This document provides an overview of brachial plexus anatomy and techniques for brachial plexus nerve blocks. It begins with a description of the brachial plexus formation from cervical and thoracic nerve roots and its branching pattern. Four main approaches for brachial plexus nerve blocks are described: interscalene, supraclavicular, infraclavicular, and axillary. Details are provided on the anatomy and techniques for performing interscalene and supraclavicular brachial plexus blocks. Ultrasound guidance is discussed as an advancement which allows real-time visualization of needle and nerve. Complications are also summarized.

1. Dr.ZIKRULLAH

2. Introduction
 Surgical anaesthesia of the upper extremity and shoulder
can be obtained following neural blockade of the brachial
plexus (C5-T1) or its terminal branches at several sites.
 Long back in 1884, first brachial block was done by
Halstead under direct vision using cocaine.

3.  The fascial sleeve derived from the prevertebral and
scalene fascia encloses the brachial plexus which extends
from the intervertebral foramina to the upper arm.This and
the branching pattern serves as the anatomic basis for
brachial plexus blocks.
 Injection into this sheath allows local anesthetic to spread
and block C5–T1 nerve roots. The degree of neural
blockade, however, may vary depending on the level of
injection.

4. Anatomy
 The brachial plexus is formed by the union of the anterior
primary divisions (ventral rami) of the fifth through eighth
cervical nerves (C5,C6,C7,C8 ) and first thoracic (T1)
nerve, with variable contributions from C4 and T2.
 It consists of roots, trunks, divisions, cords and terminal
branches.

5.  The roots of the plexus (anterior primary rami of C5-T1
nerves) are between the scalene muscles, the trunks in the
posterior triangle, the divisions behind the clavicle, and
the cords arranged around the second part of axillary
artery.
 About 10% of plexuses are prefixed (from C4-C8) and
10% postfixed (from C6-T2).

6. COURSE
• The nerves roots leave the intervertebral foramina and
course anterolaterally and inferiorly to lie between the
anterior and middle scalene muscles.
• Between these muscles, these nerve roots unite to form
3 vertically arranged trunks- upper(C5,C6), middle(C7),
lower(C8,T1).

8.  As the trunks pass over the lateral border of the first rib
and under the clavicle, each divides into anterior and
posterior divisions.
 The divisions pass posterior to the middle of the clavicle
to enter the axilla.
 Here they combine again to form three cords which are
named according to their relationship to the second part of
axillary artery.

9.  Lateral cord- formed by the union of anterior divisions of
superior and middle trunks.
 Medial cord- formed by the anterior division of inferior
trunk.
 Posterior cord- formed by the posterior divisions of all
three trunks.

11. Approaches for Brachial Plexus
Block
 Interscalene Brachial Plexus Block.
 Supraclavicular(Subclavian)Brachial Plexus Block.
 Infraclavicular Brachial Plexus Block.
 Axillary Brachial Plexus Block.

12. Approaches of Brachial Plexus Block
Interscalene Brachial Plexus Block
 Classic Technique (Winnie)
 Modified Lateral Technique (Meier)
 Modified Lateral Technique (Borgeat)
 Posterior/cervical Approach .

13. Supraclavicular Brachial Plexus Block
 Classical technique of Kulencampff
 Modified Plumb-bob approach
Infraclavicular Brachial Plexus Block
 Classic approach
 Coracoid approach
 Vertical Infraclavicular Block

14. Axillary Brachial Plexus Block
 Single /Double /Multiple-Injection Technique
 Transarterial technique
 Midhumeral Approach.

15. Typical Areas of Block

16. Technique of brachial plexus block
1. Elicitation of paresthesia.
2. Nerve stimulation technique.
3. Ultrasonography (USG) guided brachial plexus block.

17. Elicitation of paresthesia
 When a needle makes direct contact with a sensory
nerve, a paresthesia is elicited in its area of distribution.
 With this technique, it is important to ascertain that the
needle is making contact with the nerve rather than
penetrating it.
 Local anaesthetic(LA) solution is injected in the
proximity to the nerve (perineural) rather than with in its
substance( intraneural).

