Propofol
The mechanism of action of propofol is
Direct GABA-A agonist -> increased Cl conductance -> neuronal hyperpolarization
Norketamine
The main key benefit of etomidate is
Hemodynamic stability
Clearance of benzodiazapines are done by
P450 enzymes (liver and intestines)
The mechanism of action of precedex is
Alpha 2 agonist -> decreased cAMP -> inhibit locus coeruleus in the pons
The CMRO2, CBF, and ICP do what after Thiopental administration
Decrease
Cerebral vasoconstriction/used to treat increased ICP/ burst suppresion
The CMRO2, CBF, and ICP do what after propofol administration
Decrease
The IM dose of ketamine is
4-8mg/kg
Myoclonus is
Involuntary skeletal muscle contractions, dystonia or tremor
In people with seizures this may increase the risk of seizures (can be used to map seizure foci)
This potentiates the respiratory affects of midazolam
What is the change in CMRO2 & CBF
Decreased CBF
unchanged CMRO2
(uncoupling)
Mechanism of action of thiopental
GABA-A agonist
Depress the reticular activating system in the brainstem
The preservative in propofol is
EDTA (disodium ethylenediamine tetraacetic acid)
These patients are not the best candidates for ketamine
Acute intermittent porphyria
This side effect is more common than with any other induction agent with etomidate
PONV
Order these benzos by potency (greatest to least)
Midazolam
Lorazepam
Diazepam
Lorazepam > Midazolam > Diazapam
How does precedex produce sedation
Decreased SNS tone
The most similar to natural sleep
Hypotenison with thiopental occurs due to
Venodilation
Decreased Preload
Non-immunologic histamine release (short lived)
Clinical presentation of propofol infusion syndrome includes
- metabolic acidosis, rhabdomyolysis, enlarged fatty liver, renal failure, hyperlipidemia, lipemia (cloudy plasma)
Is Ketamine a myocardial depressant or stimulant
Depressant
Even though there is increased SNS tone, CO, HR, SVR, and PVR; the depressant effects will be seen in patients with sympathectomy or depleted catecholamine stores (sepsis)
Etomidate chemical structure features what
Imidazole ring
-acidic pH -> ring opens ->increased H2O solubility
-physiologic pH -> closes ring-> increased lipid solubility
The mechanism of action and dose of Flumazenil is
Competitive antagonist GABA-A
Initial dose 0.2mg titrated by 0.1mg every 1 minute
Can precipitate signs of withdrawal and seizure
The effect on the thermoregulatory response from Precedex is
Impaired
An antishivering effect is produced
The most common barbiturate used in ECT (and dose)
Methohexital
1-1.5mg/kg
Fospropofol is a
Prodrug
-it is metabolized to propofol by alkaline phosphatase in the blood
Ketamine blocks central sensitization and wind up phenomenon where in the body
Dorsal horn of the spinal cord
Etomidate is an inhibitor of
11-beta-hydroxylase & 17- alpha-hydroxylase
Because of this avoid in patients that rely on the stress response (sepsis and acute renal failure). These patients need cortisol
The imidazole ring makes Midazolam ____ in the vial and _____ in the blood stream
water soluble (ionized)
lipid soluble (nonionized)
Explain how Precedex produces an analgesia effect
Alpha 2 stimulation in the dorsal horn (spinal cord) by decreasing substance P and decrease glutamate release
Substitutions on the ring of barbiturates modify the
PK/PD
Thiobarbiturates- sulfur molecule second position
Oxybarbiturates- oxygen on the second position