NERVE PLEXUSES & ITS ANAESTHETIC IMPLICATIONS

NERVE PLEXUSES IN HUMAN BODY & ITS BLOCKS ....AN ANAESTHETIC IMPLICATION.

1. NERVE PLEXUSES & ITS ANAESTHETIC IMPLICATIONS PRATYUSH KANTI MISRA 1 ST YR PG STUDENT DPT OF ANAESTHESIOLOGY MKCG MCH

2. Nerve plexus plexus -- a network of nerves, blood vessels or lymphatics. A nerve plexus is a system of connected nerve fibers that link spinal nerves with specific areas of the body. A plexus is like an electrical junction box, which distributes wires to different parts of a house .

3. NERVE PLEXUS ANATOMY     The nerve plexus is actually made up of a multitude of nerve branches. These branches come from the spinal nerves. A nerve plexus is composed of afferent and efferent fibers that arise from the merging of the anterior rami of spinal nerves and blood vessels.

4. NErVE PLEXUS STRUCTURE Once they connect, they break off again and develop the network of nerve fibers known as the nerve plexus. There are actually 4 of these nerve plexuses in the human body, the brachial plexus, cervical plexus, the sacral plexus and the lumbar plexus.   At the root of the limbs, the anterior rami join one another to form complicated nerve plexus. The cervical and brachial plexuses are found at the root of the upper limbs, and the lumbar and sacral plexuses are found at the root of the lower limbs.

5. The main function of a nerve plexus   The main function of a nerve plexus is to ensure that all areas of the body are innervated, thereby equipping each region with the ability to send and receive messages from the peripheral nervous system.

6. Spinal plexus At each vertebral level, paired spinal nerves leave the spinal cord via the intervertebral foramina of the vertebral column. There are five spinal nerve plexuses

7. 1 .a. C ervical plexus The cervical nerve plexus is a junction of small nerve fiber network that transports sensory information to the shoulder, neck and the head. Cervical Plexus—Serves the Head, Neck and Shoulders  The cervical plexus is formed by the ventral rami of the upper four cervical nerves and the upper part of fifth cervical ventral ramus. The network of rami is located deep within the neck. 

8. 1. b . the brachial plexus   The brachial plexus is formed by the ventral rami of C5–C8 and the T1 spinal nerves, and lower and upper halves of the C4 and T2 spinal nerves. The plexus extends toward the armpit (axilla ).  

9. 1 .c. Lumbar plexus Lumbar Plexus—Serves the Back, Abdomen, Groin, Thighs, Knees, and Calves   The lumbar plexus is formed by the ventral rami of L1–L5 spinal nerves with a contribution of T12 form the lumbar plexus. This plexus lies within the psoas major muscle. 

10. 1 .d. sacral plexus Sacral Plexus—Serves the Pelvis, Buttocks, Genitals, Thighs, Calves, and Feet The sacral plexus is formed by the ventral rami of L4-S3, with parts of the L4 and S4 spinal nerves. It is located on the posterior wall of the pelvic cavity .

11. 1 .e. Coccygeal Plexus   Coccygeal Plexus—Serves a Small Region over the Coccyx Originates from S4, S5, and Co1 spinal nerves. It is interconnected with the lower part of sacral plexus .  

12. 2. Autonomic plexuses Autonomic plexus can contain both sympathetic and parasympathetic neurons :   Celiac plexus (solar plexus)— Serves internal organs . The solar plexus, or celiac plexus, is a large cluster of nerves that relay messages from the major organs of the abdomen to the brain. These visceral organs are important to metabolism and to general life functioning . Auerbach's plexus — Serves the gastrointestinal tract . Meissner's plexus (submucosal plexus)— Serves the gastrointestinal tract

13. Other plexuses Some other plexuses include the hypogastric plexus , renal plexus , hepatic plexus , splenic plexus , gastric plexus , pancreatic plexus , and testicular plexus / ovarian plexus . choroid plexus infoldings of blood vessels of the pia mater covered by a thin coat of ependymal cells that form tufted projections into the third, fourth, and lateral ventricles of the brain; they secrete the cerebrospinal fluid. cystic plexus a nerve plexus near the gallbladder. dental plexus either of two plexuses (inferior and superior) of nerve fibers, one from the inferior alveolar nerve, situated around the roots of the lower teeth, and the other from the superior alveolar nerve, situated around the roots of the upper teeth.