18. Nerve stimulation technique
 Low-level electrical current applied from the tip of a needle
can elicit specific muscle contractions when the needle is in
close proximity to a motor nerve.
 Once the desired twitch is obtained, the needle is carefully
manipulated, while reducing the current until the twitch
disappears.
 Obtaining a twitch at a current 0.4 - 0.5mA but not <0.2 mA
is a popular technique.
 The needle is held immobile and 1 ml of the local
anaesthetic is injected. At this point the twitching should
disappear. Total LA solution is injected with intermittant
aspiration.

20. USG guided brachial plexus block
 Despite of time tested record of safety of these blind
techniques, there exists an inherent rate of block
failure and complications, including LA toxicity due
to intravascular injection and nerve damage - caused
by mechanical trauma and/or intraneural injection.
 The major advantage of USG guidance is it affords
real time visualization of needle , nerve and
surrounding vasculature.

21. ULTRASOUND TECHNIQUE
 The optimal transducer used varies depending upon the
depth of the target nerve and the approach angle of the
needle relative to the transducer.
 High frequency transducers provide high resolution
picture but offer poor tissue penetration and therefore used
for superficial nerves.
 Low frequency transducers provide an image of poorer
quality but have better tissue penetration and used for
deeper structures.

22.  Nerves are best imaged in cross section, where they
have a characteristic honey comb appearance.
 Needle insertion can pass parallel (in plane approach)
or not parallel (out of plane approach) to the plane of
ultrasound waves.

23.  With the in plane approach the needle enters the skin
at the side of the probe . The needle traverses the
plane of ultrasound and the whole shaft is visualised
as it progresses towards the target.
 With the out of plane approach the needle enters the
skin away from the probe and is aimed at the plane of
sound and just the needle tip is visualised and rest of
needle is off the screen

24.  In US guided nerve block all anatomical structures in the
target area are visualized. The penetration depth and the
position of focal zones is optimized.
 Once the needle is optimally placed, LA is administered
under direct sonographic visualization until the nerve
structures are surrounded by LA.
 If the LA does not spread in the right direction , the
needle can be repositioned accordingly.
 It can also be used to guide the placement of catheter for
continuous nerve blocks.

25. Sonographic view of an artery,vein and nerve

26. Advantages of USG guided nerve
blocks
 Direct visualization of nerve and surrounding
structures.
 Direct visualization of spread of LA injection.
 Avoidance of side effects- intraneuronal and
intravascular injections.
 Avoidance of painful muscle contractions during
nerve stimulation( in cases of fractures).
 Reduction of the dose of LA .
 Faster sensory onset time.
 Longer duration of blocks.
 Improved quality of block and patient’s comfort.

27. Figure 2. An example of the ultrasound-guided needle-advancement technique showing one
hand holding the probe and the other hand holding the insulated needle in the left
supraclavicular location (A) anteroposterior view and (B) aerial view.

28. Figure 1. Transverse sonogram in the supraclavicular region showing the brachial plexus as a
group of hypoechoic nodules (N with arrows) lateral to the subclavian artery (SA) and cephalad
to the first rib (R).
Chan V W S et al. Anesth Analg 2003;97:1514-1517
©2003 by Lippincott Williams & Wilkins

30. Interscalene Anatomy
SCM
Middle Scalene
Anterior Scalene
Omohyoid

31. INTERSCALENE BLOCK
 INDICATIONS:
Major indication is shoulder
surgery since the block is most
intense at upper and middle
trunks (C5-C7).
Blockade of inferior trunk is
often incomplete. Hence it can
be used for forearm and hand
surgery after supplementing
ulnar nerve block.

32. PROCEDURE
 Patient is placed in supine position with head turned
slightly to the contralateral side.
 Posterior border of sternocleidomastoid is palpated by
having the patient briefly lift his head.
 Interscalene groove is palpated by rolling the fingers
posterolaterally from this border over the belly of the
anterior scalene muscle into the groove.

