Lower Extremity Blocks Flashcards
name innervations of these areas (clockwise rotation)
genitofemoral
ilioinguinal
obturator
anterior femoral cutaneous
saphenous
lateral femoral cutaneous
name the blocks of the LE
femoral plexus block
fascia iliaca block
single nerve blocks
femoral nerve
obturator nerve
later femoral cutaneous nerve
Which block is also known as the 3 in 1 block?
fascia iliaca block
what nerves are blocked in the fascia iliaca block?
femoral nerve
lateral femoral cutaneous nerve
obturator (unreliable coverage)
which block is a volume dependent compartment block?
fascia iliaca block
what volume is used for fascia iliaca block?
40-60ml of LA
fascia iliaca block indications?
anterior thigh
knee surgery
hip procedures
femur fx
name these structures
top to bottom:
lateral femoral cutaneous nerve
inguinal ligament
femoral nerve
why is the fascia iliaca block so safe?
no major nerve or blood vessels near site of injection
complications fo fascia iliaca block?
block failure
hematoma
toxicity
nerve damage
position for fascia iliaca block?
supine
can fascia iliaca block be perfomed reliably under non US techniques? what are these techniques?
no
these unreliable techniques are the pop pop technique and NS technique
what two appraoches wit US probe can be used for fascia iliaca block?
transverse and parasagital
describe transverse approach to fascia iliaca block
probe placed transverse over femoral artery and slid lateral
injection is placed around lateral 1/3 of lien betwen ASIS and pubic tubercle
where will you see lateral femoral cutaneous nerve when doing transverse approach to the fascia iliaca block? Can it be blocked individually?
between sartorius and tensor fascia lata muscle
yes
name this view and structures
medial view with tranverse probe for fascia iliaca block
(clockwise)
femoral artery
femoral nerve
ilacus muscle
fasci iliaca
name this view and structures
Middle view (between medial and lateral) with transverse prove for fascia iliaca block
ilacus muscle and sartorius muscle
name this view and structures
lateral view with tranverse probe for fascia iliaca block
tensor fascia lata muscle, lateral femoral cutaneous nerve, and sartorius muscle
describe parasagittal approach to fascia iliaca block
locate ASIS and move prove medially until target appears. “bow tie” appearance
needle approach from inferior edge of probe
goal: injection of LA below fascia iliaca between sartorius and internal obliques
name this block and technique
parasagittal approach for fascia iliaca compartment block
name this block with the technqiue and each structure
fascia iliaca block with US parasagittal approach
abdominal muscle
iliacus
fascia iliaca
sartorius
which nerve block is very easy to learn because of consitent anatomy, superficial location, and it is easy to find?
femoral nerve block
two main divisions of the femoral nerve?
anterior and post divisions
divisions of the anterior division of the femoral nerve and their function?
cutaneous branches:
intermediate and medial femoral cutaneous nerves, cutaneous innervation to anterior thigh
muscular branches
pectineus and sartorius
divisions of post division of femoral nerve and their function?
motor innervation to quadriceps
rectus femoris
vastus lateralis
vastus medialis
vastus intermedius
articular branches: sensory innervation to knee joint
what makes up the femoral triangle
sartorius m. adductor longus m. ilioinguinal ligament?
indications for femoral nerve block?
ant thigh surgery
knee surgery, ACL, PCL, patellar tendon
total/partial joint: has fallen out of favor because of quad weakness and falls. Adductor canal used instead
what is in the femoral triangle?
VAN
vein artery nerve from medial to lateral
or lateral to medial NAVEL (nerve, artery, vein, lymph nodes, empty space)
is the femoral nerve block easy via NS technique
yep
positioning for femoral nerve block?
patient is supine, obese may need panniculus retraction
femoral nerve block technique under NS
femoral artery palpated in femoral crease
needle inserted lateral to artery and perpendicular to skin, slightly cephalic
looking for quad twitch or patellar snap
what is this?
femoral nerve block under NS
what is this?
femoral nerve block under NS
anatomically where does femoral nerve run?
in groove created by iliacus and psoas muscles
what to do if you get no response for femoral nerve block when using NS?
you are either too meidal or too lateral, try again
what to do if you hit bone during femoral nerve block when using NS?
you are too deep, withdraw to level of the skin and repeat the procedure
what to do if you get local twitch for femoral nerve block when using NS?
direct stim of the iliopsoas or pectineus m., needle is too deep or too cranial, re try the procedure
what to do if you get sartorius muscle twitch with femoral nerve block when using NS?
needle tip is slighty anterior and medial, redirect needle laterally and deeper,
what to do if you get vascular puncture with femoral nerve block when using NS?
needle is too medial, withdraw and insert 1cm laterally
how to do US guided femoral nerve block?
place probe in femoral crease, insert needle lateral to medial in the in plane fashion
how might femoral nerve appear under ultrasound?
oval or triangular (actually a ton of different nerves all together), usually hyperechoic
name this block
femoral nerve block under ultrasound
where must LA be injected for femoral block?
below facia iliaca
name this block, and is this the first or second needle position?
femoral block, first needle position, inject 1/2 LA here
name this block and the needle position. (ist or second)
fem block 2nd needle position
name the structures
femoral block
femoral vein
femoral artery
femoral nerve
iliacus muscle
indications for lateral femoral cutaneous nerve block?
lateral thigh
hip procedures
trourniquet pain
are non-US techniqes reliable for lat fem cutaneous block?
no, but they are still used a lot
name this block
lateral femoral cutaneous block
what position for lateral femoral cutaneous block?
can be supine or lateral
if you use NS with lat fem cutaneous block what is the goal?
paresthesia to lateral thigh
where does LFCN run?
between tensor fascia lata muscle and sartorius m.
what voluem for LFCN block?
