LE blockade (Part 3)

Question 1

is the largest nerve in the body, usually measuring about 2.5 cm wide

Answer 1

sciatic nerve

*about as wide as your thumb

Question 2

This nv & its branches supply innervation, both motor and sensory, to the posterior aspect of the entire LE to include the foot

Answer 2

sciatic nerve

Question 3

Anatomy: Sciatic nerve composted of nerve roots (2)

Answer 3

L4-5 and S1-3

Question 4

Sciatic n. provides sensory innervation to

Answer 4

posterior knee and entire leg, ankle, foot; except medial leg and ankle

Question 5

Sciatic n. divides into . . .

Answer 5

the tibial n and common peroneal n. in the popliteal fossa

Question 6

Indications for sciatic nv block (2)

Answer 6

Foot, ankle and achilles tendon surgery

Question 7

goal of sciatic nv block

Answer 7

Goal is to block it high enough; otherwise, you will obtain a partial block

Question 8

Block the sciatic nerve before it divides

Answer 8

Sciatic n. block at popliteal fossa

Question 9

Sciatic n. block at popliteal fossa positioning

Answer 9

Supine positioning with lateral approach or prone/lateral positioning and posterior approach

Question 10

Sciatic nerve block of the two terminal branches

Answer 10

Sciatic n. block at popliteal fossa

Question 11

Sciatic n. block at popliteal fossa Landmarks:

Answer 11

popliteal fossa crease, tendon of biceps femoris (laterally), tendon of semitendinosus and semimembranosus muscle (medially)

Question 12

needle insertion site of Sciatic n. block at popliteal fossa

Answer 12

Sciatic n. block at popliteal fossa

Question 13

“Popliteal Fossa Block” (Sciatic) steps

Answer 13

Identify the popliteal artery and vein at 3-4 cm depth
ID biceps femoris m(lateral) and SmM and StM (medial)
Tibial n is superficial and lateral to vein; hyperechoic, oval, honeycombed
CPN is slightly more superficial and lateral
Sliding the transducer cephalad, visualize the tibial and peroneal nerves combining to form the sciatic nerve at depth of 2-4 cm(5-10 cm from popliteal crease)
A spread of LA surrounding all sides of nerve

Question 14

what block is this

Answer 14

Popliteal Block

Question 15

how many nerves blocked in ankle block

Answer 15

5 nerves should be blocked

Question 16

Name the 5 nerves blocked in ankle block

Answer 16

3 superficial nerves
Saphenous (femoral)
Sural (tibial)
Superficial Peroneal (common peroneal)
2 deep nerves
Posterior Tibial Nerve (tibial)
Deep peroneal (common peroneal)

Question 17

Deep Peroneal block steps

Answer 17

Finger on the groove just lateral to the extensor hallucis longus
When the needle hits bone, withdraw 1-2 cm
Inject 5 ml LA
“Fan” the block
Palpate the tibial artery.
Using a 25 g needle, inject 5 – 8 ml of LA anterior to the arterial pulse.
If the artery can’t be palpated, inject just posterior to the medial malleolus, aspirating before and after injection.
Aspirate prior to this particular injection s
Needle groove behind the medial malleolus
Hit bone and then withdraw ~ 1 cm and fan injection of ~3 ml