Week 4: Anesthetics Flashcards
Local anesthetics directly affect the voltage sensitive _____ ___, _______ the permeability of the excitable membranes to ____.
Na+ channels
decreasing, Na+
What are the local anesthetic esters? (3)
Procaine
Chloroprocaine
Tetracaine
What are the local anesthetic amides? (6)
Mepivacaine Bupivacaine LIdocaine Prilocaine Ropivacaine Levobupivacaine
What is the onset and duration of Procaine?
Onset :2-5 minutes
Duration: 0.25-1 hour
What is the onset and duration of Bupivacaine?
Onset: 5 minutes
Duration: 2-4 hours
What is the onset and duration of lidocaine?
Onset: <2 minutes
Duration: 0.5-1 hr
What is the result of the aromatic ring structure?
increased lipid solubility
What determines the type of metabolism?
linkage
What linkage involves hepatic metabolism?
Amides
What linkage involves plasma esterases?
Esters
What influences aqueous solubility?
Terminal amine
What is the effect of lidocaine combined with a vasoconstrictor (epinephrine)?
constriction of surrounding blood vessels to keep anesthetic in contact with nerve.
causes prolonged duration of action and also controls bleeding
What is the max dose of lidocaine?
Lidocaine 2%
7mg/kg
total: 500
What is the most commonly used anesthetic?
Lidocaine
What anesthetic has a shorter duration of action compared to lidocaine?
Procaine
What anesthetic has a higher potency compared to lidocaine?
Bupivacaine
What is the maximum of lidoderm patched?
3 patches/daily
True allergies are ____.
rare
What type of local anesthetics are more common to cause allergic reaction?
more common with ester type
*if allergic to one, allergic to all
What is a systemic effect of local anesthesia?
death by respiratory depression
seizures!
What is the local anesthetic used in epidurals?
bupivacaine
EMLA is a topical cream with a combination of what?
lidocaine and prilocaine
What population are EMLA useful?
in pediatrics
What are the common uses for EMLA? (3)
starting IVs, biopsies
venous, arterial, finger, heel and lumbar punctures
removal of staples, sutures and lines
What toxicology emerged with chloroform use?
long term liver damage and sudden death
What toxicology emerged from methoxyflurance?
nephrotoxic
What was the problem that emerged from ether?
too flammable
What is a side effect of inhaled nitrous oxide?
increased post op N&V
What is a side effect of inhaled halothane (fluothane)?
hepatotox, arrhythmias
What is a side effect of inhaled enflurane (ethrane)?
hepato & renal toxicities
What is a common side effect of inhaled isoflurance (Forane)?
coronary steal- shunting of blood away from already ischemic myocardium
What is a common side effect of inhaled desflurane (soprane)?
tachycardia
What is a common side effect of sevoflurane (ultane)?
toxic metabolites
What are the advantages of inhalation anesthesia?
completely painless induction of anesthesia
No IV access
most rapid appearance of blood in arterial blood.