14. The Spinal Nerves 31 pairs of spinal nerves (1st cervical above C1) mixed nerves exiting at intervertebral foramen Proximal branches Dorsal (posterior) root is sensory input to spinal cord Ventral (anterior) root is motor output of spinal cord Distal branches dorsal ramus supplies dorsal body muscle and skin ventral ramus to ventral skin and muscles and limbs meningeal branch to meninges , vertebrae and ligaments

15. Branches of a Spinal Nerve Spinal nerves: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral and 1 coccygeal . Each has dorsal and ventral ramus .

16. Spinal Nerve Roots and Plexuses

17. Cervical Plexus Formed by the anterior (ventral) rami of the cervical nerves C1-C4 with contribution C5. Supplies the skin and muscles of the head, neck and superior part of the shoulders and chest. Phrenic nerve arises from the cervical plexus & innervates the diaphragm.

18. The Cervical Plexus

19. Terminal Branches Superficial branches (Sensory) Lesser occipital (C2) – skin of scalp posterior and superior to ear. Great auricular (C2-C3) – skin anterior, inferior, and over ear and over parotid gland. Transverse cervical (C2-C3) – skin over anterior aspect of neck. Supraclavicular (C3-C4) – skin over superior portion of chest and shoulder.

20. CERVICAL PLEXUS BLOCK Two Types --- 1) SUPERFICIAL BLOCK 2) DEEP BLOCK INDICATIONS - 1) CAROTID ENDARTERECTOMY 2) SUPERFICIAL NECK SURGERY 3) THYROIDECTOMY 4) TRACHEOSTOMY

21. SUPERFICIAL CERVICAL PLEXUS BLOCK

22. Brachial Plexus The anterior (ventral) rami of spinal nerves C5-C8 and T1 form the brachial plexus. Extends inferiorly and laterally on either side of the last four cervical and first thoracic vertebrae through intervetebral foramen. Passes above the first rib posterior to the clavicle and then enter the axilla ( cervicoaxillary canal). The brachial plexus provide the entire nerve supply of the shoulder and upper limbs.

23. Five important nerves arise from brachial plexus are:. Axillary nerve Musculocutaneous nerve Radial nerve Median nerve Ulnar nerve

24. The brachial plexus is an arrangement of nerve fibres, running from the spine, formed by the ventral rami of the lower cervical and upper thoracic nerve roots it includes – from above the fifth cervical vertebra to underneath the first thoracic vertebra( C5-T1 ). It proceeds through the neck, the axilla and into the arm. The brachial plexus is responsible for cutaneous and muscular innervation of the entire upper limb. ANATOMY

25. The trunks pass laterally and lies around the subclavian artery while passing over the first rib to enter the axilla , between the clavicle and the scapula. Behind the clavicle, each trunk splits into anterior and posterior divisions . These recombine to form the posterior , lateral and medial cords around the axillary artery. The upper roots (C5–7) tend to stay lateral , the lower roots (C8,T1) tend to stay medial and All roots contribute to the posterior cord, and therefore also to the radial nerve.

26. In the neck , the brachial plexus lies in the posterior triangle , being covered by the skin, Platysma , and deep fascia;where it is crossed by the supraclavicular nerves, the inferior belly of the Omohyoid , the external jugular vein, and the transverse cervical artery. When It emerges between the Scaleni anterior and medius ; its upper part lies above the third part of the subclavian artery, while the trunk formed by the union of the eighth cervical and first thoracic is placed behind the artery. RELATIONS

27. FORMATION OF THE BRACHIAL PLEXUS

28. Roots The ventral rami of spinal nerves C5 to T1 are referred to as the roots of the plexus. Trunks Shortly after emerging from the intervertebral foramina , these 5 roots unite to form three trunks. –The ventral rami of C5 & C6 unite to form the Upper Trunk. –The ventral ramus of C 7 continues as the Middle Trunk. –The ventral rami of C 8 & T 1 unite to form the Lower Trunk.

