LE blocks Flashcards

1
Q

lumbar plexus originates from anterior rami of

A

L1-L4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

sacral plexus originates from posterior rami of

A

L4-S4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

draw the lumbar plexus

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

draw the sacral plexus

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

six branches of lumbar plexus in order

A

iliohypogastric
ilioinguinal
genitofemoral
lateral femoral cutaneous
obturator
femoral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

lateral femoral cutaneous
arises from
forms
courses

A

arises from L2-3 posterior divisions
forms the midpoint of the psoas muscle
courses laterally along the anterior iliac spine, and then passes under the lateral border of the inguinal ligament

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

the femoral nerve
arises from
forms
courses

A

arises from posterior divisions of L2-4
forms near the middle and lower 1/3 of psoas muscle
courses distally through groove created by psoas major and iliacus muscles under inguinal ligament lateral to the femoral artery and anterior to the ilipsoas muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

the femoral nerve divides into

A

anterior and posterior branches
the posterior branch gives rise to one terminal branch (saphenous nerve)
the saphenous nerve courses through adductor canal and becomes superficial at the knee

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

the sacral plexus forms anterior to

A

the psoas major

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

five major branches of sacral plexus include

A

superior gluteal
inferior gluteal
posterior cutaneous
pudendal
sciatic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

the sciatic nerve arises from
courses through

A

arises from L4-S3 (comprised of tibial and common fibular trunks)
courses through sacrosciatic foramen (underneath piriformis muscle) and descends between major trochanter and ischial tuberosity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

the sciatic nerve divides into 2 branches (which branches and where does it divide)

A

divides into tibial nerve and common peroneal nerve (fibular nerve) at proximal popliteal fossa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

the tibial nerve
arises from
course through

A

sacral nerve (anterior branch of L4-S3)
courses medially through popliteal fossa distally and between medial and lateral heads of gastrocnemius muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

the tibial nerve gives rise to what

A

1 terminal branch (posterior tibial nerve)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

the common peroneal nerve
arises from
courses through

A

sacral nerve (posterior branches of L4-S3)
courses laterally over head of the fibula before dividing into deep and superficial peroneal nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

the common peroneal nerve gives rise to what branches

A

3 terminal branches:
deep peroneal nerve
superficial peroneal nerve
sural nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what are the 5 terminal nerves at the ankle

A

saphenous (only one from femoral)
superficial peroneal
deep peroneal
sural
posterior tibial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

innervation of A, B, C, D in this image

A

A: LFCN
B: obturator
C: saphenous
D: superficial peroneal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

dermatome L2
sensory region

A

medial upper thigh

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

dermatome L3
sensory region

A

medial lower thigh

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

dermatome L4
sensory region

A

lateral thigh and anterior knee

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

dermatome L5
sensory region

A

lateral lower leg and top of foot

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

dermatome S1
sensory region

A

posterior leg (more lateral)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

dermatome S2
sensory region

A

posterior leg (more medial)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

peripheral nerves of LE that are only sensory

A

LFCN
saphenous
sural

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

peripheral nerves of LE that are combined motor and sensory

A

femoral
obturator
posterior tibial
deep peroneal
superficial peroneal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

sensory region of femoral nerve

A

anterior branch -> anterior thigh
posterior branch-> saphenous nerve->medial aspect of lower leg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

sensory region of obturator nerve

A

articular branches of hip joint
medial thigh

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

sensory region of LFCN

A

lateral thigh to knee

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

sensory region of pudendal nerve

A

perineum
anal canal and external sphincter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

sensory region of posterior femoral cutaneous nerve

A

posterior hip to mid calf

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

sensory region of posterior tibial nerve

A

plantar surface of foot

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

sensory region of superficial peroneal nerve

A

dorsal surface of foot

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

sensory region of deep peroneal nerve

A

web space between big toe and second toe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

sensory region of sural nerve

A

lateral aspect of foot

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

motor function of femoral nerve

A

hip–> flexion and lateral rotation
knee–>extension and flexion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

motor function of obturator nerve

A

motor adduction, flexion, extension

38
Q

motor function of LFCN

A

none

39
Q

motor function of pudendal nerve

A

sphincter tone

40
Q

motor function of sciatic nerve

A

hip: extension
knee: flexion

41
Q

motor function of tibial nerve

A

toe: abduction, adduction, extension, flexion
ankle: plantar flexion

42
Q

motor function of superficial peroneal nerve

A

ankle->eversion

43
Q

motor function of deep peroneal nerve

A

ankle–>dorsiflexion and inversion

44
Q

review osteotomes

A
45
Q

what nerves does the PENG block target

A

femoral nerve
accessory obturator nerve
obturator nerve

46
Q

key anatomic landmarks for the PENG (pericapsular nerve group) block include

A

femoral vein, artery, nerve (m to l)
iliopsoas muscle and tendon
anterior inferior iliac spine (AIIS)
iliopubic iminence (IPE)

