Term
| How are local anesthetic pKa and speed of onset related? |
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Definition
| LA's are weak bases. When placed in the human body at 7.4, the more non-ionized present the faster it will work.....the lower the pKa, the more unionized will be present and the faster it will work |
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Term
| What determines local anesthetic potentcy? |
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Definition
| Lipid solubility (more lipid soluble = more potent) |
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Term
| What property is most responsible for duration of action? Second most? |
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Definition
| Degree of protein binding is most important, while lipid solubility is second (the more protein bound, the longer it lasts, the more lipid soluble = the longer it lasts) |
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Term
| What two locals have very little protein binding? |
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Definition
| Procaine and chloroprocaine (less than 10% for both) |
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Term
| How many nodes of Ranvier must be blocked in order to stop nerve conduction in myelinated nerves? |
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Definition
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Term
| Which form of local anesthetic is needed for nerve block? |
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Definition
| Both ionized and un-ionized. Un-ionized to cross the membrane and ionized to bind to the Na receptor sight |
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Term
| What are the toxic levels of lidocaine and at each level what happens? |
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Definition
3--circumoral and tongue numbness
4--lightheaded/visual disturbances
10-unconsciousness
26-CV collapse |
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Term
| What is a normal dibucaine number? |
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Definition
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Term
| What is the range of pKa for local anesthetics? |
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Definition
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Term
| What determines local anesthetic speed of onset? |
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Definition
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Term
| What part of the nerve cell do local anesthetics work on? |
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Definition
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Term
| Which local anesthetic can lead to development of methemoglobinuria? |
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Definition
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