29. •Divisions Each trunk splits into an anterior division and a posterior division. –The anterior divisions usually supply flexor muscles –The posterior divisions usually supply extensor muscles . Cords –The anterior divisions of the upper and middle trunks unite to form the lateral cord . –The anterior division of the lower trunk forms the medial cord . –All 3 posterior divisions from each of the 3 cords unite to form the posterior cord . –The cords are named according to their position relative to the axillary artery

30. Schematic representation of brachial plexus

31. Cutaneous distribution

32. From Nerve Roots Muscles Cutaneous R oots dorsal scapular nerve C5 rhomboid muscles and levator scapulae - R oots long thoracic nerve C5, C6 , C7 serratus anterior - U pper trunk nerve to the subclavius C5, C6 subclavius muscle - U pper trunk suprascapular nerve C5, C6 supraspinatus and infraspinatus - NERVE SUPPLY

33. Lateral Cord lateral pectoral nerve C5, C6, C7 pectoralis major (by communicating with the medial pectoral nerve ) - Lateral Cord musculocutaneous nerve C5, C6, C7 coracobrachialis , brachialis and biceps brachii becomes the lateral cutaneous nerve of the forearm Lateral Cord lateral root of the median nerve C5, C6, C7 fibres to the median nerve - From lateral cord

34. Posterior Cord upper subscapular nerve C5, C6 subscapularis (upper part) - Posterior Cord thoracodorsal nerve (middle subscapular nerve) C6, C7, C8 latissimus dorsi - Posterior Cord lower subscapular nerve C5, C6 subscapularis (lower part ) and teres major - POSTERIOR CORD BRANCHES

35. Posterior Cord Axillary Nerve C5, C6 Anterior Branch: Deltoid And A Small Area Of Overlying Skin Posterior Branch: Teres Minor And Deltoid Muscles Posterior Branch Becomes Upper Lateral Cutaneous Nerve Of The Arm Posterior Cord Radial Nerve C5, C6, C7, C8, T1 Triceps Brachii , Supinator , Anconeus , The Extensor Muscles Of The Forearm , And Brachioradialis Skin Of The Posterior Arm As The Posterior Cutaneous Nerve Of The Arm POSTERIOR CORD BRANCHES

36. Medial cord Medial pectoral nerve C8, t1 Pectoralis major and pectoralis minor - Medial cord Medial root of the median nerve C8, t1 Fibres to the median nerve Portions of hand not served by ulnar or radial Medial cord Medial cutaneous nerve of the arm C8, t1 - Front and medial skin of the arm MEDIAL CORD BRANCHES

37. Medial Cord Medial Cutaneous Nerve Of The Forearm C8, T1 - Medial Skin Of The Forearm Medial Cord Ulnar Nerve C8, T1 Flexor Carpi Ulnaris , The Medial 2 Bellies Of Flexor Digitorum Profundus , The Intrinsic Hand Muscles Except The Thenar Muscles And The Two Most Lateral Lumbricals The skin of the medial side of the hand medial one and a half fingers on the palmar side and medial two and a half fingers on the dorsal side MEDIAL CORD BRANCHES

38. The plexus may include anterior rami from C4 or T2 and these are designated as Pre fixed- C4 added Post fixed- T2 added. The connective tissue sheath that invests the plexus especially in the axillary region has a convoluted and septated structure that can lead to non uniform distribution of local anaesthetics . ANATOMIC VARIATIONS

39. Brachial plexus injury

40. Named after augusta déjerine-klumpke , klumpke's paralysis is a variety of partial palsy of the lower roots of the brachial plexus. Results from a brachial plexus injury in which C8 and T1 nerves are injured . Affects, principally, the intrinsic muscles of the hand and the flexors of the wrist and fingers. The classic presentation of klumpke's palsy is the “ claw hand” where the forearm is supinated and the wrist and fingers are hyperextended with flexion at interphalangeal joints. Klumpke s palsy

41. Erb's palsy ( Erb-Duchenne Palsy ) is a paralysis of the arm caused by injury to the upper trunk C5-C6. signs of Erb's Palsy include loss of sensation in the arm and paralysis and atrophy of the deltoid, biceps , and brachialis muscles. the arm hangs by the side and is rotated medially; the forearm is extended and pronated . commonly called " waiter's tip hand." Erb’s palsy

