1. Dr S. Parthasarathy MD DA DNB PhD FICA , Dip software based statistics
Lumbar plexus blocks
Dr S. Parthasarathy MD DA DNB PhD FICA , Dip software based statistics

2. Hence we go for spinal or epidural !!
Upper limb
One brachial plexus
Easy to access
Easy to test and administer
Lower limb
Lumbar and sacral plexus
Difficult to access
Late onset .

3. Anatomy
The lumbar plexus is an anastomotic complex formed by the anterior roots from L1 to L3 and the greater part of L4.
There is frequent anastomosis between the upper part of the plexus with the subcostal nerve and between the L4 rami and the lumbosacral trunk ( nervi fucralis)
Into the psoas – from the psoas

6. Anatomy
The plexus passes peripherally after its exit from the intervertebral foramina, usually covered by the psoas muscle
The genitofemoral nerve and the lateral cutaneous nerve of the thigh leave the plexus soon after the iliohypogastric and ilioinguinal nerves have split off.

7. The first lumbar nerve, which contains a branch from the twelfth thoracic nerve, divides into an upper branch
(iliohypogastric nerve and ilioinguinal nerve) and a lower branch (genitofemoral nerve)..

8. Most of the second, third, and parts of the fourth lumbar nerves form ventral branches, from which the femoral nerve and obturator nerve branch
The lateral femoral cutaneous nerve is formed from fibers of the ventral branches of L2/L3.

9. Nerves iliohypogastric Ilioinguinal Genitofemoral
Lateral femoral cutaneous
Femoral
Obturator

10. The iliohypogastric nerve penetrates the transversus abdominis muscle near the crest of the ilium and supplies motor fibers to the abdominal musculature.
It ends in an anterior cutaneous branch to the skin of the suprapubic region and a lateral cutaneous branch in the hip region

12. Femoral
The femoral nerve(L2/L4) is the largest nerve of the lumbar plexus and provides the sensory innervation of the front of the thigh, while its sensory terminal branch, the saphenous nerve, innervates the inside of the lower leg as far as the ankle. The femoral nerve passes anterior to the psoas muscle under the inguinal ligament through the muscular lacuna and is the motor nerve for the quadriceps femoris, sartorius, and pectineus muscles.

13. The lateral cutaneous nerve of the thigh (L2/3) passes over the iliacus muscle medial to the anterior superior iliac spine under the inguinal ligament and is a purely sensory nerve innervating the skin on the lateral side of the thigh.

14. The obturator nerve(L2/L4) leaves the plexus medial to the psoas muscle and passes through the obturator canal together with the obturator vein and artery to the inside of the thigh
Anterrior and posterior branches
Supply adductors
Medial side of knee – skin innervation

19. Clinical Assessment of Lower Extremity Nerve Blocks
push, - tibial
pull, - common peroneal
pinch- lateral femoral cutaneous
Punt – femoral

20. push, pull, pinch, punt.

21. Indications Anesthesia- wound care, SSG, muscle biopsy
Analgesia – positioning before spinal or periop analgesia
CRPS
Vasoocclusive disease
Postamputation pain
Edema in the leg after radiotherapy
Diabetic polyneuropathy

22. How to block plexus Psoas compartment block Three in one inguinal
perivascular block

23. CHEYEN technique
Psoas compartment block

24. Position : Lateral, with the surgical side up.
Common Indications: Anesthesia and immediate postoperative analgesia for hip, femur, or knee surgery.
Needle Size: 21-gauge, 100-mm insulated needle.
Volume: 20 to 30 mL 0.5% or 0.2% ropivacaine depending on the indication.

25. Intercristal line – PSIS cross – 4 cm from midline

26. Needle perpendicular
4- 5 cm – transverse process
Cranially – cross quadratus
1.5 mA current
Hamstring contraction
0.5 mA
Inject slow

27. Psoas muscle – hip contraction – withdraw
Abdominal muscle – ILIH - go lateral
No bone – go medial
Labial paresthesia – genitofemoral - go lateral
Erector spinae – go deep
Hamstring muscles = go cranially

28. Usually 30 ml
Onset may be minutes
Medial side knee – sensory loss – saphenous sign
Sedation with midazolam and fentanyl is ideal
Quadriceps and adduction thigh
Monitor 45 minutes
Other side sensory testing

30. MRI picture and flow of local anesthetics
Proved obturator block in 90 %

32. Continuous plexus blocks
Touhy needle
Quadriceps contraction
Catherter cranial 8 cm in
5 ml / hour infusion of dilute ropivacaine
PCA 5ml/ 30 minutes

33. Toxicity – may be there because of muscle compartment and large volume
Nerve injury – rare
Vascular injury – rare
Epidural – may be there and hypotension – with resuscitative ready
Usually unilateral sympathectomy – no hemodynamic consequences

34. Femoral , LFCN and obturator
Three in one block
Femoral , LFCN and obturator
Attack from below

35. Winnie description first
Cephalad flow along a fascial layer
supine with both legs extended and the leg to be blocked with 15–30 degrees lateral rotation.
Nerve stimulation and quadriceps twitch
USG

37. Iliopsoas or bone hit – come superficial
Sartorius – go deep and lateral
Vessel – femoral artery – go lateral
No response – gone too lateral – come medial
Usually 20 ml
Not much sedation required
Obturator may be missed

38. Femoral nerve block
The femoral nerve enters the thigh at the level of the inguinal ligament lateral to the femoral artery,
divides slightly distal to the inguinal ligament in branches,
insert close to the distal ligament when performing the 3-in-1 block.
The femoral nerve supplies motor branches to the quadriceps femoris, sartorius, and pectineus muscles, and its sensory branch (saphenous nerve) innervates the anterior-medial side of the lower leg down to the medial ankle

39. Just below inguinal ligament
Lateral to femoral
artery
Perpendicular insertion
Quadriceps contraction
OR USG

40. Probe vessels and the nerve

41. Femoral Vs 3 in one
Operations on the anterior thigh (i.e. lacerations, skin graft, muscle biopsy)
Pin or plate insertion/removal (femur)
Femur fractures
Same indications as femoral nerve block
Analgesia and anesthesia of the hip (dislocations, femoral neck fractures)
Analgesia of the knee
Volume and distal pressure

42. Lateral femoral cutaneous nerve
The lateral femoral cutaneous nerve (LFCN) divides into approximately two to five branches innervating the lateral and upper aspects of the thigh.
Pain relief
Meralgia paresthetica
SSG

43. The lateral femoral cutaneous nerve typically is located between the tensor fasciae latae (TFLM) and sartorius (SaM) muscles, 1 to 2 cm medial and inferior to the anterior superior iliac spine (ASIS) and 0.5 to 1.0 cm deep to the skin surface
1 ml is enough

44. Obturator nerve block
treat hip joint pain and is used in the relief of adductor muscle spasm associated with hemiplegia or paraplegia,
cerebrovascular pathology,
medullar injuries,
multiple sclerosis, and infantile cerebral palsy.
Possible in TURBTs

45. 1.5 cm caudad and lateral to pubic tubercle
2 – 4 cm – anterior
Slide posterior
Pubic ramus
Cranial and lateral 2 cm
10 ml local
Weak adduction

47. Summary Lumbar plexus – anatomy and the main nerves
Indications - Types of blocks
Procedure and tricks
Three in one
Femora, LFCN and obturator

48. Thank you all