47
Q

the location of the PENG block decreases risk of quads weakness because

A

of the distance from the femoral nerve. femoral nerve is spared because injection happens deep to iliopsoas muscle

48
Q

what is the PENG block indicated for
what nerves it targets

A

hip fractures or arthroplasty
targets nerves from lumbar plexus that supply sensory innervation to hip capsule

49
Q

when combined with a LFCB, the PENG block provides an alternative for

A

femoral and fascia iliaca block

50
Q

USG PENG block technique

A
  1. place patient in supine position with slight external rotation of extremity
  2. place low frequency curvilinear array transducer (2-5mHz) in transverse orientation on the proximal thigh distal to the inguinal ligament.
  3. the hyper echoic femur provides contrast. slide transducer cephalad towards level of rounded acetabulum to level of anterior inferior iliac spine and pubis ramus are visible.
  4. at this level, visualize femoral artery, vein, and nerve superior to iliopsoas muscle
  5. the iliopubic eminence (IPE) formed by junction of ilium and pubis creates a floor. note hyper echoic psoas tendon is immediately superior to IPE
  6. insert 20g tuohy needle. larger diameter facilitates injection in tight space between psoas and IPE
51
Q

complications of PENG

A
  1. injecting straight into psoas may facilitate muscle weakness
  2. inserting needle above inguinal ligament and advancing too medially increases risk of injecting into pelvic cavity and puncturing vital structures (ex ureter)
52
Q

fascia iliaca block targets which 3 nerves

A

femoral, obturator, LFCN

53
Q

indications for fascia iliaca block

A

surgical procedures involving femur, quadriceps, knee
acute pain management for hip fx
-when compared to lumbar plexus block, provides faster and more consistent block of LFCN and femoral n

54
Q

USG fascia iliaca block

A

(doesn’t require nerve stimulation)
1. place high frequency linear array transducer in saggital orientation at anterior superior iliac spine (ASIS) and slide to brim of the pelvis
2. rotate caudal end of transducer slightly lateral to bring sartorious and internal oblique muscles (which form bow tie) into view
3. insert 22g 9cm B bevel needle using an in plane approach 1cm cephalad to the inguinal ligament in a cranial dorsal direction until it pierces the inguinal ligament
4. using hydro dissection, inject 1-2mL of NS to separate fascial from iliacus muscle.
5. following negative aspiration, inject 1-2mL to separate fascia iliaca from iliopsoas muscle.
6. inject 40mL LA in 5mL increments

55
Q

landmark fascia iliaca block

A
  1. place patient in supone position
  2. at the level of inguinal ligament, draw a line from anterior superior iliac spine (ASIS) to the pubic tubercle and divide it into thirds
  3. insert the needle 1cm caudal from the line separating the lateral and middle third
  4. insert 22g 5cm B bevel needle perpendicular to the skin
  5. you should feel a loss of resistance as the needle passes through the fascia lata. advance until you feel a second loss of resistance through fascia iliaca
  6. following negative aspiration, inject 40mL in 5mL increments
  7. apply manual pressure distal to insertion site to prevent caudal spread of LA
56
Q

complications of fascia iliaca block

A

LA injected above fascia iliaca results in failed or incomplete block
d/t large volume of LA injected, you may see quad weakness and the possibility of LAST

57
Q

borders of the femoral triangle for the femoral nerve block

A

corners look like a SAIL so borders are
sartorious
adductor longus
inguinal ligament

58
Q

indications for femoral nerve block

A

surgical anesthesia and analgesia for procedures involving hip, femur, quads, knee
offers reliable acute pain management for hip fractures

59
Q

USG FNB

A
  1. place patient supine with slight external extremity rotation
  2. place high frequency linear array transducer (10-12 MHz) in transverse orientation at inguinal crease
  3. ID major anatomical landmarks. FN appears hyper echoic below fascia lata and iliaca
  4. prep, drape, insert a 22g 5cm B bevel needle using in plane approach through fascia lata and iliaca just lateral to the femoral artery. direct needle inferior to aspect of nerve to elicit a response.
  5. following negative aspiration, inject 20-30mL of LA in 5mL increments
60
Q

landmark FNB

A
  1. place patient in supine with slight external rotation
  2. palpate femoral artery from ASIS to pubic tubercle
  3. place x 1cm lateral and 1cm inferior to inguinal ligament
  4. prep, drape, skin wheal, insert 22g 5cm B bevel needle in a slightly cephalad direction.
  5. set nerve stimulator to 1mA and go until you see patellar snap. 2 pops is fascia lata and iliaca. advance the needle and ensure patellar snap at .3mA to ensure optimal location
  6. inject 20mL in 5mL increments.
61
Q

what happens if you get inner thigh twitching during FNB

A

you are activating sartorious muscle. withdraw needle and advance slightly laterally.