42. Erb’s Palsy – Nerves Affected

43. BRACHIAL PLEXUS BLOCK- Techniques- Interscalene Brachial Plexus Block Supraclavicular ( Subclavian )Brachial Plexus Block Infraclavicular Brachial Plexus Block Axillary Brachial Plexus Block Anesthetic implications

44. Described by winnie in 1970. Indications- 1) Surgery in shoulder ,upper arm and forearm. 2) Post operative analgesia for total shoulder arthroplasty Blockade occurs at the level of the upper and middle trunks . Interscalene block

45. Positioning - supine position with the head turned away from the side to be blocked. The posterior border of the sternocleidomastoid muscle is palpated by having the patient briefly lift the head. The interscalene groove can be palpated by rolling the fingers posterolaterally from this border over the belly of the anterior scalene muscle into the groove. A line extended laterally from the cricoid cartilage and intersecting the interscalene groove indicates the level of the transverse process of C6. The external jugular vein often overlies this point of intersection.

46. Complications Ipsilateral diaphragmatic paresis Severe hypotension and bradycardia (i.e., the Bezold-Jarisch reflex ) Inadvertent epidural or spinal block Nerve damage or neuritis intravascular injection with Seizure activity Horner’s syndrome with dyspnea and hoarseness of voice. Puncture of the pleura may cause Pneumothorax . Hemothorax . Hematoma and Infection.

47. Indications 1) operations on the elbow, forearm, and hand. Blockade occurs at the distal trunk–proximal division level. Location- The three trunks are clustered vertically over the first rib cephaloposterior to the subclavian artery. The neurovascular bundle lies inferior to the clavicle at about its midpoint. Supraclavicular block

48. Technique- in supine position with the head turned away from the side to be blocked. The arm to be anesthetized is adducted, and the hand should be extended along the side toward the ipsilateral knee as far as possible. In the classic technique , the midpoint of the clavicle is identified . The posterior border of the sternocleidomastoid is felt. The palpating fingers can then roll over the belly of the anterior scalene muscle into the interscalene groove, where a mark should be made approximately 1.5 to 2.0 cm posterior to the midpoint of the clavicle. Palpation of the subclavian artery at this site confirms the landmark.

49. Indications - Hand, wrist, elbow and distal arm surgery Blockade occurs at the level of the cords of the musculocutaneous and axillary nerves . Anatomical landmarks : The boundaries of the infraclavicular fossa are pectoralis minor and major muscles anteriorly , ribs medially , clavicle and the coracoid process superiorly, and humerus laterally. Infraclavicular block

50. Technique- Classic approach The needle is inserted 2 cm below the midpoint of the inferior clavicular border, advanced laterally and directed toward the axillary artery A coracoid technique consisting of insertion of the needle 2 cm medial and 2 cm caudal to the coracoid process has also been described

51. Infraclavicular approach

52. Indications – include surgery on the forearm and hand. Elbow procedures are also successfully performed with the axillary approach. Blockade occurs at the level of the terminal nerves. blockade of the musculocutaneous nerve is not always produced with this approach. Axillary approach

53. Axillary block

54. Landmark- The axillary artery is the most important landmark; the nerves maintain a predictable orientation to the artery. The median nerve is found superior to the artery, the ulnar nerve is inferior, and the radial nerve is posterior and somewhat lateral At this level, the musculocutaneous nerve has already left the sheath and lies in the substance of the coracobrachialis muscle.

55. Technique - The patient should be in the supine position with the arm to be blocked placed at a right angle to the body and the elbow flexed to 90 degrees. A transarterial technique can be used whereby the needle pierces the artery and 40 to 50  mL of solution is injected posterior to the artery; alternatively, half of the solution can be injected posterior and half injected anterior to the artery. Field block of the brachial plexus with a fanlike injection of 10 to 15  mL of local anesthetic solution on each side of the artery is a variation of the sheath technique.

