Pharm Quiz #9 Flashcards by Joshua Voss

What is the hallmark characteristic of Propofol as an induction agent?

Most rapid and complete awakening of any induction drug
It has a rapid return of consciousness
Minimal residual CNS effects

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What is the #1 adverse affect of Propofol?

Pain on injection when a small vein is used

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How can you minimize the #1 adverse affect of Propofol?

Minimize pain of injection by using larger veins, lidocaine or an opioid

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What is responsible for the prompt awakening after receiving Etomidate?

prompt awakening due to REDISTRIBUTION from brain to inactive tissues although rapid metabolism plays a secondary role

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Does Etomidate have any post op affects?

It has a GREATER INCIDENCE OF PONV

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Does Etomidate have any negative affects on specific patient populations?

Greater frequency of excitatory spikes on EEGs, may activate seizure foci, so USE WITH CAUTION IN EPILEPSY PATIENTS—>avoid in patients with history of seizures!!

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How does Etomidate affect the adrenal-cortical?

Etomidate causes adrenocortical suppression via dose dependent inhibition of the conversion of cholesterol to cortisol
Specific enzyme inhibited is 11-bets-hydroxylase

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What illegal drug is Ketamine chemically related to?

PCP derivative that produces dissociative anesthesia—>”the lights are on but nobody is home”

It is a “dirty drug”

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What is the #1 mechanism for the CV effects of Ketamine?

Greater SNS outflow—>patients with depleted catecholamine reserves may drop BP with ketamine as direct myocardial depressant effects are blocked by increased SNS outflow.

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By what mechanism does Ketamine cause emergence delirium?

Due to depression of inferior colliculus and medial geniculate nucleus

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What is the chemical class of propofol?

Alkyl phenols

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What is the chemical name for propofol?

2,6-diisopropylphenol

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Which drug has the most rapid and complete awakening of any induction drug?

propofol

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Propofol has pain on injection when____veins are used. Minimize pain by _____, _____ and _____.

Small
large veins
Lidocaine
Opioids

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Propofol interacts with _____, the principal inhibitory neurotransmitter.

GABA

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Propofol leads to a slower rate of dissociation for GABA from receptors allowing increased durations of opening of ____ channels and hyper polarization of cell membranes.

Chloride

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How is propofol cleared/metabolized in the body?

Hepatic and extra-hepatic metabolism
Tissue uptake by the vessel rich group
Very rapid clearance

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Less than ____ of propofol is excreted unchanged in urine?

0.3%

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All metabolites of propofol are pharmacologically ___?

Inactive(water soluble sulfate & glucuronic acid compounds excreted in urine)

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What is the elimination 1/2 time of propofol?

0.5 to 1.5 hours

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Does the length of infusion alter the context sensitive 1/2 time?

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T or F: Propofol has a long effect-site equilibration time like Thiopental.

False—>it is short

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Does cirrhosis and ESRD impair propofol elimination?

No it does not

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There is an impairment of elimination with patients over ___ years old.

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Propofol crosses the ___ but rapidly cleared from fetal circulation.

placenta

Give propofol ___ to avoid cardiovascular adverse effects

incrementally

True or False: Propofol is a trigger agent for malignant hyperthermia?

falso; it is not

For total intravenous anesthesia, we can dose the patient based off of ___ for sedation:

IBW

Consciousness in sedation doses range from ___ to ___ mcg/kg/min.

25 - 300(minimal analgesia effects, excellent amnesia effects)

What is the propofol intravenous dose for post-op heart patients to blunt tachycardia and hypertension?

25 - 75 mcg/kg/min

For induction of anesthesia, 1 to 2.5 mg/kg produces blood levels of ___ mcg/ml.

2 - 6

Children need greater doses of propofol (___) due to larger ___ and greater ___.

2.5 - 3.5 Larger central distribution volumes greater clearance rates

Elderly patients need ___ to ___ % smaller doses of propofol due to smaller ___ and smaller ___.

25 - 50% Central distribution volumes Clearance rates

List three advantages of using propofol for intravenous sedation.

Prompt recovery no residual sedation low incidence of nausea and vomiting

T or F, propofol will reduce nausea and vomiting in doses that do not produce anesthesia?