5-10cc LA
what do you want the injected LA to do in LFCN block?
dissect facial layer between muscles
name this block
obturator nerve block
what does obturator nerve innervate?
motor: adductor magnus, longus, brevis, and gracilis
sensory: medial thigh, knee, medial knee joint
indications for obturator nerve block?
knee surgery
amputations
touriquet pain
TURBT surgery (avoid knee jerk from obturator nerve stimulation when ablating tumors)
What are we looking at?
adductor longus muscle
adductor brevis muscle
adductor magnus muscle
pectineus
ant and post branches of obturator nerve
where is ant branch of obturator nerve located?
between adductor longus, brevis, and pectineus muscles
where is post branch of obturator nerve located?
between adductor brevis and magnus
function of ant branch of obturator nerve?
motor to adductors
sensory to medial thigh/knee
fucntion of post branch of obturator nerve?
primarily motor to abductors
sensory: articular branches to medial knee joint
position for obturator nerve block?
pt supine with leg abducted and slightly ext rotated
technique for US obturator nerve block?
probe 2-3cm distal to femoral crease
be careful of femoral vessels
5-10cc LA in each location, facial plane between longus and brevis, and facial plane between brevis and magnus
what with NS produce with obturator block?
adduction for both branches
name everything
femoral vein
femoral artery
adductor longus m.
ant branch of obturator nerve
adductor brevis m.
post branch obturator nerve
adductor magnus m.
pectineus m
femur
how was adductor canal block originally described?
alternate approach to saphenous
what does adductor canal block block?
sensory to the knee
motor sparing, vastus medialis occasionally blocked though
adductor canal block indications?
knee surgery
medial leg/ankle procedures
why do surgeons love adductor canal blocks?
pt can still get up and walk but get the benefit of the block
what block is the adductor canal block used with and for what procedures?
used with popliteal approach to sciatic nerve
used for medial foot and ankle procedures
name the nerve
saphenous nerve
pt position for adductor canal block?
pt supine with leg abducted and slightly ext rotated
us technique for adductor canal block?
probe is transverse, mid thigh
needle approach ant to post
want to have SFA directly under the middle of the sartorius m.
volume for adductor canal block?
15-20ml
name this block
adductor canal
what needs to happen with injection and where should it be for adductor canal block?
needs to displace sartorius m upward.
should be on both sides of superficial femoral artery
continuous catheter can be placed above SFA but absolutley needs to be below sartorius m.
is the saphenous nerve always visible during adductor canal block?
no :(
name the block and structures
adductor canal block
sartorius m.
SFA
saphenous nerve
name the structures
sartorius m.
femoral artery
adductors
vastus medialis
saphenous n.
largest nerve in the body?
sciatic nerve
sciatic nerve function?
motor: hamstrings, muscles of lower leg and foot
sensory: post thigh, lower leg and foot (except saphenous)
what nerve does the majority of innervation below the knee?
saphenous n.
what nerve innervates these areas?
sciatic nerve
what determines extent of sciatic nerve blockade?
all about where you place the needle, hamstring motor branches early, tibial and peroneal may emerge as entierly seperate nerves
(the higher you go the more likely you are to get hamstrings)
name the missing nerves
peroneal division of sciatic nerve
tibial division of sciatic nerve
common peroneal nerve
tibial nerve
Indications for sciatic nerve block?
knee surgery
adjuct to femoral or AC
surgery of post leg
hamstring reattachment
surgery of lower leg or foot
set up condisderations for sciatic nerve block?
may need crvilinear prove
long block needle (100-150mm) may be needed
goal with NS technique for sciatic nerve block?
twtich of calf, foot, or toes
hamstring inervation leaves sheath early so it is not a reliable predictor
name the six approaches for sciatic nerve block
anterior
transgluetal
subgluteal
mid femur
popliteal
tibial nerve
describe technqiue for NS guided anterior approach to sciatic nerve block?
line b/t ASIS and pubic tubercle
femoral pulse identified
4-5cm perpendicular from line
advance needle until twitch of calf, foot, or toes
might contact bone (lesser trochanter)
withdraw needle 1-3cm, internally rotate leg, readvance needle just past the bone
What is this showing?
anterior approach to sciatic nerve block
what is this?
anterior approach to sciatic nerve block
pearls for ant approach to sciatic nerve block?
elevate heel off bed to help identify twitches
sciatic nerve is prone to injury, avoid vasoconstrictors and he only uses ropivicaine
hit sciatic nerve first and then femoral
what is this?
anterior approach to sciatic nerve block
US technique for ant. sciatic nerve block?
probe transverse
curvilinear probe
needle in plane
use long needle 150mm
needle can go medial to lateral or lateral to medial
be aware of FA/FV
sliding or tilting probe prox/distal may help visualize sciatic nerve
needle can be hard to drive this deep
volume for ant approach to sciatic nerve block?
