Lecture Notes Flashcards
1
Q
LA:
- Potency
- Speed of onset
- Duration
A
Potency = lipid solubility / hydrophobicity
Speed of onset = pKa / pH
Duration = protein binding
2
Q
Effects of adding epinephrine to LA
A
- Increase duration (decreased vascular uptake)
- Marker for IV injection
- Decrease LAST risk (decreased vascular uptake)
3
Q
Side effects of adding epi to LA
A
- Possible local/neural ischemia
- HTN/arrhythmias if vascular
4
Q
Effect of adding opioids to neuraxial
A
- Central mu receptors -> attenuation of C fiber nociception -> denser and maybe longer block
5
Q
Limits of opioids w/ LAs
A
- No evidence for regional/peripheral use
- Chloroprocaine may decrease opioid effectiveness
6
Q
MOA of clonidine w/ LAs
A
- Direct inhibition of nerve firing
- Analgesia via CNS adrenergic receptors
7
Q
Effects of adding clonidine to LAs
A
- Decreased LA dose needed
- Prolonged duration
8
Q
Limits of adding clonidine to LAs
A
- Hypotension
- Bradycardia
- Sedation
9
Q
Limit of adding bicarb to LAs
A
- Cannot alkalinize beyond pH 6.5-8 before it precipitates
- Maybe causes 10% decreased ionized fraction (<5 min difference)
