With the rapid development of the industries and introduction of the high speed machineries, there is a steep increase in the number of industrial accidents; to add to this the automobile accidents (road traffic accidents) and increasing violence contribute to the further increase in the trauma to the hand. Specialized departments of hand surgery are being introduced in many hospitals. Regional blocks especially the brachial plexus block has revolutionized the management of hand injuries in that the patients can be taken immediately for surgery without fear of 'full stomach' as in general anesthesia.  Further the role of the anesthesiologist is not over by providing analgesia intra operatively but also extends well into the postoperative period. This is accomplished by brachial plexus block.

Anatomy

The brachial plexus is formed by the union of the Anterior Promary Rami of C5, C6, C7, C8 and T1 spinal nerves. The C5 receives a thick twig from C4 and T1 receives a slender twig from T2. Clinically the Brachial Plexus is divided into the Supra Clavicular Part ( In the Posterior Triangle of the neck ) and an Infra Clavicular Part ( In the Axilla ).
 

1 - The Five roots and
2 - Three trunk lying outside the inter vertebral foramia between the scalenus anterior and medium muscles.

a. Long thoracic nerve ( Serratus Anterior )
b. Dorsal scapular nerve ( Rhomboids )
c. Twig to the phrenic nerve

Here the roots of C5 and C6 form the upper trunk ( Capital Letus ), the root of C7 continues as the middle trunk and the roots of C8 and T1 form the lower trunk. The supra clavicular nerve to Supra Spinatus and Infra Spinatus muscles. This point is called the ‘ ERB’s Point ’. The Pre Vertebral fascia provides a sheath to cover the trunks continuing into the Axilla as the ‘Axillary Sheath’.

The three trunks divide into the Anterior and the Posterior Divisions, which unites to form the three cords, which enter the axilla through its apex.

* Lateral Cord: formed by the anterior divisions of upper and the middle trunks
* Medial Cord: continuation of the anterior division of the lower trunk
* Posterior Cord: formed by the posterior divisions of the upper, middle and the lower trunks
 

The 3 cords and their main branches are related to axillary artery as follows:

First Part       : The medial cord lies posterior to the artery.  The posterior
                         cord is postero lateral and the lateral cord is anterolateral

Second Part  : The medial, posterior and lateral cords are related by the
                         manner indicated in their names
 

Lateral Cord Gives Off

a.  Lateral pectoral nerve                       - Pectoralis major Biceps Brachii

b.  Musculo cutaneous nerve                 - Brachialis
     (Continues as lateral
     Cutaneous nerve of forearm)            - Coracobrachialis

c. Lateral root of median nerve
 

Medial Cord Gives Off

a. Medial Pectoral nerve
- Pectoralis major and minor muscles

b. Medial Cutaneous nerve of arm

c. Medial Cutaneous nerve of forearm

d. A contribution to Inter Costobrachial nerve
(Formed by the union of twigs from the second inter-costal nerve and the medial cutaneous nerve of the arm)

e. Ulnar nerve
- Flexor carpi ulnaris
- Medial part of flexor digitorum profundus
- Hypothenar muscles
- Interossei
- Adductor pollicis
- Medial 2 lumbricals
- Cutaneous branches

f. The medial root of median nerve
 

Posterior Cord Gives Off

a. Upper Sub Scapular nerve ( Supra Scapularis muscle )
b. Lower Sub Scapular nerve ( Supra Scapularis and Teres Major muscles )
c. Thoraco - Dorsal nerve ( Lattismus Dorsi )
d. Axillary nerve ( Deltoid and Teres Minor )
e. Radial nerve ( Biceps Brachii, Anconeus and the Extensor muscles of forearm besides the Cutaneous Branches)

Though there are many techniques, the commonly employed ones are

1. Inter scalene
2. Supra clavicular
3. Axillary

Other Techniques Are

4. Para Scalene
5. Sub Clavian Peri Vascular
6. Infra Clavicular
 

Inter scalene Approach

The patient lying Supine with the head resting on a pillow and turned slightly to the opposite side. the posterior border of Sternomastoid is identified. in case of difficulty, ask the patient to raise the head off the pillow as this tenses the muscle.

Landmarks

1. Cricoid cartilage
2. Posterior border of Sternomastoid muscle
3. Chessaignac’s Tubercle – Transverse process of C6
4. Mid point of the Clavicle

The Chassaignac’s tubercle is located either by palpation or by drawing a transverse line from the Cricoid Cartilage to the Posterior border of Sternomastoid muscle. A vertical line is drawn from the Mid Clavicular point. The meeting point of the two lines is the needle point.

Technique

The skin is prepared under strict aseptic precautions with antiseptic lotion. After raising wheal at the point of entry of the needle, the needle is advanced at 90 degree to the skin and advanced medially and caudally. Then finally Posteriorly until Paraesthesia is elicited in the upper limb. Local anaesthetic solution is then injected after negative aspiration while giving proximal compression above the needle to prevent Cephalic spread of the solution and also to limit the volume of the solution required.

It is important to stress that the plexus is rarely more than 2.5 cm from the skin. By careful aspiration and accurate placement of the needle in the peri neural sheath, the accidental Intra Vascular or Intra Dural or Extra Dural injection is avoided.

