Peripheral Upper Extremity Blocks (week 8) Flashcards
The brachial plexus originates from what 5 nerve roots?
- C5
- C6
- C7
- C8
- T1
Nagelhout, pg. 1149
As it courses distally, the 5 roots of the brachial plexus converge and diverge to form _______ trunks, _______ divisions, _______ cords, and ________ terminal branches
Randy Travis Drinks Cold Beer
- 3 (upper, middle, lower)
- 6 (3 anterior, 3 posterior)
- 3 (medial, posterior, lateral)
- 5 (axillary, radial, musculocutaneous, median, ulnar)
Nagelhout, pg. 1149
The supraclavicular portion of the brachial plexus includes the ___________ and is located in the _____________
- roots, trunks, divisions
- posterior triangle of the neck
Nagelhout, pg. 1149
The infraclavicular portion of the brachial plexus includes the __________ and is located in the ____________
- cords, branches
- axilla
Nagelhout, pg. 1149
The roots of the brachial plexus pass between which two muscles?
- Anterior scalene muscle and middle scalene muscle
Nagelhout, pg. 1149
At which anatomic location do the roots of the brachial plexus divide into the trunks?
- lateral border of the scalene muscles
Nagelhout, pg. 1149
Which spinal nerve roots form the following brachial plexus trunks?
Superior
Middle
Inferior
Superior trunk: formed by the C5 and C6 spinal nerves
Middle trunk: continuation of the C7 spinal nerve
Inferior trunk: formed by the C8 and T1 spinal nerves
Nagelhout, pg. 1149
At which anatomic location do the trunks of the brachial plexus divide into anterior and posterior divisions?
- Lateral border of the first rib
Nagelhout, pg. 1149
The anterior divisions of the brachial plexus generally supply the ________ areas of the upper extremity, while the posterior divisions supply the __________ regions of the upper extremity
- ventral (flexor)
- dorsal (extensor)
Nagelhout, pg. 1149
What divisions of the brachial plexus form the:
lateral cord
Posterior cord
Medial cord
- lateral = anterior divisions of the superior and middle trunks
- posterior = all 3 posterior divisions
- medial = anterior division of the inferior trunk
Nagelhout, pg. 1149
The cords of the brachial plexus are named according to their position in relation to ____________
- the axillary artery
Nagelhout, pg. 1149
At the lateral border of the ____________, the cords diverge into the five terminal branches that form the peripheral nerves of the upper extremity
- pectoralis minor muscle
Naglehout, pg. 1149
Which nerve is a continuation of the lateral cord?
- musculocutaneous
Nagelhout, pg. 1149
The median nerve arises from which cords?
- the lateral and medial
Nagelhout, pg. 1149
The _________ nerve extends from the medial cord
- ulnar
Nagelhout, pg. 1149
Which nerves arise from the posterior cord?
- radial
- axillary
Nagelhout, pg. 1149
Describe the motor and sensory innervation of the radial nerve
Roots C5-T1
- Motor: dorsal extensors of the upper limb below the shoulder
- Sensory: extensor region of the arm, forearm, and hand
Roots C5-T1
Nagelhout, pg. 1149-1150
Describe the motor and sensory innervation of the musculocutaneous nerve
Roots C5-C7
- Motor: flexor muscles of the ventral upper arm (biceps, brachialis, coracobrachialis)
- Sensory: lateral aspect of the forearm between the wrist and elbow (lateral antebrachial cutaneous nerve branch)
Nagelhout, pg. 1150
Describe the motor and sensory innervation of the median nerve
Roots C6-T1
- Motor: flexor and pronator muscles of the forearm
- Sensory: ventral portion of the thumb, 1st & 2nd fingers, 3rd finger (lateral half), palm of the hand
Nagelhout, pg. 1150
Describe the motor and sensory innervation of the ulnar nerve
Roots C8-T1
- Motor: small flexor muscles of the hand
- Sensory: 3rd finger (medial half), 4th finger, palm of the hand
Nagelhout, pg. 1150
Interscalene brachial plexus blocks are commonly performed for surgical procedures involving the ___________ and __________
- shoulder
- proximal upper arm
Nagelhout, pg. 1152
Interscalene blocks are not indicated for procedures below ________ as spinal nerve roots C8-T1 are often spared
- the level of the elbow
C8-T1 innervate parts of the forearm and hand
Nagelhout, pg. 1152
When utilizing ultrasound for an interscalene block, the trunks/divisions of the brachial plexus appear as a series of _________
- small HYPOechoic circles
“snowman” or “stoplight” sign
Nagelhout, pg. 1153 - Fig. 50.14
Which muscle does the needle pass through during an ultrasound guided interscalene block?
