Smaller nerves are easier to anesthetize than larger nerves.

Smaller nerves are easier to anesthetize than larger nerves.

• A. True
• B. False
• C. Not determinable
• D. Depends on nerve type

Answer: (A)

Local anesthetics block conduction by inhibiting voltage-gated sodium channels, and their effect is influenced by fiber size and myelination. Smaller-diameter fibers, especially when they are myelinated or unmyelinated autonomic and pain fibers, reach conduction block at lower concentrations and with shorter exposure than larger, thicker fibers. This makes them easy to anesthetize early in a block. Clinically, you typically see autonomic dysfunction and loss of pain sensation before motor function is affected as the blockade progresses. So, the statement that smaller nerves are easier to anesthetize than larger nerves is consistent with how local anesthetics preferentially affect small-diameter fibers first.

Local anesthetics block conduction by inhibiting voltage-gated sodium channels, and their effect is influenced by fiber size and myelination. Smaller-diameter fibers, especially when they are myelinated or unmyelinated autonomic and pain fibers, reach conduction block at lower concentrations and with shorter exposure than larger, thicker fibers. This makes them easy to anesthetize early in a block. Clinically, you typically see autonomic dysfunction and loss of pain sensation before motor function is affected as the blockade progresses. So, the statement that smaller nerves are easier to anesthetize than larger nerves is consistent with how local anesthetics preferentially affect small-diameter fibers first.