Other nonvolatile anesthetic agents 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 produces this type of anesthesia.
dissociative (the thalamus is dissociated from the limbic cortex. sound and vision are mixed up)
Ketamine dose - induction
1 - 2 mg/kg IV
3 - 5 mg/kg IM
Ketamine is an antagonist of what receptor?
N-methyl-D-aspartate (NMDA)
Does ketamine 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 has _______ stimulatory effects on the sympathetic nervous system.
indirect
Is ketamine a bronchoconstrictor?
no, it is a potent bronchodilator. it is a good induction agent for asthmatic patients.
T or F, ketamine 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 dose - induction
0.2 - 0.5 mg/kg IV
Propofol dose - induction
1 - 2.5 mg/kg IV
Propofol dose - maintenance infusion
50 - 200 mcg/kg/min IV
Propofol dose - sedation infusion
25 - 100 mcg/kg/min IV
Etomidate’s mechanism of action
depresses the reticular activating system and mimics the inhibitory effects of GABA (specifically it appears to bind to a subunit of the GABA type A receptor, increasing its affinity for GABA)
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 can lead to this?
adrenocortical suppression (induction doses of etomidate transiently inhibit enzymes involved in cortisol and aldosterone synthesis)
How is etomidate metabolized?
by hepatic enzymes and plasma esterases
Etomidate can cause sudden, generalized, asynchronous muscle contractions known as what?
myoclonia
Propofol mechanism of action
GABA interaction (hyperpolarization of chloride ion channels)
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 types of medications.
sedatives and narcotics
T or F, propofol has antipruritic and antiemetic effects?
true
How is propofol metabolized?
CYP450 (then the metabolites are excreted by the 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, 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
What is the onset of propofol?
30 seconds
What is the duration of propofol?
2 - 8 minutes
What is the onset of ketamine?
30 - 60 seconds
What is the duration of ketamine?
10 - 20 minutes
Ketamine is a structural analogue of…
phencyclidine
