Intercostal Nerve Block

Question 1

What are the indications for performing an intercostal

nerve block?

Answer 1

Intercostal nerve blocks are not typically performed as the sole
anesthetic for surgical procedures, but are instead used for
postoperative pain management for thoracic or upper
abdominal procedures or for pain due to shingles, cancer, or rib
fractures.
Butterworth JF, Mackey DC, Wasnick JD. Morgan & Mikhail’s
Clinical Anesthesiology. 5th ed. New York, NY: McGraw-Hill;
2013: 1018.

Question 2

How is an intercostal nerve block performed?

Answer 2

The patient is positioned in the supine or lateral decubitus
position. The correct rib is identified by palpation and then a 22
or 25 gauge needle is walked off the inferior border of the rib
and advanced about 0.5 cm. After careful aspiration for blood
or air, 3 to 5 mL of local anesthetic is injected.
Butterworth JF, Mackey DC, Wasnick JD. Morgan & Mikhail’s
Clinical Anesthesiology. 5th ed. New York, NY: McGraw-Hill;
2013: 1018.

Question 3

What are the risks of intercostal nerve block?

Answer 3

Because of the proximity of the nerve to the vascular structures
in the intercostal neurovascular bundle, intravascular injection is
a risk. Because of the proximity of the needle tip to the pleura,
it is possible to cause a pneumothorax. Also, an intercostal
injection results in the highest blood levels of local anesthetic
per volume injected for block of a specific nerve, so drug toxicity
is a potential risk if large amounts of local anesthetic are
injected.
Butterworth JF, Mackey DC, Wasnick JD. Morgan & Mikhail’s
Clinical Anesthesiology. 5th ed. New York, NY: McGraw-Hill;
2013: 1018.

Question 4

How are the structures of the intercostal

neurovascular bundle positioned?

Answer 4

The intercostal neurovascular bundle travels underneath the
rib. From superior to inferior lie the vein, artery, and nerve.
Butterworth JF, Mackey DC, Wasnick JD. Morgan & Mikhail’s
Clinical Anesthesiology. 5th ed. New York, NY: McGraw-Hill;
2013: 1018.

Question 5

From where do the intercostal nerves originate?

Answer 5

The intercostal nerves originate from the dorsal and ventral rami
of the thoracic spinal nerves.
Butterworth JF, Mackey DC, Wasnick JD. Morgan & Mikhail’s
Clinical Anesthesiology. 5th ed. New York, NY: McGraw-Hill;
2013: 1018.

Question 6

Along what path do the intercostal nerves travel?

Answer 6

After originating from the thoracic spinal nerves, the intercostal
nerves exit at the intervertebral foramina and travel along the
underside of the rib.
Butterworth JF, Mackey DC, Wasnick JD. Morgan & Mikhail’s
Clinical Anesthesiology. 5th ed. New York, NY: McGraw-Hill;
2013: 1018.