True

Is propofol a good choice of drug for patients receiving electro convulsive therapy?

No, propofol has anti-convulsant properties dut to GABA mediated pre and post synaptic inhibition(decreased seizure activity 35-45%)

A patient has Pruitis from post epidural/intrathecal opioid administration. Should they receive propofol?

Yes, propofol treats prates of neuroaxial opioids due to decreased spinal cord activity(intrathecal opioids give prates by segmental excitation within the spinal cord).

T or F, propofol decreases cerebral metabolic oxygen requirements, cerebral blood flow and ICP.

True

How does propofol effect EEGs?

Similar to thiopental including burst suppression in high doses. Doesn't change evoked potential monitoring.

What does propofol do to sympathetic vasoconstrictor nerve activity?

Inhibits it(decreases in BP)

How does propofol effect inotropic activity?

Negative inotropic effects by decreasing intracellular Ca levels

Propofol increases the ___ in pediatrics strabismus surgery.

Oculocardiac reflex(5 and dime baby!!!)

___ stimulation reverses blood pressure drops of propofol, although to a lesser degree than blood pressure drops seen with thiopental.

Laryngoscopy

Propofol 2 mg/kg does NOT blunt ___ responses to rapid increases in desflurane.

Cardiovascular

List four factors that effect hypotension with propofol.

hypovolemia elderly depressed LV function dehydration(hypovolelmia!!!)

Propofol does not change the heart conduction system thus the ___ is often unchanged.

heart rate

For respiratory effects, propofol decreases both ___ and ___.

Tidal volume and respiratory rate

Ventilatory responses to ___ and ___ are blunted.

Co2 and arterial hypoxemia

How does propofol effect the patient airway?

bronchodilation reduces intraoperative wheezes in asthma patients Hypoxic pulmonary vasoconstriction remains intact(HPV-hyperventilatory response that protects our breathing response)

What causes green urine with propofol?

Due to excreted phenols and cloudy urine from uric acid excretion.

Propofol has addiction potential, may cause(3 items).

intense dreams amorous behavior hallucinations

Propofol supports ___ and ___ growth.

E. coli | Pseudomonas

What is the most common adverse effect to Propofol?

Pain on injection

How do you avoid propofol pain on injection?

Use large vein, use opioids and lidocaine

T or F, Propofol may abolish Parkinson tremors so use cautiously in stereotactic near tremor ablation surgeries.

True

What chemical characteristic makes Etomidate different than any other intravenous induction agent?

a carboxylated imadazole ring(makes etomidate water soluble at acidic pH and lipid soluble at physiologic pH

What is the mechanism of action for etomidate?

Enhances the effects of CNS inhibitory neurotransmitter GABA

Aqueous solutions of Etomidate are unstable at physiologic pH-so formulated in 0.2% solution with 35% ___.

propylene glycol

Etomidate has a high incidence of ___.

Pain with intravenous injection(more painful than Propofol)

What is the pKa of Etomidate?

4.2

Etomidate's volume of distribution is ___ due to ___ tissue uptake.

large, large | due to moderate lipid solubility

Regardless of plasma etomidate levels, etomidate is normally ___ plasma protein bound.

76%

T or F, etomidate has rapid brain penetration.

True

Prompt awakening from Etomidate is due to what?

redistribution(rapid metabolism plays a secondary role)

On a chemical structure level, how is etomidate metabolized?

Hydrolysis of ethyl ester side chain to carboxylic acid ester, a water soluble and inactive compound

How does the body metabolize and excrete etomidate?

97% metabolism by hepatic microsomal enzymes and plasma esterase's 85% urine excretion and 15% bile excretion (5 times greater clearance than thiopental, elimination 1/2 time 2-5 hours)

Etomidate uses-What is onset? What is frequently seen?

Onset- 1 arm to brain circulation time Frequent involuntary myoclonic movements(Kramer-can use in unstable CV patients)

Etomidate has ___ psychomotor recovery than Thiopental but ___ than Methohexital.

Quicker | slower

Does Etomidate have analgesic properties?

Would you rather use Etomidate for ECT or Thiopental/Propofol?

Etomidate

What is the principle reason and indication for the use of Etomidate?

Unstable CV patients

One of the downsides of etomidate is what?

