What are the 4 functions of Vasoconstrictors? blood vessels at site = decrease dose of LA increase of LA = 6 times as long Provides at injection site decrease rate of LA = decrease risk of toxicity.
All LA are vasoconstrictors.
All LAs are vasodilators.
The two types of vasoconstrictors used in the US are:
Epinephrine, levonordfrin, both, neither.
are absorbed from injection site into bloodstream. are unstable in solution.
is the preservative added for stability. About 10% of asthmatics are allergic.
Epi in LAs have identical structure to the natural hormone.
Epinephrine targets these two groups of receptors located in most tissues:
Alpha receptors: ;
beta receptors: ; ; .
high levels of epi - ❌ receptors override ❌ receptors = vasoconstriction
❌ levels of epi - beta receptors override alpha receptors = ❌.
concentrations of vasoconstrictors in LA solutions are referred to as a ratio of of epi per of solution.
The highest concentration of epi available in the US is 1: This is only used for --> usually via .
Rebound vasodilation occurs after hours and the receptors are prominent.
Rebound vasodilation occurs during the concentrations of epi are used
The lowest concentration of epi available in the US is . Lower the concentration is Produces side effects
Levonordefrin is only % as potent as epi Only available in US as concentration in 2% / The 1:20,000 has the same clinical effect as epi
Epi affects alpha receptors % and beta receptors % Levonordefrin affects the alpha receptors % and the beta receptors %.
compared to epinephrine, levonordefrin has the same cardiac affects like increased HR, stroke volume, CO, increased dysrhythmias, and dilating of coronary arteries but to a degree.
Levonordefrin is a great choice of LA with vasoconstrictor because blood sugar increase is to a degree.
causes potent bronchodilation to a lesser degree and less hemostasis
Both epi and levonordefrin have sodium bisulfite
EPI MRD healthy: mg CV ds: mg
Levonordefrin MRD healthy: mg CV ds: mg
OD occurs via injection administering more than
symptoms will occur within seconds body clears drug within - minutes via
