Lecture 4/10 Flashcards
What are the major classes of local anesthesia?
amide, ester
What is a local anesthetic?
a substance which reversibly inhibits nerve conduction when applied directly to tissues at non-toxic concentrations
What is the mechanism of action of local anesthetics?
Limit influx of sodium, therby limiting propagation of the action potential
Which local anesthetics are esters?
cocaine, chloroprocaine, procaine, tetracaine
Which local anesthetics are amides?
Bupivacaine, lidocaine, ropivacaine, etidocaine, mepivacaine
What are the signs of systemic toxicity of local anesthetics?
lightheadedness, tinnitus, seizures, CNS/cardiovascular collapse, and cardiac arrest
What is the treatment of systemic local anesthetic toxicity?
intralipid 20% 1.5 mL per kg initially then repeated or start infusion
Vasoconstrictors should not be used in which locations on the body?
fingers, toes,nose, ear lobes, and penis
What are the types of regional anesthesia?
topical, local/field, intravenous block (Bier block), peripheral (named) nerve, plexus, central neuraxial
What is an IV block used for?
any surgical procedure on an extremity
What are the major kinds of neuroaxial blocks?
subarachnoid (spinals) and epidural
For which neuroaxial block should you have cerebrospinal fluid return through the needle?
spinal block (subarachnoid)
What tissue layers are penetrated for an epidural block?
skin, subcutaneous, supraspinous ligament, interspinous ligament, ligamentum flavum
What are the potential complications of both a spinal or epidural block?
post-dural puncture headache (This would be an accident in the epidural block. You shouldn’t puncture the dura for this.), hypotension, bradycardia, cardiac/pulmonary arrest
Which requires a lower dose of local: epidural or spinal block?
spinal
