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Article: Which Actions of Local Anesthetics Are Relevant to the Medical Care of Humans?
- Article from:
- Regional Anesthesia and Pain Medicine
- Article date:
- November 1, 2007
- Author:
CopyrightCopyright Churchill Livingstone Inc., Medical Publishers Nov/Dec 2007. Provided by ProQuest LLC. (Hide copyright information)
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For every complex problem there is a solution that is simple, neat and wrong.
- H. L. Mencken (1880-1956)
Some of the things that doctors do have simple, neat molecular explanations; most do not.
We all know the dogma for the mechanism of peripheral nerve block. If one injects 40 mL of 0.5% bupivacaine near the brachial plexus in the axilla, the fraction of sodium (Na) channels that bind a local anesthetic increases over time, leaving ever fewer unbound Na channels available to change their molecular conformation and conduct Na ions when the surrounding membrane depolarizes. Eventually, a sufficient fraction of Na channels over a sufficient length of nerve will be bound by local anesthetics ...