General and Local Anesthetics Flashcards
General Anesthesia
reversible response of depression of CNS function resulting in loss of function and perception of external stimuli
Local anesthetics
lidocaine, bupivicaine, ropivacaine, cocaine, benzocaine
General anesthetics
halothane, enflurane, isoflurane, desflurane, sevoflurane, NO
IV anesthetics
barbiturates, etomidate, ketamine, propofol
Several anesthesia considerations
Amnesia, immobilty, attenuation of response to noxious stimuli, analgesia, unconsciousness
Local Anest.
hydrophilic and lipophilic lipophilicity increases potency and duration of action (amides have two i’s in the name, esters do not)
Local Anest.
hydrophilic and lipophilic lipophilicity increases potency and duration of action (amides have two i’s in the name, esters do not)
Local Anesthesia MOA
decrease conduction at cell membrane, reduce or prevent Na permeability, leads to loss of sensation in the area supplied by nerve
Local anesthesia MOA cont’d
anesthesia molecule gains access when the channel is open, stabilizes the inactive state, more blockage produced in highly stimulated nerves
Routes
Surface: Topical, Infiltration: injected under surface, Conduction: deep injection (drug bathes nerve itself), Spinal
Amides
biotransformed by liver enzymes, longer acting
Duration of action of Local anest.
dependent upon- blood flow, temp. affects blood vessel size, protein binding (the stronger the bond between drug and protein on Na channel the longer the duration
Local anest. and use with vasoconstrictor
ie. epinephrine, vasoconstriction, decr. systemic absorption, localized action, incr. duration of action (all local anest. are vasodilators except cocaine)
Buffered lidocaine
NaHCO3 decreases pain at injection site, shortens onset, decreased stability, ph to 7.2-7.4
Bupivicaine
more potent and longer acting than lidocaine, preferred for longer procedures
ADE
dose related toxicity, Excitation- tachycardia/tremors, Depression-circulatory shock, respiratory depression
General Anesthesia
generalized loss of felling or sensation accompanied by loss of consciousness during which surgery can be performed (no loss of consciousness with local anesthesia)
Progression of Anesthesia
Induction, Maintenance, Emergence
Mechanism of general Anesthesia
hyperpolarization of neurons, reduce synaptic transmission (pre-synaptic or post-synaptic)
Molecular Targets of General Anest.
increase sensitivity of receptor to GABA, Inhibition of glutamate receptors (ketamine/NO)
Inhaled Anest.
for maintenance of anesthesia, low TI in and out of lungs
NO
weak anesthetic, gas, increased post-op NV
Fluorinated Hydrocarbons
use via vaporizer, combined with NO, Very strong, increased stability, decreased toxicity, ADE-respiratory depression and malignant hyperthermia
Isoflurane
most potent of the volatile anesthetics, high solubility, odorous