33. 33

34.  A line is extended laterally from the cricoid cartilage
to intersect the interscalene groove indicating the level
of transverse process of C6 vertebra.
 Under sterile precautions local anaesthetic is injected
at this point and a skin wheal is raised.
 A 22-25 G, 4 cm needle is introduced perpendicular to
the skin and advanced in slightly medial and caudal
direction until a paraesthesia or evoked muscle
contraction in arm is elicited.
34

36.  If bone is encountered within 2 cm of skin, it is likely
to be a transverse process and the needle may be
‘walked’ across this structure to locate the nerve.
 Contraction of the diaphragm indicates phrenic nerve
stimulation and anterior placement of needle. It should
be redirected posteriorly to locate the brachial plexus.
36

37.  After appropriate paraesthesia or motor response is
obtained, the needle is stabilized. After negative
aspiration, 10-40 ml of solution is injected.
 Digital pressure above the injection site and
downward massage along with a 45 degree head up
position may facilitate caudal spread and blockade of
the lower trunk.

38.  This was the initial technique for brachial block,
described by WINNIE in 1970.
 This approach was later modified by MEIER.
 In this modification, the puncture point is at the
posterior edge of sternocleidomastoid, but located 2-3
cm more cranially at the level of the superior thyroid
notch.
 The needle is directed caudally at 30 degrees to the
skin and slightly lateral, aiming for the mid to lateral
point of clavicle.
38

39. Modified lateral approach of BORGEAT
 The insertion point is same as Winnie approach, i.e. in
the interscalene groove, just behind
sternocleidomastoid at the level of cricoid cartilage,
but the needle is directed along the interscalene space,
towards the posterior part of the superior or middle
trunk (in order to elicit triceps contraction).
39

40. Borgeat Approach

41. CERVICAL/POSTERIOR APPROACHES
KAPPIS / PIPPAApproach
 The site of insertion is at the back of the neck.
 Head is flexed maximally and the spinous processes
of C6 and C7 are palpated.
 A horizontal line of 3 cm drawn laterally, midway
between C6 and C7 vertebrae.
41

44.  After connecting a nerve stimulator, a 10 cm insulated
needle is inserted in a sagittal plane (aiming for the
cricoid cartilage).
 Contact is made with the transverse process of C7
vertebra after 5-6 cm.
 The needle is then redirected more cranially and
brachial plexus is located after 6-8 cm.( this is
confirmed by muscle contractions )
44

45. CONTINOUS INTERSCALENE BLOCK
Continuous interscalene block (CISB) may also be
performed for procedures with anticipated ongoing pain.
 The in-plane or out-of-plane approach of ultrasound
may be used for CISB.
Local anaesthetic spread can be observed in real time
during catheter injection to help confirm correct
positioning.

46. P.N.REDDY-HYCOME 2004
CONTINOUS INTERSCALENE BLOCK

47. COMPLICATION
 Hemidiaphram paralysis (phrenic nerve
blockade)
 100% of interscalene blocks
 May cause dyspnea, even respiratory failure,
depending on severity of underlying lung
disease
 Hoarseness (recurrent laryngeal nerve
blockade)
 Horner’s syndrome (stellate ganglion
blockade)
 Inadvertant epidural or intrathecal
puncture.
 Verebral artery injection

49. AnteriorPosterior

51. Indications:Indicated for operations on the elbow,
forearm and arm.
 Blockade occurs at the level of distal trunks and
proximal divisions
 the brachial plexus is compact at this point and a
small volume of solution produces rapid onset of
reliable blockade.
51

52. TECHNIQUE
Patient is placed supine with head turned towards the
contralateral side.
Midpoint of the clavicle should be identified and
marked.
The posterior border of sternocleidomastoid can be
easily palpated by asking the patient to raise his head
slightly.
The palpating fingers must be then rolled over the
belly of the anterior scalene muscle, into the
interscalene groove, where a mark should be made
approx. 1.5-2.0 cm posterior to the midpoint of the
clavicle.

53. The trunks divide
behind
the clavicle into
anterior
and posterior divisions,
which separate the
innervation of the
ventral and dorsal
halves of the upper
limb.

