Anesthesia Blocks Lumbosacral

Front 1

Indications for Lumbosacral block?

Back 1

For procedures of the lower extremities
The lumbo-sacral and 3 in 1 blocks can provide adequate anesthesia over a variety of regions with the added benefit of post-op pain control.

Front 2

Local Anesthetic Drug Dosages for Lumbosacral blocks?

Back 2

Normal dosing volume is 20-40cc. Concentrations of local anesthetics may vary, keeping in mind higher concentrations will provide a denser block. Caution must be taken when calculating the dose not to exceed toxic dosages.
Lidocaine

Front 3

Lidocaine Drug Dosages for Lumbosacral blocks?

Back 3

For fast onset and short duration block
Usually 0.5-1.0% with a max dose of 5mg/kg (7mg/kg with 1:200,000 of epi)
Onset 10-20 mins
Duration 4-8 hours.

Front 4

Bupivacaine Dosages for Lumbosacral blocks?

Back 4

Used for longer duration and denser blocks
Usually 0.25-0.5% with a max dose of 3mg/kg
Onset 20-30mins
Duration 18hrs, therefore, epi is usually not indicated.

Front 5

Ropivacaine Dosages for Lumbosacral blocks?

Back 5

Use becoming more widespread in lieu of bupivicaine because higher clearance results in less toxic events
Usually 0.2-0.5% with max dose of 3mg/kg
Onset and duration similar to bupivicaine and epi not indicated.

Front 6

What spinal nerves form the lumbar plexus?

Back 6

L2-L4

Front 7

Where do the motor and sensory innervation of the lower extremities arises from?

Back 7

the nerve roots of the L2-S3 spinal segments.

Front 8

What spinal nerves form the lumbosacral plexus which gives rise to the sciatic nerve?

Back 8

L4-S3

Front 9

What nerve supplies sensory innervation to the posterior thigh then branches into the common peroneal and tibial nerves which innervate the entire leg and foot from just below the knee.

Back 9

sciatic nerve

Front 10

What are four technique approaches to the lumbosacral Block?

Back 10

1. The lumbar plexus nerve block (psoas compartment block)
2. Femoral nerve block
3. The 3 in 1 block
4. The sciatic nerve block (sacral plexus).

Front 11

Which lumbosacral block approach has a higher likelihood of anesthetizing all three major nerves of the lumbar plexus because it blocks the lumbar plexus at a more proximal location.

Back 11

The psoas compartment block

Front 12

What three nerves are blocked with the three in one Block approach?

Back 12

The femoral nerve
Lateral cutaneous nerve
The obturator nerve.

Front 13

What nerves constitute the lumbar plexus?

Back 13

Lateral femoral cutaneous, femoral, obturator

Front 14

What are the landmarks for the psoas block?

Back 14

Psoas: Initially the fourth lumbar spine is identified from its relationship to the iliac crests. Move cephalad to locate the L3 spinous process. From L3 move 5cm lateral to the midline and mark with “X”

Front 15

What are the landmarks for the Femoral block?

Back 15

Femoral: Palpate both the anterior superior iliac spine and the pubic tubercle; it can be helpful to draw a line to represent this area for this line will represent the inguinal ligament. The femoral artery should lie at the midpoint and slightly lateral of the inguinal ligament and it is necessary to locate this by feeling for the pulse at this poin

Front 16

How many branches does the femoral nerve have? What are the branches and what do they innervate?

Back 16

The femoral nerve divides into two branches. The anterior, or superficial, branch provides sensory innervation to the anterior thigh. The posterior, or deep, branch is mainly motor and innervates the quadriceps muscle, knee joint and medial ankle/foot.

Front 17

What is the main nerve of the lumbosacral plexus?

Back 17

Sciatic

Front 18

What spinal segments does the lumbosacral plexus arise from?

Back 18

L4 – S3

Front 19

What spinal segments does the lumbar plexus arise from?

Back 19

L2 – L4

Front 20

Absolute contraindications of lower extremity blocks?

Back 20

-Patient refusal
-Inability to get an informed consent
-Sepsis or infection at the site of needle placement
-Coagulopathy

Front 21

Relative contraindications for a lower extremity block?

Back 21

--Preexisting neurological deficit. (A complete neurological examination is always recommended).
--Significant anatomical distortion at the insertion site
--Inadequate experience in the technique.
--Surgeon preferences
--The presence of a prosthetic femoral artery graft is a relative contraindication to femoral nerve block.

Front 22

Potential complications of nerve blocks?

Back 22

--Intravascular injection/Toxicity
--Nerve damage
--Accidental epidural or spinal
--Pneumothorax
--Infection
--Catheter breakage
--Fluid leakage from catheter site
--Bleeding

Front 23

Definition of a dermatome?

Back 23

A dermatome is the area of skin innervated by the cutaneous branches of a single spinal nerve

Front 24

What spinal nerve does not participate in dermatomes?

Back 24

C1

Front 25

What are the landmarks for a femoral block of the lumbosacral plexus?

Back 25

Anterior superior iliac spine
Pubic Tubercle
Femiral

Front 26

Characteristics of the Lumbar Plexus?

Back 26

--Arises from L1-L4
--innervates the thigh, abdominal wall, and psoas muscle
--The major nerves are the femoral and the obturator

Front 27

Landmarks for the sciatic nerve block of the lumar plexus?

Back 27

--Greater trochanter of femur
--Sacral hiatus or PSIS
--Line 4 cm caudad perpendicular to and bisecting original line is insertion point