Anesthetic Mechanisms Flashcards
(39 cards)
What are the drugs used in monitored anesthesia
Midazolam for premedication, then propofol for the deeper sedation
What is the mechanism of action of propofol
GABAa agonist receptors
What are the general toxicities seen with inhaled anesthetics
- Nausea and vomiting
- Malignant hyperthermia if used with succinyl CoA
What is deep sedation
Decreased consciousness, loss of protective reflexes, no patent airway, lock of verbal responsiveness
What are the toxicity seen in the CV with local anesthetics
Block cardiac sodium channels and decrease the amount of excitability, conduction, contractility, arteriole dilation, and hypotension
What is conscious sedation
Used by dentists where the patient is awake and responsive
What is the method of epidural anesthesia
Injection into the epideral space to create a large area
What is the method of block anesthesia
Injection into the major nerve trunks, so results in a region distal to the site of injection (such as brachial plexus)
What are the toxicities of local anesthesia at low concentrations
- Sleepiness
- light headed
- visual and auditory disruptions
- restlessness
What are the characteristics of an anesthetic agent that high low blood solubility
Reaches high arterial pressure slowly, so it reaches equilibrium slowly, resulting in a slow onset of action
What is the mechanism that most general anesthetics work
- Activation of chloride channels for hyperpolarization (GABA and Glycine)
- Decreased excitatory channels activity
What is monitored anesthesia
Sedation based anesthetic technique for diagnostic and mino therapeutic surgical procedures, where premedication is given, then followed by another for deep sedation
What can be given to help control seizures and what is the mechanism
Benzodiazepine, which raising the threshold of seizure activity
What is the mechanism of action for local anesthetics
Blocks the voltage gated sodium channels, so there is no spread of the depolarization
What is the method of infiltration anesthesia
Direct injection into the tissues near peripheral nerve endings
What are the toxicities seen in high doses of local anesthetic
- Nystagmus
- Convulsions
- muscle twitching and fasciculation
What is the method of spinal anesthesia
Injection into the CSF in the lumbar space in order to produce a great area
Where are ester type agents metabolized
In the plasma by circulating enzymes
Which type of fibers are most susceptible to blockage by a local anesthetic
Type C (dorsal root and SNS) > Type B (pregang) > Type A delta
What are the characteristics of a gaseous anesthetic
High vapor pressure and low boiling point, so they are gas at room temperature
Where are amide-type anesthetics metabolized
In the liver by CYP450 and excreted in the urine
What is the mechanism of action of opioid analgesics in anesthesia
Given in combination with benzo
Where do inhaled anesthetics tend to accumulate and have an effect first
The organs receiving a higher cardiac output, such as the heart, liver, and kidneys, with the muscle tissues taking much longer
What are the characteristics of effects for an anesthetia
- Unconscious
- amnesia
- analgesia
- attenuated Autonomic responses
- immobility