62
Q

complications of FNB

A

because of block of femoral artery, this FNB adds to falls post LE surgery
uncommon but vascular puncture and nerve injury

63
Q

adductor canal block femoral triangle boundaries include

A

inguinal ligament (base)
medial aspect of sartorius (medial aspect)
medial aspect of adductor longus lateral side of triangle)
(adductor canal originates at apex of femoral triangle)

64
Q

indications for ACB

A

anterior cruciate ligament repair
medial collateral ligament repair
patella fracture
vein stripping and harvesting
supplement to sciatic block or foot/ankle surgery

65
Q

USG ACB

A
  1. place patient supine with slight external rotation of extremity
  2. position high frequency linear array transducer (10-12mHz) in transverse orientation at mid to distal 2/3 of thigh
  3. ID femoral artery inferior to sartorius and transducer. saphenous nerve is hyper echoic and anterolateral to artery
  4. prep and drape, do skin wheal, use 22g 9cm B bevel needle using an in plane approach to the fascial plane between VM and sartorius.
  5. following negative aspiration, inject 15-20mL in 5mL increments.
66
Q

complications of ACB

A

quads weakness is more likely with proximal injections and ones that exceed 20mL
vascular puncture, nerve injury, and myotoxicity if injected inside muscle.

67
Q

key anatomic land marks of popliteal nerve block includes

A

popliteal artery and vein
biceps femoris, semitendinosus, and semimembranosus muscles
bifurcation of sciatic nerves into common tibial and peroneal nerves.

68
Q

indications for popliteal nerve block

A

provides pain control for below the knee surgical procedures such as ankle, achilles tendon, foot surgeries. also helps manage acute pain
when combined with saphenous nerve block, provides complete coverage of LE below knee

69
Q

USG popliteal nerve block

A
  1. on US, TN appears hyper echoic. dorsal and lateral to artery and vein in popliteal fossa.
  2. prep, drape, insert 22g 9cm B bevel needle using in plane approach until tip is at bifurcation of two branches. advance needle further to medial border of TN. following negative aspiration, inject 10mL circumferentially around TN. slowly withdraw needle to lateral edge of CPN. following negative aspiration, inject 10mL around CPN.
70
Q

landmark popliteal nerve block

A
  1. with the patient in prone position and with slight flexion, draw a line from biceps femoris medially to semitendinosis at popliteal crease.
  2. at midpoint, extend a perpendicular line approx 10cm cephalad. needle insertion point is 1cm lateral to this line
  3. prep, drape, skin wheal at insertion site. 22g 9cm B bevel needle attached to nerve stimulator through wheal pointing slightly cephalad. set nerve stimulation at 2 Hz and 1mA and advance until either plantar flexion (TN) or dorsal flexion (CPN) motor response is initiated. do this until you get to .3 mA
  4. inject 20mL in 5mL increments.
71
Q

TIPPED pneumonic for tibial and peroneal

A

tibial inversion plantar flexion
peroneal eversion dorsiflexion

72
Q

complications of popliteal nerve block

A

nerve injury and inadvertent vascular puncture
foot drop and numbness of sole may lead to patient falls

73
Q

sensory innervation of stapnehous nerve on the foot

A

medial aspect of ankle and foot

74
Q

sensory innervation of the sural nerve on the foot

A

posterior portion of heel
lateral sole of foot
achilles tendon above ankle

75
Q

sensory innervation of superficial peroneal nerve on foot

A

dorsum of foot

76
Q

sensory and motor innervation of deep peroneal nerve on foot

A

sensory: lateral side of great toe (hallux). medial side of second digit
motor: eversion and dorsiflexion

77
Q

sensory and motor innervation of posterior tibial nerve on foot

A

sensory: sole of foot
motor: inversion and plantar flexion

78
Q

the one nerve in the foot that does not travel near a vascular structure

A

the superficial peroneal

79
Q

posterior tibial USG block

A
  1. place transducer in transverse orientation just above medial malleolus along medial aspect of the leg
  2. insert 22g B bevel block needle in plane (posterior to anterior) and deep to nerve vessels
  3. after negative aspiration, inject 3-5mL of LA
80
Q

posterior tibial land mark block

A
  1. draw a line connecting superior portion of medial malleolus and achilles tendon.
  2. prep, drape, palpate posterior tibial artery. if its palpable, insert needle perpendicular to the skin just posterior to the tibial artery
  3. if the patient c/o parasthesia, inject 5mL LA and slowly withdraw needle while injecting 3 more LA.
  4. if theres no paresthesia, advance the needle until it contacts medial malleolus and then withdraw 2-3mm. after negative aspiration, inject 5-8mL LA as you slowly withdraw the needle.
81
Q

