Hypnotics Flashcards
Propofol : Class
Hypnotic
Propofol : Uses
Induction
General Anesthesia
MAC
Propofol : Mechanism of Action
Mimics GABA at the receptor, directly activating chloride channels, which hyperpolarizes the postsynaptic membrane
Propofol : Dose
Induction: 1-2.5 mg/kg
Maintenance of GA:
25-300 mcg/kg/min
Sedation:
25-100 mcg/kg/min
Antiemetic:
10 mcg/kg/min
Propofol : Pharmacokinetics
Absorption: IV
Onset: 30 seconds
DOA: 5-15 minutes
Metabolism: Hepatic and extra hepatic (Lungs)
Excretion: Kidneys
Propofol: Contraindications
Hypersensitivity
Propofol : Considerations
No analgesia
Decreases BP
Painful on injection
Risk for thrombophlebitis
Propofol Infusion syndrome risk with high doses
Etomidate : Class
Hypnotic
Etomidate : Uses
Induction (CV stability/Trauma)
Etomidate : Mechanism of Action
Binds to the GABA-a receptor
Low dose-potentiates GABA
Higher dose- direct GABA stimulation
Etomidate : Dose
0.3mg/kg
Etomidate : Pharmacokinetics
Absorption: IV
Onset: 1 minute
Duration: 5-15 minutes
Metabolism: Hepatic and PLASMA ESTERASES
Excretion: Kidneys
Etomidate : Contraindications
Hypersensitivity
History of Porphyria
Etomidate : Considerations
No analgesia
Increased risk of N/V
Inhibits Cortisol (adrenal suppression)
Ketamine : Class
Phencyclidine Derivative
Ketamine : Uses
Analgesia
Anesthetic
Antidepressant
Ketamine : Mechanism of Action
Non-competitive antagonist at NMDA receptor ion channels.
Ketamine blocks the opening of channels, inhibiting the excitatory response to glutamate.
Provides amnesic and potent analgesia.
Produces a “dissociative state” by depressing the cerebral cortex and thalamus and stimulating the hippocampus.
It also binds with opioid, MAO, serotonin, NE, muscarinic and sodium channels
Ketamine inhibits neuronal sodium channels (producing a modest local anesthetic action) and calcium channels (causing cerebral vasodilatation)
Ketamine : Dose
IV Induction- 2mg/kg
IM Induction- 4mg/kg
Sedation-
1-3 mcg/kg/min
Multimodal Infusion-
5 mcg/kg/min
Ketamine : Pharmacokinetics
Absorption: IV, IM, Intranasal
Onset:
IV - 2 minutes
IM - 20 minutes
Duration: 10 minutes
Metabolism: P450 enzymes in liver
ACTIVE METABOLITE: Norketamine
Excretion: Kidneys
Ketamine : Contraindications
HTN
Increased Intracranial pressure
History of emergence delirium
Ketamine : Considerations
Can have dissociative effects (pair with benzodiazepine)
Analgesic effects
SNS Stimulant - Increases BP/HR/CO in most patients
Increased Secretions (Pair with glycopyrrolate)
Bronchodilator
Active metabolite that is really excreted.
Dexmedetomidine : Class
Selective alpha2 adrenergic agonist
Dexmedetomidine : Uses
MAC
Induction
Analgesia
Prevent emergence delirium
Dexmedetomidine : Mechanism of Action
Central and peripheral alpha 2 adrenergic receptor agonist.
Inhibits Norepinephrine release.
Decreases levels of sympathetic outflow from the CNS.
Dexmedetomidine : Dose
Sedation: 1 mcg/kg over 10 minutes then 0.2-1 mcg/kg/hr
Dexmedetomidine : Pharmacokinetics
Absorption: IV, IM, Intrathecal, Epidural
Onset: 5 minutes
Duration: 2 hours
Metabolism: Hepaticly via P450 system
Excretion: Liver
Dexmedetomidine : Contraindications
Hypersensitivity
Bradycardia and Hypotension
Dexmedetomidine : Considerations
Analgesic properties
Reduces emergence delirium
Hypotension and Bradycardia
Midazolam : Class
Hypnotic
Midazolam : Use
Sedative
Anxiolytic
Anticonvulsant
Midazolam : Mechanism of Action
Enhances the response to the GABA A receptor
Midazolam : Dose
Premedication:
IV-2mg
PO- .5mg/kg
Induction:
0.3mg/kg
Midazolam : Pharmacokinetics
Absorption: PO, IV, IM, Intranasal
Onset: 1 minute
Duration: 15 minutes
Metabolism: Hepaticly via CYP 450 system
ACTIVE METABOLITE: 1-hydroxymidazolam
Excretion: Kidneys
Midazolam : Contraindications
Elderly- associated with post-op delirium
Midazolam : Considerations
Active metabolite that is really excreted
Associated with post-op delirium in the elderly
Anterograde Amnesia
Decreases CO2/Hypoxia response
No analgesia
