 21% Oxygen.
Is Nitrous Oxide dissolved in the blood?
NO! This allows for quick equilibrium in the blood and brain, and quick expulsion.
What is diffusion hypoxia?
Likely cause of post op headache, nausea, lethargy. Treated with post op 100% O2 for 3-5 min.
Nitrous oxide leaving blood causes lower O2.
Why shouldn’t hydrocarbons such as lubricants be used around the delivery system?
It is an oxidizing gas. Can ignite the hydrocarbons if there are rapid changes in pressure.
Molecular weight and specific gravity of N2O.
44
1.58 (Heavier than N2 and O2.
Blood Gas Partition Coefficient
Difference in partial pressures between gas and liquid. Determines how quickly it crosses the pulmonary membrane and enters the blood stream. If a drug is insoluble it will reach a equilibrium quickly and it will cross the BBB quickly/rapid onset.
What is N2O blood gas coefficient?
0.47
31 times that of N2.
Is N2O stored in the body?
Nope! Tissues don’t hold the N2O.
What is the concentration effect?
High concentration alveolar partial pressures are reached rapidly with little decrease in the concentration of the gas. Negative pressure pull more gas into the lungs. Less effect at analgesic doses.
What is the second gas effect?
With high concentrations causing rapid uptake, there is a simultaneous effect of increasing uptake of a second gas. This second gas uptake occurs faster than it normally would.
Minimum Alveolar Concentration
Amount of drug necessary to prevent movement in 50% of individuals with surgical stimulation.
What is the least potent of all anesthetic gases?
N20! MAC is 104%
What is the mechanism of action of N2O?
Opioid receptors.