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Flashcards in IV sedatives-hypnotics Deck (38)
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1

Advantage of propofol

More rapid return of consciousness with minimal residual effects compared to other induction agents

2

Propofol MOA

Increases GABA affinity for GABAa receptor - prolonged channel opening, increased Cl- influx

3

Effect of increased Cl- influx

Neuronal cell hyperpolarization - inhibition of the cell

4

Propofol metabolism

P450 - water soluble metabolites excreted via kidneys. <0.3% excreted unchanged in urine

5

Propofol induction dose:
MAC dose:
TIVA dose:

I: 1.5-2.5 mg/kg
MAC: 25-100 mcg/kg/min
TIVA: 100-300 mcg/kg/min

6

Propofol PONV dose:

Subhypnotic: 10-15 mg IV

7

Propofol CNS effects:

Decreased - CMRO2, CBF, ICP
DOES NOT EFFECT - cerebral autoregulation

8

Propofol cardiovascular effects:

Decreased - SVR, inotropy
DOES NOT EFFECT - HR
Decreased SVR may be augmented in hypovolemic, elderly, compromised LV function

9

Propofol SNS effect:

Suppression of sympathetic nervous system activity

10

Propofol effects respiratory:

Dose-dependent decrease ventilation

11

Propofol effects intraocular pressure:

Decreased immediately after induction of anesthesia

12

Etomidate MOA:

Increases GABA affinity for GABAa receptor - prolonged channel opening, increased Cl- influx

13

Etomidate metabolism:

Hepatic microsomal enzymes and plasma esterases

14

Etomidate induction dose:

0.2-0.4 mg/kg IV

15

Etomidate cardiovascular effects:

Minimal changes in - HR, SV, CO
Decreases - up to 15% decrease in MAP d/t decrease in SVR

16

5 Benzodiazepine effects:

Anxiolysis, sedation/hypnosis, anticonvulsant, anterograde amnesia, SK muscle relaxation

17

Benzodiazepine MOA:

Increased GABA affinity for GABAa receptor - increased frequency of channel opening, increased Cl- influx

18

Benzodiazepine amnesic effect?

Amnestic effect is greater than sedative effect - patients may be awake, but remain amnestic for events and conversations

19

Midazolam Vd elderly and obese:

Increased Vd resulting from enhanced distribution into peripheral adipose tissue

20

Midazolam metabolism:

Rapidly metabolized by hepatic and small intestine P450 (CYP3A4) - hydroxymidazolam (1/2 potency) is rapidly conjugated and renally excreted

21

Drugs that decrease midazolam metabolism?

cimetidine, erythromycin, calcium channel blockers, antifungal drugs - inhibit P450

22

Midazolam CNS effects:

Decreases CMRO2, CBF. Autoregulation is preserved.

23

Solo midazolam induction:

Increased ICP associated with laryngoscopy is not blunted

24

Midazolam respiratory effects:

Dose-dependent decrease in ventilation by decreasing hypoxic drive

25

Midazolam cardiovascular effects:

Decrease in BP, SVR. Increase in HR.

26

Midazolam doses:

Induction: 0.1-0.2 mg/kg
IV sedation: 1-2.5 mg
Onset 30-60 sec, Peak 5.5 minutes, Duration 15-80 min

27

Flumazenil MOA:

Benzodiazepine antagonist at GABA receptor sites, however lacks agonist activity

28

Flumazenil dose:

0.2 mg, subsequent doses of 0.1 mg q1min

29

Ketamine MOA:

Produces dissociative anesthesia by interrupting signals between the thalamus and cerebral cortex. Patient is amnesic and analgesic

30

Limit as sole anesthetic:

High frequency of emergence delirium