- middle scalene muscle
Dorsal scapular & long thoracic nerve often pass through here too - injury is possible
Nagelhout, pg. 1153
What structure lies close in proximity to the injection site during an interscalene block? What might occur if local anesthetic affects it?
- Phrenic nerve
- Unilateral phrenic nerve block/hemiparesis - NBD in healthy patients, but dangerous in those with severe pulmonary disease (COPD)
Nagelhout, pg. 1153
The stelate ganglion (located near C7) may also be affected during an interscalene block - this would result in _________ syndrome - symptoms include:
- Horner
- ptosis, miosis, anhydrosis
Nagelhout, pg. 1153
By what mechanism might an interscalene block cause hoarseness?
- Injection of large volumes of local anesthetics may cause unilateral recurrent laryngeal nerve paralysis
Nagelhout, pg. 1153
The supraclavicular block targets the ____________ of the brachial plexus
- trunks/divisions
Nagelhout, pg. 1153
Why is the supraclavicular block not the optimal approch for surgical procedures of the shoulder?
- The suprascapular nerve (which arises from the proximal upper trunk) is often missed
How should the patient be positioned for an ultrasound guided supraclavicular block?
- supine, with the head slightly elevated and turned to the nonoperative side
Nagelhout, pg. 1154
Because the trunks/divisions are typically less than ________ from the skin at the level of a supraclavicular block, a high-frequency, linear array is used
- 2 cm
Nagelhout, pg. 1154
During a supraclavicular block, the ultrasound transducer is placed in the midclavicular fossa, where the brachial plexus appears as a small cluster of ______echoic circles superior to the first rib
- hypo
Nagelhout, pg. 1154 - Fig 50.16
During a supraclavicular block, incremental injections of local anesthetic are deposited between the ___________ and ___________
- inferior border of the brachial plexus
- first rib
Nagelhout, pg. 1154 - Fig 50.16
The supraclavicular block is useful for which surgical procedures?
- Those involving the proximal upper arm, forearm, and hand
Nagelhout, pg. 1154
The greatest risk of the supraclavicular block is _________. This can be minimzed by positioning the transducer so that _________ is aligned under the nerves and over the _________
- pneumothorax
- first rib
- pleura
Nagelhout, pg. 1154-1155
The infraclavicular block targets the ___________ of the brachial plexus, medial to the coracoid process at the shoulder
- cords
Nagelhout, pg. 1155
Why is the infraclavicular approach a desirable alternative for upper extremity surgery in patients with severe respiratory compromise or COPD?
- reduced risk of phrenic nerve block
Nagelhout, pg. 1155
The infraclavicular block is the __________ painful of the brachial plexus approaches
- most - needle must pass through pectoralis major and minor muscles
Nagelhout, pg. 1155, 1156
True or false:
During an infraclavicular block the cords are located deeper in the tissue compared to the supraclavicular block, a higher frequency ultrasound transducer will need to be used
- False - a LOWER frequency transducer will be needed as they can image deeper structures
Nagelhout, pg. 1155
When performing an infraclavicular block, the nerves at this level appear _________echoic - this is most likely due to the increased amount of connective tissue surrounding the nerve fascicles
- hyper
Nagelhout, pg. 1155
The following is an ultrasound image obtained during an infraclavicular block - identify the cords of the brachial plexus (white circles/black dots)
- LC = lateral cord (cephelad to axillary artery)
- MC = medial cord (between axillary artery & vein)
- PC = posterior cord deep to the axillary artery)
Nagelhout, pg. 1155 - Fig. 50.17
The infraclavicular block is indicated for surgeries involving what anatomical structures?
