Keyword
differential sensory block
differential blockade
Definition
- differences in the peak block height (highest or most cephalad level of anesthesia) according to each sensory modality
- due to relative sensitivity or susceptibility to the effects of local anesthetics
Mechanism
speed of neural blockade depends on
- size
- surface area
- degree of myelination of the nerve fibers exposed to the local anesthetic
해부학적으로는 S1과 L5 posterior root가 제일 커서 epidural anesthesia에서 제일 마취에 저항이 강하다.
Abstract
- B fibers : sympathetic fibers, small preganglionic , 1 to 3 μm, minimally myelinated
- C fibers: cold temperature sensation, 0.3 to 1 μm, unmyelinated
- A-delta fibers: pinprick sensation, 1 to 4μm, myelinated
- A-beta fibers: touch sensation, 5 to 12 μm, myelinated
- A-alpha: motor fibers, 12 to 20 μm, myelinated