54.  Palpation of the subclavian artery at this site confirms
the landmark.
 After raising a skin wheal of LA at this site, a 22-G, 4
cm needle is directed in a caudal, slightly medial and
posterior direction till a paraesthesia or motor
response is elicited or the 1st rib is encountered.
 If rib is encountered without elicitation of
paraesthesia, the needle can be ‘walked’ anteriorly or
posteriorly along the rib.
54

55.  If the artery is located, the needle can be withdrawn
and reinserted in a more posterolateral direction.
 On localization of the plexus, aspiration for blood
should be performed before incremental injections of
a total volume of 20-30 ml of the solution.
This was the classic supraclavicular approach of
Kulencampff
55

57. Two other supraclavicular approaches have been
mentioned:
1) The subclavian perivascular approach of Winnie and
Collins- the subclavian artery is palpated immediately
lateral to the clavicular head of sternocleidomastoid at
the level of the cricoid cartilage (C6 vertebra).
 A 3-4 cm needle is inserted behind the subclavian
artery and after eliciting muscle contractions 40 ml of
LA is injected.

58. 2) The Modified lateral paravascular approach of
Moorthy:
 Positioning is the same as for classic approach.
 The course of subclavian artery from above to below
the clavicle and into the axilla is marked.
 The needle is advanced along and parallel to the
surface marking of subclavian artery, laterally and
posteriorly, the tip of needle being directed towards
the axilla and away from the pleura, inferior to the
subclavian artery.

59. THE MODIFIED PLUMB-BOB
APPROACH
 The needle entry site is at the point where the lateral
border of the sternocleidomastoid muscle inserts
into the clavicle.
 A 22-gauge, 4-cm needle is inserted while
mimicking a plumb-bob suspended over the needle
entry site .
 Frequently, a paresthesia or motor response is
elicited before contacting the first rib or artery. If no
paresthesia or motor response is elicited, the needle
is redirected and reinserted.

60. In 1988 Brown described the plumb-bob technique

61. COMPLICATIONS:
 High incidence of
pneumothorax (0.5-6%)
 Horner’s syndrome
 Phrenic nerve block
 Neuropathy
 Its possible to get a good twitch and be superficial to the
sheath. Injection at this point will lead to block of the
superficial cervical plexus.

62. IS: one injection gets
full coverage, but
with phrenic nerve
dysfunction.
SC: doesn’t give
coverage of
shoulder, but can
avoid or reduce
phrenic nerve
dysfunction.

63. Ultrasound guided
Supraclavicular Brachial Plexus Block

64. POSITIONING
 The patient is placed supine
 The patient’s head is turned toward the
contralateral side
SONOANATOMY.
 The subclavian artery appears hypoechoic and pulsatile
and the individual nerves as hypoechoic small circles.
 It is very important to identify the pleura while performing
this block so as to avoid pneumothorax.

66. Supraclavicular Approach:
 Use in-plane approach only – so position of
needle relative to lung is always known.

67. In Plane
Medial
Lateral

68. INFRACLAVICULAR BLOCK

69. INFRACLAVICULAR BLOCK
Anatomy:
 In the infraclavicular area, the trunks divide into
anterior and posterior divisions each and then reform
into lateral, medial and posterior cords.
 The infraclavicular approach blocks the brachial
plexus at the level of the cords.
Clinical applications: provides homogenous
anaesthesia to the brachial plexus and can be used for
procedures involving arm, elbow, forearm and hand.
69

70. Technique: Infraclavicular technique places LA below
the clavicle on a line passing from the neck, under the
clavicle and into the axilla.
Classic approach- Patient lies supine with head
turned slightly towards the contralateral side. Operative
limb is abducted to 90 degrees and axillary pulse
identified.
70

71.  Midpoint of the clavicle is identified and a needle is
inserted 2 cm caudal to this point at an angle of 45
degrees towards axillary artery pulsation.
 A nerve stimulator is used to identify the plexus and
motor activity in the hand is sought.
 Once identified, the stimulation is decreased to <0.5
mA and fade of motor activity is witnessed after
injection of 1-2 ml of LA.
 Then after negative aspiration of blood, 30-40 ml of
LA is injected.
71

