Peripheral Nerve Blocks Flashcards
hypoechoic background with hyperechoic lines. Compressible
Fat
Bright hyperechoic lines
Fascia
hypoechoic background with hyperechoic lines. Non-Compressible. Surrounded by hyperechoic lines
Muscle
Very bright hyperechoic line with anechoic region beneath.
Bone
Hyperechoic and hypoechoic. Honeycomb appearance. Above clavicle more hypoechoic and below clavicle more hyperechoic
Nerves
Postganlionic sympathetic and afferent sensory. Only unmyelinated nerve fiber. Autonomic, pain and sensation
C Fibers
Preganglionic sympathetic. Autonomic
B Fibers
Afferent sensory nerve. Pain and sensation
A(delta)
Afferents to muscles and joints. Proprioception
A(Beta)
Efferents to muscle spindles. Muscle Tone
A(gamma)
Efferents to motor and joints. Motor
A(alpha)
Nerve block onset
B >C & A(d) > A(g) > A(b) > A(a)
Nerve block recovery
A(a) > A(b) > A(g) > C & A(d) > B
LAST (LA Systemic Toxicity ) - Drugs not to use
B-Blockers, Ca Channel Blockers, or LAs
Dont give Propofol
Also, reduce ept to < 1mcg/kg
T or F. Heparin 5000 SQ BID and Aspirin/NSAIDs may be administered at any time with no restriction on regional.
True
In general must wait anywhere from __-__ half-lives after administration of anticoagulant before regional can be safely performed.
3-5 half lives
Kidney and Liver dysfunction means one should wait longer before regional can be safely performed
Current intensity = measured in __. You should start at ___ and dial down. When you get to < ___ it is ok to inject LA
mA, 1.5mA, 0.7mA
_____ is used foe sensory vs. motor differentiation and is especially useful in neuropathic patients
Pulse duration = duration of current.