Upper blocks Flashcards
Advantages of regional anesthesia
- can avoid general anesthetic, cardiac or pulmonary disease, avoid opiates, pulmonary disease, induced sympathectory (reduced intraop blood loss), reduced N/V, preemptive analgesia (stop the pain pathway)
Describe the general characteristics of the brachial plexus
Interwoven network of nerves that innervates the pectoral girdle and upper limb, nerve roots in close proximity to each other with easily identifiable bony/vascular landmarks. multiple techniques for approach, supplies all motor to upper extremity, almost all sensory to upper extremity (except upper shoulder)
What are the terminal nerves and their origins
Musculocutaneous: C5, C6, C7 Axillary, C5, C6 Radial: C5, C6, C7, C8, T1 Median: C5, C6, C7, C8, T1 Ulnar: C8, T1
Describe the musculocutaneous nerve
C5-C7; exits the sheath high in the axilla, pierces the coracobrachialis. Motor to brachialis, biceps, coracobrachialis, flexes forearm.
Sensory to the lateral mid forearm up to the wrist
Axillary Nerve
C5, C6; leaves the plexus at the lower border of the pectoralis muslce
Motor: deltoid, teres minor
Senosry: inferior shoulder and upper lateral arm
Radial nerve
C6-T1
Motor: triceps, supinator, extensors of the forearm
Sensory: posterior arm and forearm, lateral border of elbow, thumb and dorsal surface of hand
Median nerve
C7-T1
Motor: flexors and pronator muscles of forearm, flexion of the wrist
Sensory: palmar surface of the hand, index, middle finger
Ulnar nerve
C8, T1
Motor: flexor carpi ulnaris; abducts fingers
Sensory: little finger, ring finger
Approaches to the brachial plexus
Interscalene, Supraclavicular, infraclavicular, axillary, terminal nerves
What is the inter scalene approach used for?
shoulder, clavicle, or upper arm surgery, proximal to elbow
provides anesthesia to upper branches of the brachial plexus and lower cervical plexus
spares the upper back
frequent ulnar sparing
What are the landmarks for the inter scalene approach?
posterior border of the SCM
groove between anterior and middle scaliness
at level of C6 (Cricoid cartilage)
Absolute and Relative contraindications for an inter scalene block?
Absolute: contralateral RLN palsy and phrenic nerve palsy
Relative: preexisting nerve injury, brachial plexus pathology, impaired pulmonary function.
Evaluation of an interscalene block?
Push- radial Pull- musculocutaneous Close- median Open- ulnar assess sensory to shoulder, posterior shoulder is often spared. Assess muscle tone is another way
Complications of the interscalene block
Intravascular injection, subarachnoid/epidural, pneumothorax, RLN block, Horners syndrome (droopy eyelids, ptosis, constricted pupils, lack of sweating), phrenic nerve block.
Weakness in respiratory effort
Cervical plexus block and landmarks?
for unilateral procedures of neck, combine with deep cervical plexus block for a carotid endartectomy
Landmarks: posterior border of SCM,
Indications for a supraclavicular approach?
Effective for all portions of upper extremity: hand, forearm, upper arm
Trunks/divisions level
Increased success of blocking the inferior trunk of ulnar and radial nerves
(interscalene is roots/trunks)
Contraindications: contralateral phrenic and RLN, pneumo (higher risk of pneumo)
Supraclavicular approach landmarks
Lateral border of the clavicular head of the SCM, identify the groove between the scalene muscles, inject caudal at the clavicular level
Should see a twitch of the hand or arm at 2-3 cm, the more distal the twitch, the more reliable!
If motor response is maintained at 0.5 mAmp or less, inject. aspirating q5 mL.
Complications of supraclavicular approach:
Increased risk of pneumothorax 1-6% Horners syndrome Phrenic nerve block RLN paralysis Neuropathy (nerve pinned against clavicle)
Infraclavicular indications/landmarks
elbow, forearm, hand
Medial clavicular head and coracoid process
direct needle at midpoint in a parallel fashion, look for pectorals twitch (too shallow), want median, ulnar, radial twitch at 5-8cm.
*good for continuous catheters
needle directed laterally neuraxial or pulmonary complications unlikely
Missing MUSCULOCUTANEOUS!
Axillary block indications/contraindications
BELOW THE ELBOW (safest and easiest approach) pt must be able to abduct 90; supine, palpate the axillary artery as proximally as possible
Absolute: lymphangitis
Relative: preexisting nerve injury, brachial plexus pathology
Median: superior to axillary artery
Ulnar: inferior to axillary
Radial: posterior to axillary
Approaches: nerve stimulator, transarterial, paresthesia
How do you evaluate the effectiveness of the axillary block?
“Push”- radial nerve
*“Pull”- musculocutaneous nerve usually spared and requires injection into belly of coracobrachialis
“close” - median
“Open” - ulnar
What are complications of an axillary block?
Hematoma, intravascular injection, infection
Touch up nerve blocks and landmarks?
Radial: brachioradialis muscle and tendon of biceps, insert lateral to biceps tendon (fan)
Median: 1 cm lateral to brachial artery
Ulnar: proximal to the ulnar groove
Musculocutaneous: deep in the body of the coracobrachialis
