Induction agents (non-barb and non-benzo) Flashcards
Which induction agents reduce ICP?
propofol, thiopental, and etomidate
Which induction agent raises ICP?
ketamine
Which induction agent has no effect on ICP?
precedex
Two common side effects seen during emergence from ketamine.
combativeness and delirium
Ketamine (Kerolar) produces this type of anesthesia.
dissociative (the thalamus is dissociated from the limbic cortex. sound and vision are mixed up)
Ketamine (Kerolar) induction dose, onset, peak, duration?
dose: 1 - 2 mg/kg IV; 3 - 5 mg/kg IM
onset: 30 seconds
peak: does not peak
duration: 5 - 15 minutes
Ketamine’s mechanism of action?
- N-methyl-D-aspartate (NMDA) antagonist - blocks ion (calcium/sodium/potassium) channel of the receptor inhibiting depolarization
- muscarinic agonist
- D-opioid agonist (weak)
- sodium and calcium channel blocker
Does ketamine (Kerolar) increase or decrease arterial blood pressure, heart rate, and cardiac output?
increase
Due to ketamine’s effects on the cardiovascular system, its use should be avoided in patients with these diagnoses.
coronary artery disease, uncontrolled hypertension, congestive heart failure, and arterial aneurysms
Large doses of this medication cause direct myocardial depression.
ketamine
Ketamine (Kerolar) has _______ stimulatory effects on the sympathetic nervous system.
indirect
Is ketamine (Kerolar) a bronchoconstrictor?
no, it is a potent bronchodilator. it is a good induction agent for asthmatic patients.
T or F, ketamine (Kerolar) causes increased salivation?
true
This medication is the closest thing to being a “complete” anesthetic, as it induces analgesia, amnesia, and unconsciousness.
ketamine
This medication attenuates ketamine’s cardio-stimulatory effects and prolongs its elimination half-life.
diazepam
Etomidate (Amidate) induction dose, onset, peak, duration?
dose: 0.2 - 0.5 mg/kg IV
onset: 30 seconds
peak: 1 minute
duration: 3 - 10 minutes
Propofol (Diprivan) induction dose, onset, peak, duration?
dose: 1.5 - 2.5 mg/kg IV
onset: 30 seconds
peak: 1 minute
duration: 5 - 10 minutes
Propofol (Diprivan) initial and maintenance dose using either the infusion or bolus method?
- infusion method
initiation dose: 100 - 150 mcg/kg/min over 3 - 5 min
maintenance dose: 25 - 75 mcg/kg/min - bolus method -
initiation dose: slow injection 0.5 mg/kg over 3 - 5 min
maintenance dose: incremental doses of 10 or 20 mg
per the drug card
Etomidate’s mechanism of action
- GABA receptor agonist (binds to beta-subunit of GABA receptor, increasing its affinity for GABA)
- GABA causes an influx of chloride in the post-synaptic neurons, hyperpolarizing the cell, and making it less responsive to neurotransmitters
What is the name of the active metabolite of ketamine?
norketamine (it is an active metabolite, but is less potent than ketamine)
Long-term infusions of etomidate (Amidate) can lead to this?
adrenocortical suppression (induction doses of etomidate transiently inhibit enzymes involved in cortisol and aldosterone synthesis)
How is etomidate (Amidate) metabolized?
by hepatic enzymes and plasma esterases
Etomidate (Amidate) can cause sudden, generalized, asynchronous muscle contractions known as what?
myoclonia
Propofol’s (Diprivan) mechanism of action?
- GABA receptor agonist (binds to beta-subunit of GABA receptor, increasing its affinity for GABA)
- GABA causes an influx of chloride in the post-synaptic neurons, hyperpolarizing the cell, and making it less responsive to neurotransmitters
Is the pH of propofol hypertonic, isotonic, or hypotonic?
isotonic (7.0 - 8.5)
Is propofol contraindicated in patients with an egg allergy?
no
What percentage of propofol is protein bound?
98%
Potentiation of effects will be seen when propofol is given with these two types of medications…
sedatives and narcotics
T or F, propofol has antipruritic and antiemetic effects?
true
How is propofol metabolized?
mostly hepatic, some pulmonary
excreted by kidneys
The major cardiovascular effect of propofol is a decrease in what? (and this is due to what three things?)
arterial blood pressure (due to a drop in systemic vascular resistance [inhibition of sympathetic vasoconstricor activity], cardiac contractility, and preload)
Propofol depresses the body’s normal response to? (pulmonary in nature)
hypercarbia
Propofol should be used cautiously in these patient populations…
sulfite allergy (new formulation has sulfite ingredient), hypovolemic (d/t decreased SVR + inotropy), cardiac issues (fixed CO - aortic stenosis), or elderly
How does etomidate’s short duration of action differ from propofol’s short duration of action?
etomidate is metabolized by esterases. propofol is rapidly redistributed.
Is ketamine a weak acid or base?
weak base
Is propofol a weak acid or base?
weak acid
Ketamine is a structural analogue of…
phencyclidine
How is ketamine (Kerolar) metabolized?
hepatic
Ketamine (Kerolar) is useful in these situations…
- in c-section for abruption, placenta previa, and as supplement to bad blocks
- in burn patients for dressing changes
Etomidate (Amidate) cardiac effects.
none, it is cardiac stable
it’s good for hypovolemia, trauma, stenosis, and heart failure
Does etomidate (Amidate) release histamine?
no