- elbow
- forearm
- hand
Nagelhout, pg. 1155
The axillary block targets four terminal branches of the brachial plexus - what are they?
- radial
- median
- ulnar
- musculocutaneous
Nagelhout, pg. 1156
Of the 4 branches of the brachial plexus targeted with the axillary block, which are located around the axillary artery, and which nerve are located outside the axillary sheath?
- around the axillary artery: radial, median, ulnar
- outside the axillary sheath: musculocutaneous
Nagelhout, pg. 1156
The axillary block is indicated for what types of surgeries?
- surgeries of the elbow, forearm, and hand
Nagelhout, pg. 1157
What can be done to reduce tissue trauma when performing an axillary nerve block?
- slide the transducer proximal and distal to identify where all nerves are visualized in the same plan - allows for one needle insertion
Nagelhout, pg. 1157
Complications during an axillary block are not common - but ____________ appears to be the most concerning and frequent
- LAST
Nagelhout, pg. 1157
True or false:
Selective blocks at the elbow and wrist provide motor and sensory blockade
- False - they are primarily sensory blocks as the patient retains the ability to move the hand
Nagelhout, pg. 1157
The ulnar nerve is tightly fixed within the grove of the ulnar sulcus of the humerus - in order to reduce the risk of nerve entrapment anesthetic volumes greater than _________ should be avoided
- 3 mL
Nagelhout, pg. 1157
In order to perform an ulnar nerve block at the elbow, what position should the patients arm be in?
- Flexed 90 degrees
Nagelhout, pg. 1157
The median nerve block at the level of the elbow should be avoided in patients with _____________
- carpal tunnel syndrome
Nagelhout, pg. 1158
When performing a median nerve block at the level of the elbow, it is in close proximity to the ___________ artery - the needle should be inserted slightly ___________ to this
- brachial
- medial
Nagelhout, pg. 1158
When performing a selective radial nerve block at the elbow, the radial nerve can be located between the ____________ laterally and the ___________ medially
- brachioradialis muscle (fascial border)
- biceps tendon
Nagelhout, pg. 1158
When performing a selective radial nerve block at the elbow, the needle is directed toward the anterior aspect of __________ until gentle contact occurs - the needle is then slightly withdrawn and local anesthetic is injected
- lateral condyle of the humerus
Nagelhout, pg. 1158
When performing selective ulnar nerve blocks at the level of the wrist, what landmark structure needs to be identified? (the needle is inserted just laterally to it)
- ulnar flexor muscle (flexor carpi ulnaris muscle/tendon)
Nagelhout, pg. 1159 - Fig 50.22
You are performing a median nerve block at the level of the wrist - the needle should be inserted between the tendons of which two muscles?
- palmaris longus & flexor carpi radialis
Nagelhout, pg. 1159 - Fig 50.22
The radial nerve can also be blocked by identifying the ____________ muscle proximal to the wrist - this technique is the ___________ well tolerated of all the supplemental blocks
- brachioradialis
- least
also associated with limited success
Nagelhout, pg. 1159
Intravenous regional anesthesia (IVRA) is also known as the __________
- bier block
Nagelhout, pg. 1159
A bier block is best suited for what types of surgery?
- soft tissue surgeries of the upper extremity less than 1 hour in duration
Nagelhout, pg. 1159
Following passive exsanguination of the extremity, an ___________ bandage is tightly wrapped around the extremity starting at the ___________ end
- Esmarch
- distal
Nagelhout, pg. 1159
You are performing a bier block and have finished using the Esmarch bandage to achieve complete exsanguination of the extremity - what step follows this and precedes injection of local anesthetic?
- inflation of the proximal cuff
Nagelhout, pg. 1159
What is the only agent that appears to offer any significant clinical benefit when added to the local anesthetic during Bier block?
- Ketorolac 15-30 mg
Nagelhout, pg. 1159
During a bier block, tourniquet pain typically develops within __________. When this occurs, what can be done to help the patient tolerate the tourniquet for additional time?
