Anesthetics Flashcards
What is the MOA of local anesthetics?
Directly affects sensitive Na+ channels
What are two types of local anesthetics?
Esters
Amides
What are some amide local anesthetics?
Mepivacaine Bupivacaine Lidocaine Prilocane Ropivacaine Levobupivacaine *note the i in each*
What is an example of an ester local anesthetic?
Procaine (novacaine)
What is the onset time of procaine and how long does it last?
2-5 minutes
.25-1 hour
What is the time of onset for bupivacaine and how long does it last?
5 minutes
2-4 hours
What is the time of onset of lidocaine and how long does it last?
< 2 minutes
.5-1 hours
What does the aromatic ring structure do for local anesthetics?
Increased lipid solubility
What does the linkage structure do for local anesthetics?
Determines the type of metabolism
What kind of metabolism do amide local anesthetics have?
Hepatic metabolism
What kind of metabolism do ester local anesthetics have?
Plasma esterases metabolize
What do terminal amines do for local anesthetics?
Influence aqueous solubility
Why do you combine lidocaine with?
Epinephrine
What is lidocaine with epinephrine and what are the advantages of it?
Vasoconstrictor
Prolongs duration of action
Controls bleeding
What is the max dosage of lidocaine 2%?
7 mg/kg
Total = 500 mg
What concentration of procaine has a shorter duration of action?
10%
Which percentage of bupivacaine is most commonly used?
0.25%
What local anesthetic is most widely used?
Lidocaine
Is the efficacy comparable between all local anesthetics?
Yes
What is the “dosage” of 1% solution equivalent to?
10 mg/mL
What is the max dosage of lidocaine and its concentration?
50 mL of 1%
What is a patch used as local anesthetic?
Lidocaine patch 5% topical
How do you administer the lidocaine patch?
On 12 hours
Off 12 hours
Can you cut the lidocaine patch?
Yes -> different from other transdermal systems
What is the max amount of patches that can be used per day?
3 patches
Are true allergies to local anesthetic common or rare?
Rare
Which type of local anesthetic MC has allergic reactions?
Ester type
If allergic to 1 ester, can you take others?
No, allergic to 1 allergic to all
Switch to amide
What are systemic effects of local anesthesia?
Respiratory depression (death) Seizures
What anesthetic is commonly used in epidurals?
Bupivacaine
What is EMLA?
Eutectic mixture of local anesthetics
What do you combine for EMLAs?
Lidocaine
Prilocaine
What population doe you used EMLAs with?
Pediatrics
What do we use EMLAs for?
Starting IVs
Bx
Venous, arterial, finger, heel, and lumbar punctures
Removal of staples, sutures, and lines
What were the emergent toxicities of general anesthetic chloroform?
Long term liver damage
Sudden death
What was the emergent toxicity of general anesthetic methoxyflurane?
Neprhotoxicity
What was the problem with general anesthetic ether?
Too flammable
What is a problem with nitrous oxide (inhaled)?
Increased post-operative nausea and vomitting
What is a problem with halothane (inhaled)?
Hepatoxicity
Arrhythmias
What is a problem with enflurane (inhaled)?
Hepato and renal toxicities
What is a problem with isoflurane (inhaled)?
Coronary steal
shunting of blood away from already ischemic myocardium
What is a problem with desflurane (inhaled)?
Tachycardia
What is an issue with sevoflurane (inhaled)?
Toxic metabolites
When is elimination of an agent and emergence from anesthesia essentially guaranteed?
As long as breathing is satisfactory
What are some advantages of inhalational anesthesia?
Completely painless induction
No IV access
Most rapid delivery to blood stream
How are the rates of PONV in all generalized inhalation anesthesias?
They are all similar
What are the two main differences between inhalational anesthetics?
Metabolism
Effects on the heart
