Brachial Plexus Block Flashcards
How do you anesthetize the musculocutaneous
nerve?
By injecting 3-5 mL of local anesthetic into the coracobrachialis
muscle.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 1112.
Which nerve roots form the superior, middle, and
inferior trunks of the brachial plexus?
The C5 and C6 nerve roots form the superior trunk, C7 forms
the middle trunk, and C8 and T1 form the inferior trunk.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 1108.
What nerve roots contribute to the radial nerve?
C5 to T1
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 1108.
What nerve roots contribute to the ulnar nerve?
C8-T1
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 1108.
Which nerve roots contribute to the median nerve?
C6-T1
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 1108
For what procedures is an axillary brachial plexus
block best suited?
An axillary brachial plexus block is best suited for procedures at
or below the elbow.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 1111.
The brachial plexus is formed from the rami of which
nerves?
It is formed from the rami of C5-T1.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 1108.
What three nerves may need to be blocked
separately to augment an axillary block?
The musculocutaneous, medial brachial cutaneous, and
intercostobrachial nerves may need to be blocked separately as
they exit the brachial plexus sheath high in the axilla.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 1112.
How does an interscalene brachial plexus block
affect respiratory function and why?
An interscalene brachial plexus block with 40-50 mL of local
anesthetic ensures a nearly 100% incidence of ipsilateral
hemidiaphragmatic paresis. Reducing the volume of local
anesthetic to 30 mL, however, does not reduce the incidence of
paresis and its pulmonary effects significantly. The paresis is
typically complete within 15 minutes of injection and normal
hemidiaphragmatic motion typically returns in about 3-4 hours.
Yao FF. Anesthesiology: Problem-Oriented Patient
Management. 7th ed. Philadelphia: Lippincott, Williams, and
Wilkins; 2012: 1035.
For what procedures is an interscalene brachial
plexus block sufficient?
A brachial plexus block is usually indicated for procedures on
the shoulder, upper arm and forearm. It is usually not sufficient
for procedures on the hand, however. The C8 and T1 nerves
which innervate the ulnar aspect of the forearm are frequently
missed as well.
Barash PG, Cullen BF, Stoelting RK, Cahalan MK, Stock MC,
Ortega R. Clinical Anesthesia. 7th ed. Philadelphia, PA:
Lippincott Williams and Wilkins; 2013: 959.
The presence of cough or chest pain while
performing a supraclavicular, infraclavicular, or
interscalene brachial plexus block may indicate
what?
Chest pain or cough during the procedure can be an indication
of an inadvertant pneumothorax.
Barash PG, Cullen BF, Stoelting RK, Cahalan MK, Stock MC,
Ortega R. Clinical Anesthesia. 7th ed. Philadelphia, PA:
Lippincott Williams and Wilkins; 2013: 961.
What are the most serious potential complications of
an interscalene brachial plexus block?
Vertebral artery injection, high epidural or spinal anesthesia,
and pneumothorax.
Barash PG, Cullen BF, Stoelting RK, Cahalan MK, Stock MC,
Ortega R. Clinical Anesthesia. 7th ed. Philadelphia, PA:
Lippincott Williams and Wilkins; 2013: 961.
What is Horner’s syndrome and how does it relate to
interscalene brachial plexus blocks? What other
nerves are often blocked incidentally when
performing an interscalene block?
Horner’s syndrome occurs as a result of incidental blockade of
the stellate ganglion and causes anhidrosis, myosis, and
ptosis. Incidental blockade of the phrenic nerve will result in
ipsilateral hemidiaphragmatic paralysis, which can be significant
in patients with severe respiratory problems. Incidental
blockade of the recurrent laryngeal nerve will result in
hoarseness from unilateral paralysis of the vocal cord.
Butterworth JF, Mackey DC, Wasnick JD. Morgan & Mikhail’s
Clinical Anesthesiology. 5th ed. New York, NY: McGraw-Hill;
2013: 988.
What are the major potential complications of a
supraclavicular brachial plexus block?
Pneumothorax, hemothorax, and chylothorax are potential
complications of a supraclavicular brachial plexus block.
Butterworth JF, Mackey DC, Wasnick JD. Morgan & Mikhail’s
Clinical Anesthesiology. 5th ed. New York, NY: McGraw-Hill;
2013: 988.
How is a supraclavicular brachial plexus block
performed?
Just posterior to the subclavian artery between the clavicle and
the first rib, the brachial plexus is tightly compacted. Because
of this, a block performed here will achieve adequate
anesthesia of the entire arm and hand. The patient is
positioned supine with the head turned to the opposite side. A
skin wheal is raised posterior to the subclavian artery at the
most inferior point of the interscalene groove. A 22-gauge, 1.5
inch needle enters the wheal posterior to the pulse and is
directed caudally until a paresthesia or muscle contraction (if
using a nerve stimulator) is elicited. If blood is aspirated,
redirect the needle posteriorly and laterally. If the first rib is
encountered, walk the needle in an anterior to posterior manner.
Butterworth JF, Mackey DC, Wasnick JD. Morgan & Mikhail’s
Clinical Anesthesiology. 5th ed. New York, NY: McGraw-Hill;
2013: 986-988.