Transient suppression of adrenocortical function

What is post operative complication of Etomidate?

greater incidence of PONV

Because Etomidate has a greater frequency of excitatory spikes on EEGs and may activate seize foci, it is contraindicated to give it to a patient with what type of neuro history?

Caution in epilepsy patients

Even though you should not give etomidate in epilepsy patients, etomidate can terminate ___?

Status epilepticus

Etomidate is an induction drug of choice for patients with minimal ___ due to minuscule ___ effects.

cardiac reserve, inotrope

Unlike most induction drugs, Etomidate may stimulate ___ ___ centers that respond to CO2, making it a useful induction agent when spontaneous ventilation is desired.

medullary ventilatory

With Etomidate, myoclonus, dystonia and tremor occur in ___ % of non-premeditated patients.

The specific enzyme that is inhibited by etomidate that causes adrenal-cortical suppression is what?

1-beta-hydroxylase(last 4-8 hours after induction dose)

Etomidate is a bad drug for those needing preserved cortisol response such as patient with ___ or in ___.

bleeding | sepsis

Ketamine, what type of chemical structure is it?

phencyclidine derivative(similar to PCP)

T or F, Ketamine gives skeletal muscle rigidity, intense analgesia, emergence delirium(possible) and be non communicative despite a wakeful look.

True

Is Ketamine a racemic mixture?

yes

T or F, Ketamine S isomers have greater analgesia properties, metabolize faster, and have a less incidence of emergence delirium.

True

T or F, Ketamine increases uptake of catecholamines into post-ganglionic sympathetic nerve endings like cocaine?

False, inhibits

What receptors do Ketamine act on?

``` N-methyl-D-aspartate opioid monaminergic muscarinic voltage sensitive calcium channels(everything but GABA) ```

Does Ketamine have analgesic properties?

Yes it is a potent analgesic

Ketamine is partially antagonized by ___?

Physiostigmine

How is Ketamine metabolized?

High hepatic clearance(1/2 time of 2-3 hours) | Metabolized by hepatic microsomal enzymes including demethylation by cytochrome P-450 to form norketamine.

Ketamine causes ___ in ICP?

increases

When administrating Ketamine, does a patient maintain their pharyngeal/laryngeal reflexes?

yes

Ketamine is not for patients with CAD, sympathomimetic function ___ myocardial oxygen needs.

increases

Ketamine is useful in asthmatic inductions due to ___.

bronchodilation

Can you use Ketamine on patients prone to malignant hyperthermia?

yes

If you use Ketamine in a patient with head injury, what must you do?

hyperventilate

The number one mechanism of action for greater cardiovascular effects with Ketamine is what?

greater sympathetic nervous system outflow

Does Ketamine significantly depress ventilation?

No, it does not significantly depress ventilation

What effect does Ketamine have on non-depolarizer relaxants?

enhances the effects of non-depolarizers

Ketamine is known for visual, auditory, proprioceptive, confusional hallucinations and dreams due to depression of what?

due to depression of the inferior colliculus and medial geniculate nucleus

Emergence delirium is increased for those over ___ years old, ___, doses over ___ mg/kg, and ___.

15 women 2 psychiatric illness history

What is the BGP of Isoflurane?

1.46

What is the BGP of Nitrous Oxide?

0.46

What is the BGP of Desflurane?

0.42

What is the BGP of Sevoflurane?

0.69

The Oil Gas Partition parallels what?

It parallels anesthetic potency and the MAC value

What is the minimum alveolar concentration of anesthetic required to prevent skeletal muscle movement in response to a supra maximal painful stimulus in 50% of patients.

MAC; movement does not correlate will with awareness

What is the MAC value of Isoflurane?

1.17 %

What is the MAC value of Desflurane?

6.6 %

What is the MAC value of Sevoflurane?

1.8 %

What is the MAC value of Nitrous Oxide?

104 %

What is the % of metabolism for Sevo?

What is the % metabolism for Nitrous?

.004

What is the % metabolism for Iso?

0.2%

MAC value for Iso?

1.2%

At what dose does Iso lead to apnea?

2 MAC

What is the MaC BAR of iso?

1.3 MAC

Can Iso cause post-anesthesia hepatitis?

yup