Anesthetics Flashcards
what is the role of sedation
facilitation of painful procedures
what is the spectrum of sedation
- anxiolysis -> moderate sedation -> deep sedation -> anesthesia
what are the neurophysiologic effects produced by anesthetics
- unconsciousness
- amnesia
- analgesia
- inhibition of autonomic reflexes
- skeletal muscle relaxation
what is the perfect anesthetic
- optimize performance of procedure
- minimize patient movement
- maximize patient comfort
- no side effects
- provide sedative/hypnotic effect, analgesia, amnesia
- minimal cardiovascular and respiratory effects
- rapid onset, short acting or reversible
describe etomidate
- hypnotic, no analgesia
- 0.3mg/kg IV
- each 0.1mg/kg = 100 sec sedation
- onset within seconds
- RSI gold standard, minimal use in procedural sedation
- neutral hemodynamic profile
- myoclonic activity
- EEG activity increased
- emetogenic
what is the downfall of etomidate
- inhibits 11 beta - hydroxylase
- cholesterol -> cortisol
- adrenal suppression
describe benzodiazepines
-midazolam
- most lipid soluble
- slower, unreliable, difficult to titrate
- better suited as anxiolytic
- great amnesia, no analgesia
what is the reversal agent for benzos
flumazenil
describe propofol
- GABA agonist
- quick on, quick off
- lipid emulsion
- no analgesia
- burns on administration 0 may give lido 2-4ml of 1%)
- negative inotrope
- respiratory depression
what is the dosage of propofol
- 1mg/kg IV followed by 0.5 mg/kg IV
- anesthesia: 2-3mg/kg induced then max 200 mcg/kg/min for maintenance
- sedation for mechanical ventilation: max 75 mcg/kg/min
describe ketamine
- similar to PCP: less euphoria and sensory distortion
- dissociative anesthetic: corticothalamic and limbic dissociation
- bronchodilation, airway reflexes maintained
what are the mechanisms of ketamine
- GABA
- mu receptor agonist
- catecholamine reuptake inhibition
- cholinergic receptor antagonism in prefrontal cortex
- NMDA receptor antagonism
what are the dosages of ketamine
- analgesia: 0.1-0.5mg/kg IV
- tweener zone: 0.6-0.9 mg/kg IV
- dissociation: 1mg/kg and up IV
- dissociation 4-6mg/kg IM
- can also administer intranasally
what are the indications for ketamine
- sedation, analgesia, anesthesia
- seizure
- depression
- excited delirium
- opioid induced hyperalgesia
- opioid sparing treatment
- delayed sequence intubation
what are the adverse reactions of ketamine
- sympathomimetic: can be good or bad
- psychic phenomena: emergency vs dysphoria
- intracranial pressure
describe ketofol
- ketamine + propofol
- 1:1 most common
- 20mL syringe; 10mL propofol and 10mL of ketamine, note concentration!
- dosing typically 0.5mg/kg of each component
- 0.1 mL/kg
what are the side effects of propofol
- respiratory depression
- hypotension
- no analgesia
- amnesia
- GABA
what are the side effects of ketamine
- bronchodilation, airway reflexes maintained
- increased blood pressure
- analgesia
- minimal amnesia
- emergency reactions
describe dexmedetomidine
- highly selective alpha-2 agonist
- same family as clonidine
- sedation, some analgesia, opioid sparing, sympatholytic
- easily arousable, minimal respiratory depression
- onset 15 minutes
- context sensitive half life: 4 minutes after 10 minute infusion, 250 minutes after 8 hour infusion
- may accumulate in hepatic dysfunction
what is the dosing for dexmedetomidine
- load: 0.5-1mcg/kg over 10-15 min
- infusion: 0.2-0.7mcg/kg/hour
what are the adverse effects of dexmedetomidine
- bradycardia
- hypotension
