spinals & epidurals Flashcards
from superficial to deep, what are the ligaments
interspinous ligament, ligamentum flavus, posterior longitudinal ligament, anterior longitudinal ligament
piercing the ___ contributes to the loss of resistance when the needle enters the epidural space
ligamentum flavum
midline approach passes thru which 3 ligaments
surpaspinous, interspinous, ligamentum flavum
paramedian approach passes thru
ligamentum flavum
an epidural hematoma accumulates between the ___ and the ___
dura bone
epidural space is located between?
ligamentum flavum and dura mater
subdural space is located between?
dura mater and arachnoid mater
subarachnoid space is located between?
arachnoid mater and pia mater
how many cervical vertebra
7 (c1-c7)
how many thoracic vertebra?
12
how many lumbar vertebra
5
how many sacral vertebra
5
how many coccygeal vertebra
4
LA’s are bases or acids?
weak bases
esters have __ structure
c-o-c
amides have __ structure
N-h
agents with a ___ pka value will have a ___ onset
lower , faster. because a greater fraction of molecules will exist in the uncharged form, this will more easily diffuse across nerve membranes
the ___ form of an LA is most lipid soluble and is able to gain access to the axon
uncharged
mechanism of LA’s
block nerve conduction by impairing propagation of the action potential in axons
LA’s ___ the rate of rise of the action potential such that threshold potential is not reached
decrease
does the unionized form of the drug work while inside the cell?
no! it becomes ionized once inside
LA’s work ___cellularly
intra.
agents with a high degree of protein binding will have a ___duration
prolonged
pka determines __ of onset of neural blockade
speed