Sciatic Block

Question 1

What nerve roots contribute to the sciatic nerve?

Answer 1

L4, L5, and S1-S3
Longnecker DE, Newman MF, Brown DL, Zapol WM.
Anesthesiology. 2nd ed. New York: McGraw-Hill; 2012: 843.

Question 2

What two nerves actually comprise the sciatic nerve?

Answer 2

The sciatic nerve is actually two nerves wrapped within the
same nerve sheath. The tibial portion is found more medial and
anterior and the common peroneal portion is lateral and
posterior within the sheath.
Longnecker DE, Newman MF, Brown DL, Zapol WM.
Anesthesiology. 2nd ed. New York: McGraw-Hill; 2012: 843-
844.

Question 3

What muscles are innervated by the sciatic nerve?

Answer 3

The sciatic nerve innervates the muscles of the back of the
thigh (biceps femoris, semitendinosis, semimembranosus, and
adductor magnus). As the sciatic nerve continues, it innervates
the muscles of the lower leg and foot.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 1122.

Question 4

What areas receive sensory innvervation from the

sciatic nerve?

Answer 4

Nearly all of the skin of the leg
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 1122.

Question 5

A sciatic block is sufficient for lower extremity
surgery not requiring a tourniquet if combined with
what other types of blocks?

Answer 5

The sciatic nerve may be combined with a lumbar plexus block,
femoral nerve block, or saphenous nerve block to provide
complete anesthesia for lower-extremity surgery.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 1121.