General Anesthetics

Front 1

Why use Nitrous Oxide

Back 1

used in conjunction w/ other drugs in anesthesia

Front 2

Mechanism of action of NO

Back 2

inhaled general anesthetic

Front 3

Pharmokinetics of NO

Back 3

not blood soluble fast induction

Front 4

CV effects of NO

Back 4

cause no CV depression

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Respiratory effects of NO

Back 5

respiratory depressant

Front 6

What kind of patients is NO good for?

Back 6

Good for asthmatics because will powerfully dilate constricted bronchioles

Front 7

Mechanism of action of Halothane

Back 7

inhaled general anesthetic

Front 8

Pharmokinetics of Halothane

Back 8

very blood soluble
slow induction

Front 9

Respiratory effects of Halothane

Back 9

respiratory depressant

Front 10

Is halothane okay for Asthmatics?

Back 10

yes because it will dilate constricted bronchioles

Front 11

How can you speed induction of Halothane?

Back 11

increase the patient's respiratory rate

Front 12

Why use Propofol

Back 12

for hypnosis/amnesia, increased ICP. (selection note: has less cardio effects than Thiopent)

Front 13

Drug action of Propofol?

Back 13

enhance GABA-ergic actions, works on B subunit of GABAA, , peak effect is in 60-90 seconds, duration is 8-10 minutes

Front 14

Mechanism of action of Propofol

Back 14

General IV anesthetic
#1 used today

Front 15

Pharmokinetcis of Propofol

Back 15

Very fat soluble stored in a fat emulsion

Front 16

CV effects of Propofol

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Little change in heart rate, DON’T GET REFLEX TACHY w/propofol; does cause some HYPOtension b/c baroreflex is blocked

Front 17

Respiratory effects of Propofol

Back 17

respiratory DEPRESSANT

Front 18

CBF, ICP, IOP, CMRO2 affects of propofol

Back 18

decreases all four

Front 19

What kinds of patients is propofol for?

Back 19

elimination is by multiple routes which is good (lung/liver/kidney); anti-emetic activity, well-being on emergence, pts ambulate sooner

Front 20

Notes about propofol

Back 20

NOT for pediatrics (metabolic acidosis risk); no asthmatics (respiratory depressant effect); NOT for volume-contracted pts. Pts can have pain on injection or myoclonus

Front 21

Why use thiopental

Back 21

increased ICP, or FOCAL ischemic injury

Front 22

What is the action of Thiopental

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enhances GABA-ergic actions; has rapid onset (15-30 seconds)

Front 23

Pharmokinetics of Thiopental

Back 23

very fat soluble and very basic meaning it can precipitate out other drugs

Front 24

CV effects of Thiopental

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venodilation causes reflex tachycardia which combined w/ myocardial depression effect-->"Pearl Harbor effect"=MI in some pts; does cause some HYPOtension

Front 25

CBF, ICP, IOP, CMRO2

Back 25

decreases all four

Front 26

Respiratory effect of Thiopental

Back 26

respiratory DEPRESSANT

Front 27

What sorts of patients is Thiopental for?

Back 27

note that elimination is not as good as Propofol which has multiple routes…levels fall due to redistribution to other tissues and then elim via liver.

Front 28

Caveats with Thiopental

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NOT for Global Ischemic Injury or Asthmatics; see some ALLERGIC or ANAPHYLACTIC Rxns; TISSUE irritatin or NECROSIS

Front 29

Why use Etomidate

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IS good for VERY SICK patients w/CV disease, inc. ICP, trauma, anursym, good if CARDIAC PSYCH patient

Front 30

Mechanism of action of Etomidate

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enhances GABA-ergic actions; produces hypnosis w/o analgesia

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Pharmokinetics of Etomidate

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ENDOCRINE effects here, so no Addison's Dx pts or steroid therapy pts!

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CV effects of Etomidate

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minimal heart effects AND minimal effects on Blood pressure (normotension!)

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Respiratory effects of Etomidate

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minimal respiratory effects

Front 34

Effect on IOP, ICP, CMRO2, and CBF of Etomidate

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all four decrease; note this drug does show stimulation on EEG, so is NOT for SEIZURE patients!

Front 35

Who can get Etomidate

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better than Propofol or Thiopental in volume-contracted pts b/c no hypotension effects!!; OKAY for asthmatics

Front 36

Caveats with Etomidate use

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patients get very nauseous, causes emesis or myoclonus; note endocrine suppression effects that could cause special concerns!

Front 37

Why use Ketamine

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profound analgesia; is a treatment for Opioid induced hyperalgesia (OIH) if tmnt w/opioids makes pain worse

Front 38

Mechanism of action of Ketamine

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has more of a CENTRAL mechanism of action, depresses cortical function, stimulates limbic system, including hippocampus
Given IV

Front 39

PK of Ketamine

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highly lipid soluble

Front 40

CV effects of Ketamine

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major cardiac stimulation (increased HR, BP & CO)

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CBF, ICP, IOP, CMRO2

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WATCH OUT HERE: all four INCREASE--> increased ICP, increased cerebral oxygen needs. See CNS excitation here as well so no psych, seizures.

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Respiratory Effects of Ketamine

Back 42

minimal respiratory effects

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Caveats with Ketamine

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*Prevent emergence delirium in patients w/midazolam (a benzo); is OKAY for asthmatics NOT for psych patients (emergence delirium); NOT for ischemic heart dx (cardiac stimulant); NOT for INCREASED ICP (increases it!); no open eye injuries or aneurysms!