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Flashcards in Anesthetics-General Deck (24)
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describe the anesthetic ether

relatively safe for user
pungent odour
highly explosive


describe the anesthetic chloroform

relatively dangerous *severe CVD, hepatoxic
non-pungent odour


describe the anesthetic Nitrous oxide

only partial anesthesia, but excellent analgesia
used in dental clinics, and sometimes in hospitals


describe the anesthetic cyclopropane

most populat 1929-1960
flammable - O.R. explosions


describe the anesthetic halothane

improvement in safety
revolutionized anesthesia
introduced in 1956


what are the 7 characteristics of the ideal inhalant anesthetic?

chemically stable with out preservatives
compatible with machines
produces unconsciousness while maintaining brainstem function
non-pungent odour
negligible toxicity


what is typically used today (chemical backbone of the anesthetic)?

halogenated hydrocarbons, since halogenated aliphatic hydrocarbons or ethers.
the replace them of H- with halogens reduces flammability and enhances stability; more f- more stable.


what are the 3 most comment selected inhalants that are used today?

halothane, isoflurane and sevoflurane.


what are the 4 requirements for optimal anesthesia?

1. unconsciousness
2. analgesia
3. amnesia
4. muscle relaxation


how is the anesthesia administered?

low [ ] inhalant to render patient unconscious, and use low [] of other drugs to inhibit pain or relax the muscles.
1. administer sedative or anioxlytic and analgeesic
2. induce unconsciousness
3. maintain in unconscious state


what is the goal of a premedication?

1. sedation
2. analgesia (intra/post operative pain relief)
3. reduce [] of induction agent and anesthetic required.


what are induction agents? (what do they do/ goal)

product general anesthesia
administered IV
goal: rapidly render patient unconscious
effects wear off rapidly
helps speed up stage 2 to 3 in the stages of anesthesia during induction.


what are the 4 stages or planes of anesthesia during induction?

1. state of analgesia (semi-consciousness)
2. stage of excitement, (struggle, comabitve behaviour)
3. stage or plane of surgical anesthesia (unconsious, ceased movement)
4. **To far process** stage of medullary depression--> death


what are premedications?

variety of injectable drugs used to calm patient, reduce amount of general anesthetics needed to inhibit pain intra- and post op


what are the 3 main types of premedications?

1. sedatives/ anxiolytics (calm patients)
2. hypnotics- to induce sleepiness
3. analgesics (minimiza/abolish intra & post op pain)


what is the major class of sedatives used and name two examples.

benzodiazepines (BZDs)
1. diazepam, and lorazepam


why is diazepam a useful pre-med?

aniolytic/sedative effect
muscle relaxant
*trade name is valium
it facilitates the binding of GABA to its receptor


what is a GABAa R?

its a hetero-pentameric lignand-gated chloride channel; when binded to GABA, the alpha unit opens the channel and hyper-polarized the cell, which inhibits the excitation/ AP. the overall effect depends on location of receptors and the regions of the brain that are inhibited.


what are the most common GABAa R subunits?

there are 21, the most common are 2alpha 1, 2beta2, and 1gama 2.


what are endozepines?

they are endogenous, meaning they bind to the same site s benzodiazapines.


what are BZDs a good pre-medication?

relatively safe -> need GABA to be present
BZD have little effect on CV system
Dose-dependent respiratory depression, but little effect at therapeutic dosages
hepatic metabolism.


what are the most common adverse effects of BZDs?

drowsiness and confusion


what are some adverse effects/ overdose?

do not combine with alcohol, can be fatal via CNS depression. overdose however can be reversed by the GABA R antagonist Flumazenil


what makes diazepam useful as a premed?

administered prior to anesthesia -> less anesthetic required to produce "surgical plane".
Also relaxes skeletal muscles.