Upper Extremity Nerve Blocks Flashcards
What are the five components that make up the brachial plexus anatomy?
Roots –> Trunks –> Divisions –> Cords –> Nerves
Where are the roots in the brachial plexus?
They come off of the spinal cord itself
What are the three components of the trunks?
Superior
Middle
Inferior
Where are the division in the brachial plexus?
Divisions are underneath the clavicles
What nerve supplies motor and sensory to the scapula in the back of the arm?
Suprascapular nerve (exits C5-6)
What are the three components of the cords?
Lateral, posterior and medial
What three nerves are enveloped in the brachial fascia?
Median nerve
Radial nerve
Ulnar nerve
What nerve roots are encompassed in the median nerve?
C5, 6, 7,8 and T1
What nerve roots are encompassed in the radial nerve?
C5, 6, 7, 8 T1
What nerve roots are encompassed in the ulnar nerve?
C7, 8 T1
What nerve supplies a large portion of the distal arm?
Musculocutaneous nerve
Where is the brachial plexus located?
Runs off the neck between the anterior and middle scalene muscles
What is the importance of the sternocleidomastoid muscle?
Point of clavicular attachment
What structure emerges and crosses the scalene muscle?
The phrenic nerve (bilateral)
What is the primary function of the phrenic nerve?
Primarily motor to diaphragm but does have sensory, can have dull achy pain if hit by needle
What can occur if LA is injected too close to the phrenic nerve?
Blocks nerve conduction resulting in a hemidiaphragm
Where can LA be injected to anesthetize all three nerves of the brachial plexus?
Fascial tube
What muscle does the musculocutaneous nerve innervate?
The corticobrachialis muscle
What part of the hand does the median nerve supply?
Part of the thumb, the index and middle finger and have of the ring finer
What part of the hand does the radial nerve supply?
Supplies the part of the thumb, up the arm and parts of the index and middle finger
What part of the hand does the ulnar nerve supply?
Supplies pinky side of the ring finger and the pinky finger
If the surgeon is operating on the ring finger what two nerves need to be blocked?
The median and the ulnar nerve
If the surgeon is operating on the thumb what two nerves need to be blocked?
The median and radial nerve
What are the three approaches to a brachial plexus block?
Axillary
Interscalene
Supraclavicular
What is the most common approach to a brachial plexus block?
Axillary Approach due to minimal number of complications
What surgeries is a brachial plexus indicated?
Surgery below the elbow and hand, good for surgeries on forearm and wrist
How must the arms be positioned to perform an axillary approach to a brachial plexus block?
Arm must be abducted
If a tourniquet is going to be used and a brachial plexus block is planned what additional nerves will need to be blocked?
Intercostobrachial and Medial cutaneous nerves must be blocked separately
Why is it important to make sure that the arm is not abducted greater than 90 degrees in an axillary approach to a brachial plexus block?
If it is abducted greater than 90 degrees the head of the humerus pinches off the fascial sheath and prevents the spread of LA
What is the landmark in an axillary approach to a brachial plexus block?
Palpate the axillary artery, straddle between the index and middle finger and inject skin wheel tangential across artery