- 20-30 minutes
- inflate the distal cuff and deflate the proximal cuff
A procedure for which you utilized a bier block only lasts 10 minutes - you know that the distal cuff must remain inflated for at least _________ in order to avoid ____________
- 20 mintues
- LAST
intermittent cuff deflation followed by inflation may be a good practice
Nagelhout, pg. 1160
Although rare, documented complications of IVRA include:
- neurologic injury
- compartment syndrome
- phantom pain
- limb amputation
Nagelhout, pg. 1160
Which nerve provides sensory innervation to #1
Axillary n.
Torabi’s PPT Slide 29
Which nerve provides sensory innervation to #2
Radial n.
Torabi’s PPT Slide 29
Which nerve provides sensory innervation to #3
Musculocutaneous n.
Torabi’s PPT Slide 29
Which nerve provides sensory innervation to #4
Radial n.
Torabi’s PPT Slide 29
Which nerve provides sensory innervation to #5
Median n.
Torabi’s PPT Slide 29
Which nerve provides sensory innervation to #6
Ulnar n.
Torabi’s PPT Slide 29
Which nerve provides sensory innervation to #7
Medial antebrachial cutaneous n.
Torabi’s PPT Slide 29
Which nerve provides sensory innervation to #8
Intercostobrachial n.
Torabi’s PPT Slide 29
Which roots innervate the Musculocutaneous n.?
C5, C6, & C7
Which roots innervate the Axillary n.?
C5, C6
Which roots innervate the Median n.?
C5-T1 (friggen all’em)
C6-T1 if you ask Nagelhout
Which roots innervate the Radial n.?
C5-T1 (All’em ‘gain)
Which roots innervate the Ulnar n.
C8 & T1
What pressure should you maintain an intraneural manometer?
<15 psi
Torabi’s PPT
What does a reading of > 15psi mean on an intraneural manometer?
Possibly intraneural placement
How much volume into the vertebral artery/Subarachnoid space does it take to induce a seizure?
1 mL
Nagelhout 7th ed., Ch 50., pg. 1153
You illicit a motor response with a nerve stimulator with a setting of 0.2mA, what are you concerned for?
The needle tip has penetrated the epineurium
(intraneural)
Nagelhout 7th ed., Ch 50., pg. 1145
What is the mA goal with a nerve stimulator to know you’re in the correct place?
0.3 - 0.5 mA
Nagelhout 7th ed., Ch 50., pg. 1145
What do you set the nerve stimulator to just after entering the skin?
1 mA
Nagelhout 7th ed., Ch 50., pg. 1171
You finish doing an interscalene block and your pt exhibits difficulty breathing. What steps do you take?
- Reassure them
- Rule out pneumothorax
- Listen for Breath sounds
- CXR
Our review
What can the phrenic nerve block contribute to?
25% reduction of Forced vital capacity
- especially in the R lung
UE/LE Block PPT Slide 41
Complications of an Infraclavicular block?
- Pain
- Chlyothorax w/ L-sided blocks
- LAST
- Pneumothorax
Nagelhout 7th ed., Ch 50., pg. 1156 & UE/LE Block PPT Slide 56
What kind of nerve blocks is Exparel use allowed?
- Interscalene
- Popliteal (Sciatic)
- Adductor Canal
UE/LE Block PPT Slide 33
What kind of field blocks is Exparel use approved for?
- TAP
- Rectus Sheath
- PECS I/II
- Erector Spinae
UE/LE Block PPT Slide 33
How much volume should be injected around each nerve in an Axillary block?
3-5mL ea. nerve
UE/LE Block PPT Slide 58
When would you choose an infraclavicular block over axillary?
The patient cannot abduct their arm
Which blocks can cause LAST?
All’em
Torabi
What LA do you use for a Bier Block?
- 50 mL of 0.5% Lidocaine(250 mg)
UE/LE Block PPT Slide 66
Your patient is experiencing sympoms of LAST, what do you give them?
Intralipids!
Pneumonic for LAST?
SAMS
- Slurred/difficult speech (numbness of lips/tongue)
- Altered CNS (restless, confused, drowsy, tinnitus)
- Muscle Twitching
- Seizures
UE/LE Block PPT Slide 99
