General Anesthetics Flashcards
5 tenets of anesthesia
analgesia, amnesia, atonia, altered ANS, hypnosis
2 primary mechanisms of action
1) inhibit NMDA-r- ketamine, N2O; 2) potentiate GABA-r- barbiturates, benzodiazepines, propofol, etomidate, volatile fluranes
isoflurane, desflurane, sevoflurane
vapors/potent agents= complete anesthetic; low PP needed (<7%)
minimal alveolar concentration (MAC)
concentration at which movement is inhibited in 50% of patients; corresponds to POTENCY
blood: gas partition coefficient
corresponds to RAPIDITY OF ONSET and OFFSET (induction/emergence)
nitrous oxide
needs high PP (108%), high MAC and NOT potent; expands rapidly in N2 (do not use w/ pneumothorax); sedative or adjuvant use
isoflurane
complete anesthetic; low PP needed; increases cerebrovascular blood flow and ICP (do not use with epidural hematoma)
desflurane
complete anesthetic; low PP needed; airway irritant; most rapid onset/offset
sevoflurane
complete anesthetic; low PP needed; NEWl CV stable
dantrolene
blocks ryanodine Ca2+ receptor; tx for malignant hyperthermia
total IV anesthesia agents
propofol, etomidate, ketamine
propofol
‘milk of amnesia’, lipid soluble, rapid onset; patients wakes up alert, no N/V; side fx: hypotension, negative inotropy
etomidate
rapid onset/offset, does not increase ICP; side fx: adrenal suppression, post-op N/V
ketamine
provides analgesia and amnesia (dissociative); increases ICP
drug-induced liver injury
“halothame hepatitis”; autoimmune, F>M, obesity; 1-3wk post-exposure