56. Lumbosacral plexus Lumbosacral plexus is basically combination of two plexus, Lumbar Plexus & Sacral Plexus. LUMBAR PLEXUS: The lumbar plexus is formed by the ventral rami of first four lumbar nerve roots (L1, L2, L3 (major) & part of L4). In 50% of cases it receives a contribution from the ventral rami of last thoracic root (T12). L.S Plexus by IM

57. Components of lumbosacral plexus Components of the lumbosacral plexus are as, 1. Lumbar plexus L1, L2, L3, L4 2. Lumbosacral Trunk L4, L5 The above roots contribute in lumbar and sacral plexus both. 3. Sacral Plexus S1, S2, S3, S4 Smaller branches of the lumber plexus innervate the posterior abdominal wall and psoas muscles (psoas major, iliacus). Main branches innervate the anterior thigh and their relative muscles. Key to remember. Root →Branches→Divisions→ Terminal Branches (RBDT) L.S Plexus by IM

58. Root : these are constituted by the anterior primary rami of L1, L2, L3, L4 (T12). Branches : L1 root gives an upper and lower branch L2 Root gives and upper and lower branch L3 does not give any branch L4 gives an upper and lower branch Division: Lower branch of L2, upper branch of L4 and ventral rami of L3 nerve roots divide into small anterior and large posterior division. From L2 and L3 each gives two and L4 one posterior divisions, with single anterior division from all branches (L2, L3, L4). Lower branch of L4 and L5 unite to form lumbosacral trunk L.S Plexus by IM

59. Terminal Branches of Lumbar Plexus L1 unites with a small branch from T12 and splits into an upper and lower branch es . The upper larger branch divides into two: iliohypogastric ( T12, L1) and ilioinguinal nerves ( L1 ) . The lower smaller branch of L1 unites with a branch from L2 to form the genitofemoral nerve . The remainder s of L2, L3 and L4 divide into ventral and dorsal branches. Ventral (Anterior) divisions of L2, L3, L4 unite to form obturator nerve . The dorsal (posterior) divisions of L2 and L3 divide into small and larger parts. Smaller parts of dorsal divisions of L2 and L3 unite to form the lateral femoral cutaneous nerve. Larger parts of dorsal divisions of L2 and L3 unite with L4 to form femoral nerve. L.S Plexus by IM

60. L.S Plexus by IM

61. FEMORAL NERVE It is formed by the dorsal or posterior division of the anterior rami of L 2, L 3, & L 4 roots. The femoral nerve is the largest branch of the lumbar plexus. It mainly supplies the extensors muscles of the knee (quadriceps) (VL, VI, VM, RF). The Saphenous Nerve is a purely sensory nerve which the largest and longest cutaneous branch of the femoral nerve. Lateral femoral cutaneous nerve of the thigh The lateral femoral cutaneous nerve of the thigh emerges from the lateral border of psoas major which is formed by the posterior divisions of L2 and L3. . It gives cutaneous supply to the lateral part of the thigh. L.S Plexus by IM

62. Gentiofemoral Ileohypogstric / ileoinguinal Lat .Fem. Cut. Nerve of thigh Femoral (Anterior & Medial Cut. Nerves) Obturator Sensory Sciatic Superficial peroneal Nerve Sural Saphenous Sensory Distribution of the Lower Limb L.S Plexus by. IM. 12-08-2014 76

63. L.S Plexus by IM

64. LUMBO-SACRAL TRUNK & SACRAL PLEXUS The sacral plexus is formed by the lumbosacral trunk (L 4 ,L 5 ), & ventral rami of S 1, S 2, S 3, S 4 . Contribution of the fourth sacral ventral rami is partial & the remainder of the last (S 5 ) joins the coccygeal plexus. Key to remember sacral plexus: Root  Divisions  Terminal Branches (R.D.T/B) Roots: These are constituted by the anterior primary rami of L 4 , L 5, S 1, S 2, S 3, & S 4 Divisions: The lower branch of L 4 ventral rami & ventral rami of L 5 , S 1 & S 2 give anterior and posterior divisions. While S 3 forms & shares only anterior division . Terminal Branches : These anterior and posterior divisions unite to form the terminal nerve branches. L.S Plexus by IM

