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Flashcards in lumbar plexus Deck (40)
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1
Q

what do lower extremity nerve blocks provide

A

high quality of anesthesia and analgesia for the lower extremity

2
Q

lower limb regional anesthesia advantages

A
decreased 
PACU time
n/v
urinary retention 
increase post op analgesia
3
Q

lower limb regional anesthesia yields decreased

A

hospital stays and admissions

hospital and patient cost

4
Q

lumbar plexus provides innervation to the lower extremities nerve supply to lower extremity is composed of

A

lumbar plexus

sacral plexus

5
Q

the lumbar plexus lies with what muscle and branches into where

A

psoas

branches into the proximal thigh

6
Q

lumbar plexus primaries arrives

A

L1-L4

7
Q

lumbar plexus comes from 3 major nerves

A

lateral femoral cutaneous L2-L3

Obturator L2-L4

femoral L2-L4

8
Q

what nerve is frequently injured in pelvic surgery

A

obturator

9
Q

what is the largest branch of the lumbar plexus

A

femoral nerve

10
Q

the upper lumbar division supplies what two nerves

A

iliohypogastric nerves

ilioinguinal nerves

11
Q

what nerves combine with thoracic nerves innervates the trunk above the extremity

A

iliohypogastric nerves

ilioinguinal nerves

12
Q

sacral plexus is derived from

A

anterior rami of the L4 and L5 and S1-S4

13
Q

what is the largest nerve trunk in the body

A

Sciatic L4-S3

14
Q

what nerves arise from the sacral plexus

A

sciatic L4-S3

Posterior Cutaneous nerve S1-3

terminal branches-tibial and common peroneal

15
Q

what forms the sciatic and supplies both motor and sensory innervation to posterior aspect of the lower extremity and foot

A

sacral plexus

16
Q

what four major nerves supply all of the lower extremity

A

lateral femoral cutaneous nerve

femoral nerve

obturator nerve

sciatic nerve
-posterior cutaneous nerve of thigh (s1-s3)

17
Q

what are the indications for lumbar plexus block

A

when unilateral block is desirable

when spinal or epidural anesthetic is contraindicated for operations of hip thigh or upper leg

useful for surgical procedures involving areas innervated by femoral, lateral femoral cutaneous and obturators nerves (procedures on hip, knee and anterior thigh)

18
Q

Posterior Lumbar Plexus (Psoas Compartment) block: position:

A

Lateral (or Prone, lying over soft pillow)

Position: lateral (side to be blocked in the nondependent position/up)

19
Q

Posterior Lumbar Plexus (Psoas Compartment) block

Landmarks

A

4cm lateral to L4 Spinous processes

20
Q

Posterior Lumbar Plexus (Psoas Compartment) block

Anatomy

A

Reaching the posterior lumbar plexus requires a long needle
Depth of transverse process of lumbar vertebrae from the skin is approx 5 cm
Hence, this block has one of the highest complication rates of any peripheral nerve blocks….

21
Q

Posterior Lumbar Plexus (Psoas Compartment) block

complications:

A

Retroperitoneal hematoma

Intravascular LA injection (toxicity)

Intrathecal and/or epidural injection

Renal capsular puncture (hematoma)

22
Q

what two ways can be lumbar plexus block be done

A

prone or lateral positions

23
Q

what is the advantage of a prone position to block the lumbar plexus (psoas)

A

a more stable resting hand position, allowing more precise scanning and manipulation

24
Q

when preforming a lumbar block what care should be taken

A

frequent aspiration and injecting local anesthetic in small increments to detect epidural or spinal spread early

25
Q

the lumbar paravertebral space is a vascular and muscular space which leads to significant systemic absorption of local anesthetic- what is there a potential for

A

high plasma levels

26
Q

how do we identify the lumbar plexus

A

use of nerve stimulator

27
Q

for lumbar plexus block can continuous catheterization be used for prolonged analgesia

A

yes

28
Q

the lumbar block is ideal for what type of surgeries

A

hip surgeries and surgeries above the knee

29
Q

when the lumbar block is combined with the sciatic nerve block what does it provide

A

complete unilateral lower limb anesthesia suitable for lower extremity surgeries.

30
Q

the lumbar block does not supply complete anesthesia to the lower extremity- why is this?

A

does not supply complete anesthesia of lower extremity because it cann’t achieve blockade of the sacral roots that supply the sciatic nerve

31
Q

for lumbar block how where does the bevel of the needle face

A

bevel facing caudad and lateral

32
Q

technique for lumbar plexus block

A

palpate midline/spinous process

a line is drawn through the lumbar spinous processes

a line is drawn from iliac crest to iliac crest tuffiers line

palpate posterior superior iliac spine and draw another line cephalad parallel to the spinous process line

The site of needle entry is approximately 4 cm lateral to the spinous processes on the line drawn b/w the iliac crests (Tuffier’s line)

33
Q

lumbar plexus length and needle size

A

8-15 cm insulated 21 G needle inserted at the point of intersection b/w the transverse line and the intersection of the lateral and middle thirds of the 2 sagittal lines

34
Q

the lumbar plexus block needle is advanced in an terror direction in the posts compartment

A

The needle is advanced in an anterior direction until in the Psoas compartment (a femoral motor response is elicited (quadriceps) at 0.5 mA)

35
Q

after proper position how much local anesthetic is injected into the lumbar plexus

A

20-30 ml

greater than 20 may increase risk of bilateral spread

36
Q

how long for the local anesthetic to spread to the roots of the lumbar plexus

A

15-20min

37
Q

lumbar plexus depth
men
women

A

men 8.4cm

women 7.1cm

38
Q

If transverse process is contacted in lumbar block

A

the needle should be withdrawn slightly and walked off the transverse process in a caudal (toward tail) direction (never insert more than 2-3cm past the depth at which the transverse process was catheter- dont go too deep.

39
Q

the lumbar plexus block is a deep block that makes it difficult to appreciate the difference in the echogenicity of the anatomic structures especially in the

A

elderly and obese patients.

40
Q

which block has the highest complications

A

lumbar plexus block