Pharmacology - General Anesthesia (Exam 3) Flashcards
Medically induced loss of consciousness w/ concurrent loss of protective reflexes due to anesthetic agents
Anesthesia
Three goals of balanced anesthesia
1) calm
2) decrease pain
3) reduce adverse effects of anesthetics
Combined anesthetics from different drug classes to take advantage of the best properties to minimize side effects
Balanced anesthesia
Two main categories of anesthetics
Inhalation
IV
Name some scenarios where you would want to use general anesthesia in dentistry
- Highly invasive and long dental procedures
- Complicated Wisdom tooth removal
- Dental implants
- Facial and jaw reconstruction
- Treatment of traumatic facial injuries
MOA of general anesthetics
Block Excitatory Receptors (ketamine, nitrous oxide)
Amino butyric acid GABA receptor (benzodiazepines, etomidate)
Block G protein-coupled Receptors (halothane)
Perturb ion channels (e.g,. Calcium, potassium, sodium)
Name the 4 stages of anesthesia
1: analgesia
2: delirium and excitement
3: surgical anesthesia
4: medullary paralysis (overdose & death)
T/F: you can start surgery during Stage II
FALSE
This stage of anesthesia starts from loss of consciousness to beginning of irregular respiration
Stage II
Which stage is divided into 4 planes?
Stage III
Which stage is this?
Starts from onset of irregular resp to cessation of spontaneous breathing
Stage III
Return of regular respiration, muscle relaxation, and normal heart/pulse rates. Eyelid and swallowing reflexes are lost
Plane I from Stage III - surgical anesthesia
Begins with disappearance of respiratory function
Stage IV - medullary paralysis
Concentration of inhaled anesthetic needed to prevent movement in 50% of patients in response to a surgical stimuli
MAC - minimum alveolar concentration
Potency of inhaled anesthetic is inversely related to?
MAC and lipid solubility
The more lipid soluble an inhalant is….
The higher its potency (lipid/gas partition coefficient)
The concentration ratio of the inhaled anesthetic in the blood phase to the gas phase when equilibrium is achieved
Blood/gas partition coefficient
The higher the blood:gas partition coefficient…
The greater the blood solubility
What does an anesthetic with low blood solubility indicate?
Equilibrium is achieved rapidly
Quickly saturates the blood
Results in a rapid induction and recovery
Name that anesthetic!
Physical Characteristics: Colorless, Odorless
Very insoluble in blood and other tissues
Rapid induction of anesthesia 2-3 minutes
Quick recovery
Blood/Gas coef = 0.47
Completely eliminated by the lungs
Weak anesthetic and powerful analgesic
Low potency with MAC = 104%
Lipid solubility = 2.3
Nitrous oxide
Why do you usually have to administer nitrous with another anesthetic?
It’s a weak anesthetic but powerful analgesic
Pharmacological effects of nitrous
Induces conscious sedation, anxiety relief, analgesia, amnesia
May increase heart rate and respiration
Mild myocardial depression and hypoventilation