Complications

1. Injury to the vertebral artery
2. Hoarseness of voice
3. Stellate ganglion block
4. Accidental intra or extra dural injection

Indications

1. All the surgeries in the upper limb including the shoulder area
2. Used in rheumatoid arthritis
3. Used in neoplasms of the upper limb for ablation of the plexus
4. Used in the chronic intractable pain

Advantages

a. Simpler, safer and easier to perform
b. Economical and cost effective
c. Full stomach problems of general anaesthesia is absent
d. No theatre pollution
e. Can be used for continuous postoperative pain relief using an Intra Cath
f. Pneumothorax avoided
 

Supra Clavicular Approach

Position Of The Patient

* Patient lies supine with the head resting on a pillow
* Head turned slightly to the opposite side
* Arm by the patient’s side
* Lateral border of sternomastoid identified

Needle Used

a. Short bevel needles preferable as the penetration of the sheath is readily appreciated and the incidence of injury to the nerve is also decreased
b. Immobile needle technique (Winnie 1969) is used in which an extension set connects the needle to the syringe. The set is primed with fluid to avoid air embolism and allows the needle to be held motionless during aspiration, injection and changing the syringe

Techniques

1. After a thorough aseptic preparation of the skin and draping with sterile towels, the landmarks are palpated
2. Skin infiltrated with local anesthetic solution 1 cm above and immediately lateral to the mid point of the clavicle
3. A 5 cm long fine gauge needle is inserted at an angle of about 80 degree to the skin
4. The needle is directed backward, inward and downward to the upper surface of the first rib over which the plexus runs
5. It is helpful to push Sub Clavian artery medially with first 2 fingers of other hand to avoid the risk of any arterial puncture
6. A 30 ml mixture of 1 % lignocaine or 00.25 % Bupi Vacaine with adrenaline is injected after eliciting paraesthesia and negative aspiration
7. Use of cannula facilitates continuous block

Indications

1. Causalgia and other reflex Sympathetic Dystrophy
2. Phantom pain or post amputation pain in the stump
3. To differentiate pain of peripheral neuralgia from that caused by disorders of central nervous system
4. Effective in confirming the results of Cervico Thoracic sympathetic block in the management of patients with Causalgia or other reflex symphathetic Dystrophies or those with painful vascular disorders since all the sympathic fibres destined for the limb are carried by the Plexus
5. Temporary relief from trauma pain, post operative pain or that due to Arterial Spasm due to Intra Arterial Thiopentone injection or pain due to an Embolus

Contra Indications

1. Children – Relative Contra indications. Axillary approach is advisable
2. Tall, narrow chested patients – apex of pleura at higher level

Complications

1. Haematoma
2. Pneumothorax
3. Toxicity of local anaesthetic
4. Arterial puncture
 

Axillary Approach

Position Of The Patient

1. Patient lies supine with head resting on the pillow.
2. The arm is abducted at 90 degree and externally rotated.
3. The forearm is flexed 45 degree at the elbow.
4. The axillary area is scrubbed with antiseptics.
5. Axillary artery identified by palpation.
6. Skin wheal with local anaesthetic is made.
7. A 23 g, 5 cm needle is inserted, perpendicular to the skin at 30 degree and parallel to the artery
8. Application of a Tourniquet may facilitate the Cephalic spread of the solution and also to reduce the volume of the local anaesthetic used.

9. A 10 - 15 ml local anaesthetic solution is injected on either side of the artery after penetration of the fascial sheath and negative aspiration.

or

The needle is advanced to the side of the artery until a definite and sudden give or click is experienced. A finger is placed distal to the needle during the injection and this distal pressure should be maintained for at least 10 minutes

10.   The axillary sheath is effectively filled by 40 ml of 1 % lignocaine with Adrenaline.
11.  Continuous injection will be possible if a cannula is introduced into the sheath.
 

Alternate method

1. A deliberate puncture of the axillary artery is made with a 25 G needle
2. Once artery is punctured, needle is advanced slowly while aspiration is continued
3. As soon as the blood can be aspired no longer, ( indicating that the needle tip has passed through the artery and is situated posteriorly within the sheath ) , the needle is fixed and the injection made. Advocates of this technique claim that it is more likely to produce block of the radial nerve distribution

Dosage

1. Well developed male (70 kgs.) – 20 to 30 ml of 1 % lignocaine with 1 in 200,000 adrenaline
2. Smaller males and females (50 - 70 kgs.) – 20 to 25 ml of 1 % lignocaine with adrenaline
3. Teenagers (40 – 60 kgs.) – 15 to 20 ml lignocaine with adrenaline
4. Children 8 –12 years (25 – 35 kgs.) 14 to 20 ml lignocaine with adrenaline
5. Children 4 to 7 years (19 – 25 kgs.) 9 to 14 ml lignocaine with adrenaline
6. Children 1 to 3 years (8 – 10 kgs.) 6 to 9 ml lignocaine without adrenaline

Indications

1. Operations on hand, forearms and distal part of upper arm
2.  Reduction of fractures in small children

Contra Indications

1. Damage or disease of the plexus or the distal nerves of the arm

Complications

1. Arterial puncture
2. Vein puncture
3. Haematoma

Merits

1. Easiest and simplest method
2. No risk of pneumothorax