72. 72

73. Coracoid technique:
• With patient’s arm in any position, the coracoid process
is identified and marked.
• 2 cm medial and 2 cm caudal from the coracoid process,
the needle is inserted perpendicular to the skin till motor
response is achieved with the nerve stimulator.
73

74. 74

75.  Stimulation is decreased to <0.5 mA and after
injecting 1 ml of LA , fade in motor activity is
witnessed.
 Then 30-40 ml of LA is injected after negative
aspiration of blood.
75

76. Complications:
Pneumothorax, hemothorax and chylothorax may occur.
Its often prudent to avoid this approach in patients with
vascular catheters in subclavian region and in patients
with an ipsilateral pacemaker.
76

79. Axillary block

80. AXILLARY BLOCK
 The axillary brachial block was first described by Halstead in
1884.
Indication: Surgery on elbow, forearm & hand
Advantages:
a) Presence of a single landmark ( the axillary artery)
b) No possibility of pneumothorax, stellate ganglion block,
recurrent laryngeal nerve block, phrenic nerve block.
80

81.  Subclavian artery continues as the axillary artery in the
axilla i.e. beneath the clavicle.
 At the lateral border of pectoralis minor, the cords form
large terminal branches.
 The fascial sheath is multi-compartmental and these
fascial septa may result in incomplete spread of LA within
the plexus sheath leading to ‘patchy’ anaesthesia in many
patients.
81

82.  This approach tends to produce the most intense block
in the distribution of C7-T1 but is usually inadequate
for procedures on the shoulder and upper arm(C5-C6).
 Indicated for surgeries on elbow, forearm and hand.
 Unsuitable for surgeries on upper arm and shoulder.
82

83. Techniques:
 Axillary block is performed by one of the several
techniques that use the axillary arterial pulse as the
landmark.
 Patient positioning: The patient is placed supine with the
arm abducted, the elbow flexed at 90 degrees, and
externally rotated at the shoulder.
83

84. 84

85. 1) Transarterial technique:
 The pulse of the axillary artery is identified as proximal in
the axilla as possible.
 Once the artery is identified, it should be straddled
between the index and middle fingers and held tightly
against the humerus to prevent it from ‘rolling’.
 Then, a 22 G, 4 cm needle is inserted until bright red
blood is aspirated.
 The needle is then slightly advanced or withdrawn until
blood aspiration ceases.
85

86. 86

87. 87

88.  Injection can be performed anteriorly, posteriorly, or in
both locations in relation to the axillary artery. A total of
40 ml of LA is usually injected.
2) Elicitation of paraesthesia technique:
 With this technique, the needle is directed towards the
axillary artery to elicit a single or multiple paraesthesias.
88

89.  If the artery is entered, the needle is redirected until a
paraesthesia is obtained.
 Paraesthesia may be elicited in any area within brachial
plexus distribution or separately in ulnar, median and
radial nerve distribution.
 40 ml of the LA is injected.
89

90. 3) Nerve stimulator technique:
 For this technique, it is important to understand the
relationship of the three nerves to be blocked with the
axillary artery.
 The three terminal nerves usually lie in the following
positions relative to the artery: median nerve superior , the
ulnar nerve inferior, and radial nerve inferior- posterior.
90

91.  The axillary artery is ‘pinned’ in a stable position.
 Using a nerve stimulator, 22-G insulated stimulating
needle is inserted proximal to the operator’s fingers and
appropriate muscle twitches in the hand are elicited
 Greater success will be seen with multiple nerve
stimulations and divided doses of local anaesthetic.
91

92. ULTRASOUND TECHNIQUE
 Using high frequency linear array ultrasound transducer ,
the axillary artery and vein are visualised in cross section.
 The brachial plexus can be identified surrounding the
artery
 The needle is inserted superior to the transducer and under
direct visualisation local anaesthetic is then injected
around each nerve.

95. THERAPEUTIC INDICATIONS OF BRACHIAL
BLOCK –
 Inadvertent intra-arterial injections of Thiopentone.
 In cases of PVD of upper limb.
 For making A-V fistula in upper limb for dialysis.

96. THANK YOU