15-20ml
indications for ant approach to sciatic nerve block?
any sciatic nerve indication
pt unable to turn lateral or prone
what is this?
ant approach to sciatic nerve block
name this
transgluteal approach to sciatic nerve block
NS technique for transglueteal sciatic nerve block?
lateral oblique position
ID greater trochanter, and PSIP
needle insertion 4cm distal to midpoint
block leg flexed over bottom with foot free to show twitch
troubleshooting transglueteal sciatic nerve block:
local twitch of glueteus
needle hits bone but no local twitch of gluteus
needle hits bone, sciatic twitch not elicited
needle placed deep (8-10cm) twitches not elicited; bone is contacted
hamstring twitch
twitches of foot/toes
needle to superficial, keep advancing needle
needle is inserted too close to the attachment of the fluteus muscle to the iliac bone: stop and check landmarks
needle missed teh plane of the sicatic nerve and is stoped by the hip joint or ischial bone: with draw needle and redirect it more medially or laterally
needle passed through sciatic notch, withdraw th needle and redirect slightly superiorly
stimulation of main trunk of sciatic nerve: accept and inject
stimulation of sciatic nerve: accept and inject
what is this?
US trans glueteal approach to sciatic nerve block
describe trans-gluteal approach to sciatic nerve block
lateral position, hips flexed
probe between greater trochanter and ischium tuberosity
needle inserted from lateral aspect of the probe
where is sciatic nerve when looking at US using transglueteal approach?
predicitably between femur, ischial tuberosity, and below gluteus maximus
what volume for transgluteal sciatic nerve block?
15-20ml, ensure good LA coverage
name the block and structures
trans-gluteal sciatic nerve block
gluteus maximus m.
ischial tuberosity
sciatic nerve
femur
tell me about the sub-gluteal US approach to sciatic nerve?
very similar to tranglueteal, you just place probe a few cm distal.
pros: less tissue, may allow for linear probe, less variability, only need to search lateral and medially to find the nerve
what is this?
sub-gluteal US approach to sciatic nerve block
subq tissue
GMM
need help with what else we are looking at here…
indications for popliteal approach to sciatic nerve with NS
foot or ankle surgery, analgesia adjunct for knee surgery
what position for popliteal sciatic nerve block?
lateral or prone
volume for popliteal sciatic block? what LA?
30-40, ropivicane with no epi
popliteal appraoch to sciatic nerve is commonly paired with what blocks?
femoral or addutor canal
describe NS technique for popliteal block
find crease of popliteal fossa
find lateral tendon of biceps femoris
find medial tendon of semitendinosus m.
measure 7cm from crease, mark midpoint between both lines
insert needle at midpoint between both tendons, typically about 3-5cm deep
what are we looking at?
popliteal NS block
what are we looking for when using NS with politeal block?
TIPPED
Tibial inversion, plantar flexion
peroneal eversion, dorsiflexion
position for popliteal block?
supine, lateral, or prone
what volume for popliteal block?
20-30cc
describe USG popliteal block
probe is tranverse
start at popliteal crease
ID artery, vein, tibial nerve
move proximally
watch tibial and peroneal come together
place injection when the 2 have converged
what are we looking at?
popliteal block
common peroneal nerve
tibial nerve
popliteal artery
what are we looking at?
popliteal block
sartorius m.
semimembranosus muscle
popliteal artery
sciatic nerve
biceps femoris m.
indication for tibial nerve block?
total knee
why do a tibial block?
avoid the foot drop you get if peroneal n, is also blocked
volume for tibial block?
5-8ml
needle insertion for tibial block?
from medial site
be careful to only place LA near tibial and not peroneal nerve
5 nerves to block in ankle blocks?
superficial:
superficial peroneal
sural
saphenous
deep:
posterior tibial
deep peroneal
what needle to use with ankle blocks?
25g 1.5” needle
how do you do a deep peroneal block?
ID extensor hallucis longus
insert needle just lateral advancing until contact with bone, withdraw 2mm and inject
volume for deep peroneal block?
2-4cc
how to do posterior tibial block?
id medial malleolus,
insert post and contact bone, withdraw 2mm an dinject 2-4ml of LA
what volume with post tibial block?
2-4cc
name the nerves that innervate each area
boom
how do you block superficial ankle nerves?
create subQ wheel around the entire ankle
saphenous: wheel from tbial ridge medially to achelies
superficial peroneal: wheel from tibial ridge laterally to lateral malleoulus
sural: wheel from lateral malleolus to achilles
deep peroneal nerve runs with what? and turns into what?
runs with ant tibial artery, turns into dorsalis pedis distally
what does post. tibial nerve run with?
immediately post to post tibial artery
what volume to block deep peroneal and posts tibial arteries?
2-4ml
what are we looking at?
what are we looking at?
