pharmacology: anesthesia Flashcards
what are the inhaled anesthetics?
nitrous oxide and halothane
which inhaled anesthetic is more potent? why?
halothane - lower MAC value (minimal alveolar anesthetic concentration)
which inhaled anesthetic has the lower blood-gas ratio, minimal CV effects, and no metabolism?
Nitrous oxide
side effects of halothane
malignant hyperthermia, hepatitis, cardiac arrhythmias
what are the IV anesthetics?
thiopental, midazolam, propofol, fentanyl, ketamine
thipental - use in anesthesia
barbiturate used for induction of anesthesia - lipid soluble so has rapid onset and short acting
midazolam - use in anesthesia
benzo used for preoperative sedation, anterograde amnesia, induction, outpatient surgery
propofol - use in anesthesia
used for induction and maintenance and also as an antiemetic
which IV anesthestic looks like milk
propofol
fentanyl- use in anesthesia
opiate - induction and maintence of anesthesis - depresses respiratory function
ketamine - use in anesthesia
NMDA-receptor antagonist
dissociative anesthetic used for induction of anesthesia, causes hallucination and CV stimulation and increased intracranial pressure
what are the local anesthetics groups?
esters (procaine, cocaine, benzocaine) and amides (lidocaine, bupivacaine, mepivacaine)
problem with esters
slow/fast metabolizers
problem with amides
liver function
which nerve fibers are most sensitive to local anesthetics?
smaller diameter
type B&C > type A delta > type A beta and gamma > type A alpha
what are local anesthetics administered with?
alpha 1 agonists
side effects of local anesthetics?
neurotoxicity, CV toxicity, allergies (esters via PABA formation)
why you use the alpha 1 agonists
which local anesthetic does not need an alpha 1 agonist?
cocaine - has its own vasconstriction by blocking NE reuptake
what are the skeletal muscle relaxants?
nondepolarizing (atracurium and mivacurium)
depolarizing (sccinylcholine)
how do the nondepolarizing skeletal muscle relaxants works? (atracurium and mivacurium)
nicotinic antagonists causing progressive paralysis - only effect NM receptors so no cardiac, smooth muscle, CNS effects
atracurium uses
safe in hepatic or renal impairment
have spontaneous inactivation to laudanosine which can cause seizures
mivacurium uses
very short duration - metabolized by plasma cholinesterases
what is the depolarizing skeletal muscle relaxant? mechanism and use?
succinylcholine - nicotinic agonist
depolarization and desensitization
hydrolyzed by pseudocholinesterase so have short duration
what are the centrally acting skeletal muscle relaxants?
benzos (GABA A receptors) baclofen (GABA B receptors)
used in spasticity
