Maverick Modules (23-26) PENG, LFCB, & PSB

Question 1

What are indications for a PENG (Pericapsular Nerve Group) block?

Answer 1

Anything involving Hip Joint & Femoral Neck

• Hip arthroscopy
• Total Hip Replacement
• Femoral Neck Fracture

Question 2

What are the advantages of a PENG block?

Answer 2

• ↓ Opioids
• ↓ MAC (especially good for elderly)

Question 3

PENG block can be combined with ___________ block to provide complete analgesia for many hip procedures.

Answer 3

LFCN (Lateral Femoral Cutaneous Nerve)

Question 4

What makes PENG blocks superior to Fascia Iliaca (FICB) and Lumbar Plexus (LP) blocks?

Answer 4

PENG will reliably anesthetize obturator nerve branches that are missed by FICB and LPB’s.

Question 5

What are the contraindications for PENG block?

Answer 5

• Patient Refusal
• Infection at site
• LA allergy
• Severe Bleeding Disorder (Relative contraindication because this is a compressable space)

Question 6

What does AIIS stand for in the picture below?
What does the red line indicate?

Answer 6

• Anterior Inferior Iliac Spine
• Field of where you need your LA to spread

Question 7

What nerve (and origins) are noted by the green line below?

Answer 7

Obturator Nerve (L2-L4)
innervated IL and IM quadrants, but mostly IM quatdant

Question 8

What nerve (and origins) are noted by the blue line below?

Answer 8

Accessory Obturator Nerve (L3-L4)
50/50 innervating SM and IM quadrants of the hip joint

Question 9

What nerve (and origins) are noted by the yellow line below?

Answer 9

Femoral Nerve (L2-L4)
usually all 4 quadrants of the hip capsule, but not every time

Question 10

When performing a PENG block, the ultrasound probe should be parallel to the ____.

Answer 10

Inguinal Crease

Question 11

What dose of LA is necessary for post-op pain control with a PENG block?
What dose would be necessary for surgical analgesia?

Answer 11

10-20mL of…

Question 12

Failure to capture ____ nerve may be interpreted as a failed PENG block. (Though it is not)

Answer 12

Lateral Femoral Cutaneous Nerve
This lateral incisional pain could be interpreted as a block failure, but really its just a different nerve - therefore, add a lateral femoralcurantous block to get complete analgesia

Question 13

What are indications for LCFN (Lateral Cutaneous Femoral Nerve) Block?

Answer 13

• Surgical Incision on lateral thigh
• Adjunct to other blocks (Typically PENG)

Question 14

Probe placement for LFCN block

Answer 14

Parallel and along the inguinal crease (only move the probe medial or lateral along the inguinal crease)
- Find the femoral a., find the TFL about at the 1cm depth mark
- then move laterally along the inguinal crease until you come to the sartorius m. to find the LFCN

Question 15

Where is the LFCN in relation to the sartorius?

Answer 15

About 1cm superficial to the sartorius

Question 16

How much volume of LA is necessary for an LFCN block?

Answer 16

5 - 10 mL

Question 17

How deep is the LFCN likely to be?

Answer 17

1 - 1.5 cm

Question 18

What are the two bifurcations of the sciatic nerve?

Answer 18

• Tibial nerve
• Common Peroneal nerve

Question 19

What is the most desirable motor response elicited from a popliteal sciatic nerve block?

Answer 19

Inversion (indicates stimulation of both tibial and deep peroneal)

Question 20

Tibial nerve stimulation elicits what motor response?

Answer 20

Plantarflexion

Question 21

Common Peroneal nerve stimulation elicits what response?

Answer 21

Dorsiflexion/Eversion

Question 22

How to scan for the PSB?

Answer 22

• Start with your probe in the short axis (transversely) 3-5 cm depth
• locate the popliteal a - then look superiorly to the artery and ID the two hyperechoic nerves (deep peroneal and tibial)
• scan cephalidly until you come to the bifircation of the sciatic - this is where you want to inject

Question 23

Needle approach for PSB

Answer 23

You want to do an in place approach, so make sure to turn your probe before you stick

Question 24

Because the medial area of the lower leg is innervated by the femoral nerve, it is not adequately anesthetized by the popliteal SNB. What can be done to facilitate blocking the medial maleolus?

Answer 24

Combine a saphenous or adductor canal block with the PSB