General Anesthesia and Adjuncts Flashcards Preview

Pharmacology Test #6 > General Anesthesia and Adjuncts > Flashcards

Flashcards in General Anesthesia and Adjuncts Deck (72)
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1

Triad of Anesthesia

1. Analgesia
2. Amnesia
3. Skeletal muscle relaxation

2

Triad plus of anesthesia includes

loss of consciousness, loss of sensory function, autonomic inhibition

3

Types of Anesthesia

1. General
2. Spinal (subarachnoid in CSF)
3. Epidural
4. Regional (Nerve trunk block)
5. Local
6. Monitored anesthesia care/sedation

4

General anesthesia modes of deliver

1. Inhalational
2. Intravenous
3. Lipid soluble or able to cross BBB

5

Properties of inhalational anesthetics

rapid access to vascular system (brain); allows direct effects on pulmonary system

6

Properties of IV anesthetics

immediate access to vascular system; less than a minute (in the brain in 26 sec); advent of computer controlled pumps

7

Balanced anesthesia

combination of inhaled intravenous medications

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Major anesthesia

IV induction, inhalational maintenance, muscle relaxant

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Characteristics of anesthetic

1. reduces excitability of the membranes
2. no anesthetic specific receptors known
3. no anesthesia specific antagonists

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Stage 1 of anesthesia

analgesia - initially without amnesia

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Stage 2 of anesthesia

disinhibition - delirium and excitement; amnesia, irregular respiration, retching, incontinence

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Stage 3 of anesthesia

surgical anesthesia: unconscious, no pain perception, respiration regular again to apneic, BP maintained, 3 planes with eye changes

13

Stage 4 of anesthesia

Medullary depression: spontaneous respiration ceases, severe respiratory cardiovascular depression, death ensues without support

14

Characteristics of the ideal anesthetic

1. quick in - rapid induction of anesthesia
2. quick out - rapid recovery
3. non-irritating to airway
4. minimal physiologic trespass - nondisruptive and nontoxic
5. lack of interactions with other drugs
6. nonflammable, muscle relaxant properties

15

Dalton's law

anesthetic exerts partial pressure proportional to % anesthetic in mixture

16

Fick's law

anesthetic diffused down its concentration gradient

17

Henry's law

amount of anesthetic dissolved in a liquid is proportional to partial pressure of the anesthetic in the mixture

18

Minimum alveolar concentration (M.A.C.)

minimum alveolar concentration at 1 atm that prevents movement in 50% of patients in response to a painful stimulus such as a surgical incision or clamping of the tail with a hemostat/clamp

19

Defines potency of inhalational anesthetics and serves as a means to compare anesthetics

Minimum alveolar concentration (M.A.C.)

20

The lower the MAC,

the more potent the agent

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Factors decreasing MAC (less anesthetic agent is required)

increasing age, hypothermia, CNS depressants/drugs, acute EtOH intoxication, pregnancy, alpha adrenergic drugs (clonidine)

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Factors that increase the MAC requirements (more anesthetic agent is required)

hyperthermia, chronic ethanol abuse, increase CNS neurotransmitters (MAO inhibitors)

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Factors that have no change in MAC

duration of anesthetic, gender

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Blood-gas partition coefficient

relative solubility in blood vs air; determines uptake alveoli to blood, thus determines rate of induction

25

Solubility is approximately

blood-gas coefficient

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High blood solubility

slow induction

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Low blood solubility

rapid induction

28

Induction of high solubility anesthetic hastened by

hyperventilation

29

"Laughing gas"

nitrous oxide

30

Properties of nitrous oxide

insoluble, nonflammable, rapid onset, excellent analgesia and sedation, no skeletal muscle relaxation