USG sural nerve block

A
  1. position patient in supine position
  2. apply tourniquet around proximal tibia to dilate lesser saphenous vein
  3. prep, drape, place transducer in transverse orientation 1cm cephalad to lateral malleolus. you’ll image the LSV in cross section
  4. at this level, may be challenging to ID sural nerve. insert 22g B bevel needle in plane (posterior to anterior) just inferior to LSV
  5. after negative aspiration, inject 3-5mL LA
82
Q

landmark sural nerve block

A
  1. draw horizontal line from superior aspect of lateral malleolus to achilles tendon.
  2. prep, drape, insert needle in plane between achilles tendon and lateral malleolus
  3. after negative aspiration, inject 5mL LA as you slowly withdraw the needle.
  4. needle must reach superior border of lateral malleolus to anesthetize sural nerve.
83
Q

USG deep peroneal nerve block

A
  1. position patient supine
  2. prep and drape and place transducer in traverse orientation 1-2cm above medial malleolus at level of extensor retinaculum.
  3. visualize deep peroneal artery and veins in cross section and use these as a reference to ID hyper echoic nerve which you’ll see lateral or anterior to the artery
  4. insert 22g B bevel needle in plane (lateral to medial) to the inferior border of the nerve
  5. after negative aspiration inject up to 3-5mL LA elevating nerve off of the bone
84
Q

landmark deep peroneal nerve block

A

can block deep peroneal, superficial peroneal, and saphenous without removing the needle
1. with patient in supine position, draw a line from the medial malleolus to the superior border of the lateral malleolus across anterior aspect of ankle
2. prep, drape, ask patient to dorsiflex foot, bringing tendons of anterior tibial and long muscles of the great toe into view
3. insert needle perpendicularly into skin at midpoint between two tendons through the fascia.
4. advance the needle until you elicit paresthesia. confirm negative aspiration and slowly inject 5mL LA
5. if you dont elicit parasthesia, advance needle until you hit tibia then slightly withdraw it
6. after negative aspiration inject 5mL LA
7. inject additional 3mL as you slowly withdraw from fascia

85
Q

superficial peroneal USGRA

A
  1. position patient in supine position
  2. prep, drape, place transducer in transverse orientation approx 5cm proximal to lateral malleolus
  3. superficial peroneal nerve appears as small hyper echoic structure in SQ tissue in groove created by extensor digitorum and peroneus brevis longus muscle over fibula
  4. insert 22g B bevel block needle in plane (lateral to medial) towards inferior aspect of the nerve
  5. after negative aspiration, inject 3-5mL observing for circumferential spread
86
Q

landmark superficial peroneal nerve

A

after blocking deep peroneal nerve and without removing needle from skin, redirect needle tip towards inferior border of lateral malleolus in SQ tissue and block superficial peroneal nerve
as you withdraw needle towards midline, inject 5mL LA into SQ tissue creating wheal under skin

87
Q

saphenous USGRA

A
  1. position patient supine with slight external rotation of extremity
  2. prep, drape, apply tourniquet on proximal calf to better appreciate greater saphenous vein.
  3. place transducer in transverse orientation 5-10cm proximal to medial malleolus
  4. using GSV as landmark, ID stapnehous nerve medially as small hyper echoic structure
  5. insert 22g B bevel block needle in plane (lateral to medial) inferiorly to nerve and medial to GSV
  6. following negative aspiration, inject 3-5mL LA while observing for circumferential spread
88
Q

landmark saphenous

A

after blocking deep peroneal and superficial peroneal, return to midpoint without removing needle and redirect to inferior border of medial malleolus.
2. at this level, find saphenous nerve in SQ tissue adjacent to saphenous vein
3. after negative aspiration, inject 5mL LA beginning at medial malleolus
4. as you withdraw needle toward midpoint, inject an additional 3mL of LA

89
Q

complications of foot blocks

A

avoid large volumes of LA to not incite compression injury and ischemia
4/5 nerves course near vascular structures so big oopsies if you get into one of those and bleeding hematoma or LAST happens

90
Q

best way to determine adequacy of FNB? ask patient to

A

knee extension (because successful block mediates quadriceps weakness)

91
Q

which 3 ankle blocks can be done altogether without taking needle out

A

deep peroneal
superficial peroneal
saphenous