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Flashcards in non-barb IV induction agents Deck (78)
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1

What is the generic propofol prepared in?

what does this imply

sodium metabisulfite

Caution/avoid in asthmatics because this preparation leads to bronchospasm

2

propofol CV effects

  • HUGE ↓ in BP (25-40%)
    • Greater than with sodium pentothal (STP)
  • Dose dependent myocardial depression & vasodilation result in:
    • ↓ in SV, ↓ CO & ↓ SVR
  • Heart rate unchanged (? baroreceptor inhibition)
    • Baroreceptors do not activate nor are inhibited

3

non-barb induction drug that inhibits CYP450

Precedex

4

Ketamine amnesia

Produces ‘dissociative anesthesia’

  1.  depression of neuronal function in association areas of the cerebral cortex & thalamus
  2. stimulation of the hippocampus (limbic systems)

produces a marked sensory loss and analgesia, and amnesia 

5

Etomidate is what drug class?

Carboxylated Imidazole derivative

Imidazole= C3H4N2

6

Etomidate

CNS effects

  • Rapid loss of consciousness after a single dose
  • Cerebral vasoconstriction leads to decreased CBF, ICP, CMRO2, IOP
  • Increases EEG activity in epileptogenic foci
  • increases myoclonic movements more than propofol and methohexital (disinhibiting extrapyramidal system)
  • Anticonvulsant properties, BUT can be associated with Grand Mal Seizures (caution in pt with hx of seizures)
  • High N/V

7

induction agent that supresses cortisol synthesis

etomidate (Amidate)

8

Precedex metabolism?

rapid metabolism

conjugation and CYP45 metabolism

Metabolites cleared in urine and bile

Inhibits CYP-450 (can interfere with opioid clearance)

9

Etomidate causes  _1_  

via inhibition of the coversion of _2_ to _3_

The enzymes inhibited are _4_ and _5_

This inhibition may provide an advantage of having _6_

  1. dose-dependent adrenocortical supression (adrenal cortex)
  2. cholesterol to
  3. cortisol
  4. 11 beta-hydroxylase
  5. 17-alpha-hydroxylase
  6. Stress free anesthesia

10

Ketamine pharmacokinetics

Vd, lipid solubility, onset, DOA, E½t

Large Vd (3 L/kg)

High lipid solubility

onset - 30 sec(rapid), short duration

max effect for 1 min, effect terminated by redistribution

DOA 5-10 min

E1/2t 2-3h

11

Which of these non-barb induction agents have analgesia effects?

(Ketamine, etomidate, propofol)

KETAMINE

12

Propofol metabolism

depends on hepatic blood flow ; clearance exceeds hepatic blood flow

CYP450; mainly by glucuronidation

metabolized to 2 inactive metabolites: glucuronide & sulfate & 1 weak metabolite 1-hydroxypropofol (1/3 potency)

excreted by urine

13

myoclonus side effect comparison 

thiopental, etomidate, methohexital, propofol

etomidate > methohexital (brevital) > propofol > thiopental (STP)

14

drugs that induce changes in the EEG

Thiopental (Pentothal)

Propofol

 

15

Amnestic dose of propofol 

30 mcg/kg/min

16

Ketamine class

Phencyclidine derivative (PCP)

Non-barb induction agent

17

What solvent is etomidate prepared in?

Propylene glycol solvent (anti-freeze)

these were the older drugs, newer drugs don't cause pain anymore (?)

18

With Etomidate physiologic activity will be ___________ in an acidotic patient

Less, but not much.

It is a basic solution with a pH of 8.2, however the pKa is 4.2 and it is 99% ionized at physiologic pH

19

What is the structure of propofol?

2,6-di-iso-propylphenol

Oil at room temp, insoluble in aqueous solution

very lipid soluble

20

What type of patients may have and exaggerated respone to hypotension with propofol?

  1. Hypovolemic
  2. Elderly
  3. those with poor LV function d/t CAD

Rapid hydration (bolus) prior to administration is recommended

21

How does ampofol formulation differ from diprovan/propofol preparation?

Low lipid formula: 5% soy, 0.6% egg lecithin

No preservative needed

More pain with injection

22

propofol other side effects

  • Pain on injection (premedicate with lidocaine)
  • Crosses placenta, rapidly removed from fetal circulation
    • Usually use just to induce

23

Which non-barb induction agent potentiates neuromuscular blockade?

Etomidate

Enhances NDMR activity

24

Ketamine is a racemic mixture of which enantiomers?

Equal parts R and S enantiomers

S enantiomer is

  • more potent analgesic
  • faster metabolism
  • lower incidence of emergence delirium

25

Does propofol depress the spinal cord?

NO

26

Potential side effects of propofol due to lipid emulsion

  1. risk of infection
  2. pain on injection
  3. hypertriglyceridemia
  4. potental for pulmonary embolism
  5. bradycardia (rare 1.4/100,000)

27

Etomidate doses:

induction, maintenance, sedation

Induction 0.2 - 0.3 mg/kg

Maintenance: 10 mcg/kg/min with N2O and opioid (but inc PONV)

Sedation: 5-8 mcg/kg/min 

28

propofol

onset, DOA, E½t, redistribution time, contex sensitive time ½t

onset ≈30 sec

DOA 5-10 min (then redistributed)

E½t 0.5-1.5 hrs

redistribution time 2-8 min

contex sensitive time ½t 40 min

29

Propofol induction dose?

Adult vs. toddler

GA maintenance dose?

Sedation infusion dose?

  • Induction 1 - 2.5 mg/kg, up to 3mg/kg
    • toddlers/Kids higher dose bc they have a larger central distribution and higher clearance rate
    • Elderly need lower dose due to smaller central distribution and lower clearance rate
  • GA 100-300 mcg/kg/min
  • Sedation 25-100 mcg/kg/min

30

Dexmedetomidine MOA

Central and peripheral alpha2 adrenergic receptor agonist 

  • producing sedation by
    • decreasing sympathetic nervous system activity
    • decreasing the level of arousal
  • regulates the cardiovascular system by
    • inhibiting norepinephrine release 
  • decreases sympathetic outflow from the CNS and augments cardiac vagal activity