Anesthetics-General

Question 1

describe the anesthetic ether

Answer 1

relatively safe for user
pungent odour
highly explosive

Question 2

describe the anesthetic chloroform

Answer 2

relatively dangerous *severe CVD, hepatoxic
non-pungent odour
non-explosive

Question 3

describe the anesthetic Nitrous oxide

Answer 3

only partial anesthesia, but excellent analgesia

used in dental clinics, and sometimes in hospitals

Question 4

describe the anesthetic cyclopropane

Answer 4

most populat 1929-1960

flammable - O.R. explosions

Question 5

describe the anesthetic halothane

Answer 5

improvement in safety
revolutionized anesthesia
introduced in 1956

Question 6

what are the 7 characteristics of the ideal inhalant anesthetic?

Answer 6

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

Question 7

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

Answer 7

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

Question 8

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

Answer 8

halothane, isoflurane and sevoflurane.

Question 9

what are the 4 requirements for optimal anesthesia?

Answer 9

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

Question 10

how is the anesthesia administered?

Answer 10

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

Question 11

what is the goal of a premedication?

Answer 11

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

Question 12

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

Answer 12

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.

Question 13

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

Answer 13

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

Question 14

what are premedications?

Answer 14

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

Question 15

what are the 3 main types of premedications?

Answer 15

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

Question 16

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

Answer 16

benzodiazepines (BZDs)

1. diazepam, and lorazepam

Question 17

why is diazepam a useful pre-med?

Answer 17

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

Question 18

what is a GABAa R?

Answer 18

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.

Question 19

what are the most common GABAa R subunits?

Answer 19

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

Question 20

what are endozepines?

Answer 20

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

Question 21

what are BZDs a good pre-medication?

Answer 21

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.

Question 22

what are the most common adverse effects of BZDs?

Answer 22

drowsiness and confusion

Question 23

what are some adverse effects/ overdose?

Answer 23

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

Question 24

what makes diazepam useful as a premed?

Answer 24

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