65. Terminal Branches The posterior division of L 4 ,L 5 & S 1 joins to form Superior Gluteal Nerve . The posterior divisions of L 5 ,S 1 & S 2 unites to form the Inferior Gluteal Nerve. The posterior divisions of L 4 ,L 5 ,S 1 & S 2 joins to form Common fibular or Peroneal Nerve . It’s the about one-half the size of the tibial nerve . The anterior divisions of L 4 ,L 5 ,S 1 ,S 2 & S 3 unites to form Poterior Tibial Nerve. The anterior divisions of S 2 ,S 3 & S 4 unites to form Pudendal Nerve . So both these nerves i.e. Tibial and peroneal run in a single covering of sheath and called as Sciatic Nerve (L 4 ,L 5 ,S 1 ,S 2 &S 3 ) . Which is the largest nerve of the body. L.S Plexus by IM

66. L.S Plexus by IM

67. Nerve Name Origin Supplies Iliohypogastric T12,L1 Motor supply to internal oblique, transverses muscles, sensation over lower anterior abdominal wall Ilioinguinal L1 Sensation over anterior pubis (mons) and anterior scrotum or labia Genitofemoral L1, L2 Genital branch: motor supply to cremastor muscle, sensation to anterior scrotum; femoral branch: sensation to anterior thigh Femoral L2, L3, L4 Motor supply to extensors of the knee, sensation to anterior thigh Obturator L2, L3, L4 Motor supply to adductors of the thigh, sensation to medial thigh Lumbosacral trunk L4, L5 Joins the sacral nerves to form the lumbosacral plexus that supplies motor and sensory innervations to the lower extremities Posterior femoral cutaneous S2, S3 Sensation to perineum, posterior scrotum, and posterior thigh Pudendal S2, S3, S4 Motor to levator ani, muscles of the urogenital diaphragm, anal and striated urethral sphincter, sensation to the perineum, scrotum, and penis L.S Plexus by IM

68. 12/08/2014 Nerve Name Origin Supplies Nerve to quadratus femoris L4,L5,S1 quadratus femoris, inferior gemellus Superior gluteal L4,L5,S1 gluteus medius & minimus, tensor fasciae latae Inferior gluteal L5,S1,S2 Gluteus maximus Nerve to obturator internus L5,S1,S2 obturator internus, superior gemellus Sciatic sacral plexus (ventral primary rami of L4-L5, S1-S3) (via its tibial & common peroneal branches) semitendinosus, semimembranosus, biceps femoris, part of adductor magnus, muscles of leg & foot skin of leg & foot (excluding medial side of leg & foot) L.S Plexus by IM

69. Sciatic Nerve Sciatic Nerve descends along the back of the thigh and through the middle of the popliteal fossa , to the lower part of the Popliteus muscle. It divides just 5cm above the politial fossa into Common Peroneal & Tibial nerves to supply their relative muscles. L.S Plexus by IM

70. Sensory Distribution to the Legs: Superficial Peroneal: it’s the cutaneous branch from the common peroneal nerve which supplies to the antero-lateral aspect of leg upto dorsum of the foot. Sural nerve formed by the junction of the medial sural cutaneous (it is the sensory branch of tibial nerve) with the peroneal anastomotic branch (its branch of lateral sural cutaneous nerve), passes downward near the lateral margin of the tendo-calcaneous , lying close to the small saphenous vein, to the interval between the lateral malleolus and the calcaneous . It supplies to the postero -lateral aspect of the leg upto lateral malleolus . L.S Plexus by IM

71. Lat femoral obturator

72. LUMBAR PLEXUS BLOCK Approaches- 1) WINNIE’S approach- Lateral 2) CHAYEN’S approach- paravertebral , medial 3) CAPDEVILA’S approach

73. PSIS TUFFIER’S LINE SPINOUS PROCESSES WINNIE’S APPROACH

74. SACRAL PLEXUS BLOCK Approaches- 1) MANSOUR’S approach 2) REAL SACRAL PLEXUS BLOCK- cr 1/3,cd 2/3 3) PARASACRAL approach 4) SCIATIC NERVE BLOCK- LABAT’S approach RAJ’s approach

75. COELIAC PLEXUS BLOCK Indications - for relief of pain e.g 1) ACUTE PAIN- post op pain 2) CHRONIC PAIN – chronic pancreatitis 3) CANCER PAIN – carcinoma pancreas

76. THANK YOU