Anesthesia Flashcards
what do local anesthetics work on?
Na channels
two types of local anesthetics
esters and amides (all of the amides have i’s in them)
aromatic ring
inc’s lipid solubility
linkage
determines type of metabolism
amides: hepatic
esters: plasma esterases
terminal amine
influences aqueous solubility
lidocaine with epi
controls bleeding
lidocaine
most widely used local anesthetic
all have comparable efficacy though
500 mg/10 mg/mL max lidocaine = 50 mL of 1% lidocaine
1% solution of local anesthetic =
10 mg/mL
lidoderm
lidocaine patch 5% topical
on 12 hrs - off 12 hrs
may be cut to size (unlike most transdermals)
max 3 patches/day
hypersensitivity to local anesthetics
true allergies are rafre
more common with ester type
if allergic to one, allergic to all esters - switch to amide (or vice versa)
what local anesthetic is in epidurals?
bupivacaine
EMLA
used for starting IVs/, biopsies
venous, arterial, finger, heel and lumbar punctures
general anesthetic toxicity emergencies
chloroform (long term liver damage and sudden death), methoxyflurane (nephrotoxic)
ether (too flammable)
Halothane
hepatotoxic and arrhythmia
Enflurane
hepato and renal toxicities
general anesthesia safety
as long as patient is breathing satisfactory
adv of inhalation anesthesia
completely painless, no IV access, rapid
rates of PONV for inhalation anesthetics
all pretty similar
differences between inhaled anesthetics
metabolism and effects on heart
indications for sedatives
facilitate tolerance to procedures
red unnecessary recall
mandatory adjunct to neuromuscular blockade
diazepam
propylene glycol vehicle
sig accumulation with repetitive dosing
3 active metabolites in diazepam (name 1)
desmethyldiazepam (T1/2 = 100-200 hrs)
lorazepam
continuous infusion may cause propylene glycol-induced metabolic acidosis
for anxiety/sedation in adults: preprocedural anxiety (PO) 1-2 mg 1 hr prior
Midazolam
least lipid soluble
drug interactions - metabolized by CYP3A4 (hepatic)
renally eliminated
metabolized in liver to active metab
