Ga Flashcards
(43 cards)
What are the three principal components of anesthetic action?
Immobility, amnesia, unconsciousness
These components define the efficacy of anesthetics during surgical procedures.
What is the concept introduced by Edmond Eger to quantify the potency of inhalational anesthetics?
Minimal alveolar concentration (MAC)
MAC is used to measure the concentration of anesthetic required to prevent movement in 50% of subjects exposed to a painful stimulus.
What are the two types of memory differentiated by memory researchers in the context of anesthesia?
- Explicit memory
- Implicit memory
Explicit memory involves conscious awareness, while implicit memory pertains to unconscious information acquisition.
Which regions in the brain are identified as involved in generating personal awareness?
- Cerebral cortex
- Thalamus
- Reticular activating system
These regions interact to produce a state of consciousness, which is disrupted by anesthetics.
What are the core patient factors in selecting anesthesia?
- Organ function and co-morbidities
- CV
- Respiratory
- Liver
- Renal
- CNS
- Pregnancy
- Concurrent medications
- Pre-anesthetics
- Polypharmacy
These factors help tailor anesthesia to individual patient needs.
What neurotransmitter is primarily associated with the mechanism of action of general anesthetics?
Gamma-aminobutyric acid (GABA)
GABA is crucial for inhibiting neuronal activity in the CNS.
What is the difference between volatile and gaseous anesthetics?
- Volatile anesthetics: Low vapor pressures, high boiling points, liquids at room temperature
- Gaseous anesthetics: High vapor pressures, low boiling points, gas form at room temperature
This distinction affects their administration and physiological properties.
What factors control the uptake of anesthetics?
- Solubility
- Cardiac output
Solubility influences how anesthetics transfer from lungs to blood, while cardiac output affects pulmonary blood flow.
Why is the induction of anesthesia slower with more soluble anesthetic gases?
More soluble anesthetics take longer to achieve the same partial pressure in blood as in the alveoli
For example, halothane is more soluble than nitrous oxide, leading to slower induction.
What factors govern the rate of recovery from inhalation anesthesia?
- Blood:gas partition coefficient
- Pulmonary blood flow
- Magnitude of ventilation
- Tissue solubility
These factors influence how quickly an anesthetic is eliminated from the body.
What are the characteristics of inhaled anesthetics that are relatively insoluble in blood?
They are eliminated at faster rates than more soluble anesthetics
Examples include nitrous oxide, desflurane, and sevoflurane, which allow for quicker recovery.
Which inhaled anesthetics are associated with a slower recovery due to higher solubility?
- Halothane
- Isoflurane
These anesthetics have higher blood and brain solubility, leading to prolonged recovery times.
What is the role of ventilation in the elimination of anesthetics?
Ventilation helps control the speed of induction and recovery from inhaled anesthesia
Increasing the concentration of anesthetic in inspired gas and alveolar ventilation can enhance the process.
What are the acute toxicities associated with anesthetic agents?
- Nephrotoxicity
- Hematotoxicity
- Malignant hyperthermia
- Hepatotoxicity
These toxicities can arise from exposure to various anesthetic agents.
Which inhaled anesthetic is not metabolized by human tissues?
Nitrous oxide
It is primarily eliminated through exhalation rather than metabolism.
What cardiovascular effects do volatile anesthetics have?
They depress normal cardiac contractility and decrease mean arterial pressure
The extent of these effects correlates with the alveolar concentration of the anesthetic.
What renal effects do inhaled anesthetics usually cause?
Decrease in glomerular filtration rate (GFR) and urine flow
These effects are generally minor compared to surgical stress and are reversible after discontinuation.
What is the effect of halogenated anesthetics on uterine smooth muscle?
They are potent uterine muscle relaxants
This effect can be beneficial during certain surgical procedures but may increase uterine bleeding.
What is the classification of anesthetic agents?
- Inhaled anesthetics: Halothane, Isoflurane, Desflurane, Sevoflurane, Nitrous Oxide
- Intravenous anesthetics: Propofol, Barbiturates (Thiopental), Benzodiazepines (Diazepam), Ketamine, Etomidate
This classification helps in understanding the different types and their applications.
What are the main classes of inhaled anesthetic agents?
Inhaled anesthetic agents include:
* Halothane
* Isoflurane
* Desflurane
* Sevoflurane
* Nitrous Oxide
What are the main classes of intravenous anesthetic agents?
Intravenous anesthetic agents include:
* Propofol
* Barbiturates (Thiopental)
* Benzodiazepines (Diazepam)
* Ketamine
* Etomidate
Which intravenous anesthetic is most frequently administered for induction of anesthesia?
Propofol
What is the presumed mechanism of action of propofol?
Potentiation of the chloride current mediated through the GABA A receptor complex.
How is propofol metabolized in the body?
Rapidly metabolized in the liver; inactive water-soluble compounds are excreted through the kidneys.
