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Flashcards in sciatic nerve Deck (41)
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1
Q

what block is very helpful for managing phantom limb pain after either below knee or above knee amputations

A

sciatic block continuous

2
Q

what med and dose is is administered after total knee to manage posterior knee pain

A

single shot sciatic block using 0.1% ropivicaine

3
Q

very tight as or heart failure what block is sufficient for lower limb procedures

A

combined femoral and sciatic block

4
Q

when is sciatic nerve block done alone

A

for ANALGESIA of the lower leg and provides pain relief from ankle fractures or tibial fractures before operative intervention

5
Q

outpatients sciatic blocks and satisfaction

A

Outpatients undergoing a complex knee surgery that have received combination blocks have decreased pain, hospital admissions, and increased satisfaction

6
Q

sciatic blocks indicated

A

Mostly indicated for procedures involving the hip, thigh, knee, lower leg & foot

7
Q

Sciatic nerve block in combination with Lumbar Plexus or Femoral block can provide

A

Sciatic nerve block in combination with Lumbar Plexus or Femoral block (3-in-1) can provide complete anesthesia and postoperative analgesia for lower extremity surgery

8
Q

Sciatic nerve is the continuation of the

A

upper division of the sacral plexus

9
Q

sciatic nerve originates from the lumbosacral trunk- composed nerve roots

A

Originates from the lumbosacral trunk and is composed of nerve roots L4-5 and S1-3

10
Q

the sciatic supples the muscles of..

A

It supplies the muscles of the posterior thigh, skin of the leg, and muscles of the lower leg and foot

11
Q

blockade of the sciatic nerve occurs where

A

Blockade of the sciatic nerve may occur anywhere along its course

12
Q

Position: sciatic nerve block

A

Lateral (side to be blocked in the nondependent position/up)

Bend knee of the affected leg and tilt the pelvis slightly forward (Sims position

13
Q

what is continuous sciatic block used for

A

continuous sciatic block is very helpful for managing phantom limb pain after either below knee or above knee amputations

14
Q

the keys to making sciatic block work

A

adequate positioning of the patient and a systematic redirection of the needle until paresthesia is obtained

15
Q

sciatic block posterior/classic approach

A

Identify the greater trochanter, posterior iliac spine & sacral hiatus
1st-draw a line from the posterior superior iliac spine (PSIS) to the greater trochanter
2nd-draw a line from the sacral hiatus to the greater trochanter
3rd-at the midpoint of line one draw a line that is perpendicular and intersects line two
Needle insertions is at the intersection of line 2 and 3

16
Q

sciatic block injection of LA

A

25ml

17
Q

sciatic block- needle length

A

Insert a long (10 cm) insulated needle at a perpendicular angle

18
Q

Sciatic block- what muscle does the needle advance through

what muscles respond to block?

A

Advance the needle through the gluteal muscles (a motor response of these muscles and leg may be elicited) until plantar or dorsiflexion is elicited (plantar flexion- distal ankle, foot or toes… or foot inversion)

19
Q

side effects of sciatic nerve blocks

A
Mild hypotension due to sympathetic fibers being blocked
Residual dysesthesias (abnormal sensation) usually improving 1-3 days
20
Q

major risk of popliteal nerve block

A

Major risk:

Vascular puncture

21
Q

what type of blocks are excellent for coverage for foot and ankle surgery (spares most of hamstring muscles, allowing amulation

A

popliteal nerve block

22
Q

for posterior popliteal approach - place probe

A

May use US … place probe just above the crease of fossa

23
Q

this block spares hamstring and allows ambulation

A

popliteal

24
Q

popliteal block positioning

A

Prone position and flex the leg (knee) to aid in identifying the margins of the popliteal fossa (prop the ankle on pillows/towels/blankets)

25
Q

where do you find the epicondyles of the femur

A

The base of both triangles forms a line between the medial and lateral epicondyles of the femur.

26
Q

how the fossa itself divided for popliteal approach

A

into equal medial and lateral triangles

27
Q

for popliteal posterior approach the needle

A

needle insertion at 5-6cm proximal to the skin crease and 1 cm lateral to the midline of the triangle

28
Q

popliteal needle
degree
gauge
direction

A

5-10cm insulated
22g
45-60degree
anterosuperior direction

29
Q

how much local is injected into popliteal block

A

30-40ml

30
Q

popliteal is advanced to what depth 1.5-2cmuntil

A

foot twitch

31
Q

Most medial branch of the femoral nerve

A

saphenous nerve at knee

32
Q

Saphenous Nerve – what does it innervate

A

Innervates skin over the medial leg & ankle joint

33
Q

saphenous nerve is commonly used in conjunction with with block

A

Commonly used in conjunction with sciatic (popliteal) block to provide anesthesia/analgesia below the knee

34
Q

how much local anesthetic is injected into the saphenous nerve

A

The saphenous nerve may be blocked by injecting 5-10 ml of local anesthetic in a subcutaneous ring from the medial aspect of the tibia to the border of the patellar tendon

35
Q

saphenous nerve- needle length and direction

A

Insert a short block needle 2 cm distal to the tibial tuberosity and directed medially (infiltrating 5-10 mL of LA) toward the posterior aspect of the leg

36
Q

indications for ankle block

A

diagnostic, therapeutic or surgical procedure on the foot

37
Q

ankle block can be good for

A

postoperative analgesia

38
Q

what is advantageous of the ankle blok

A

it is fast and low risk

39
Q

what two things do we avoid with ankle block

A

excessive la volume

avoid epi

40
Q

ankle block
Blockade of all the nerves serving the foot at the level of the proximal ankle joint
Requires 5 separate injections

A

Posterior tibial nerve- direct continuation of tibial
Deep peroneal nerve- runs off common peroneal
Superficial peroneal nerve- runs off common peroneal
Sural nerve- branch of tibial
Saphenous nerve (terminal branch of femoral)- not a part of sciatic system

41
Q

sural nerve injection amount

A

5ml