Chapter 46- Nerve blocks of the lower extremity

Question 1

What is multiple myeloma

Answer 1

proliferation of malignant plasma cells and overabundcane of monoclonal paraproteins that accumulate in places like bone marrow- inhibits formation of normal hematopoetic cell, kidneys, heart

Question 2

What are concerns related to multiple myeloma?

Answer 2

Bone pain from bone metastasis and pathologic fractures, spinal cord compression, renal dysfunction, hypercalcemia, anemia and abnormal bleeding from thrombocytopenia, and immunodeficiency

Question 3

For an ankle block, which 5 nerves need to be covered and what are the landmarks for an ankle block?

Answer 3

Sciatic nerve contribution- deep peroneal, superficial peroneal, tibial and sural and saphenous which is femoral nerve contribution.

The 2 major nerves providing motor function need to be specifically blocked (posterior tibial and deep peroneal) and sensory nerves are blocked by common subcutaneous ring.

Posterior tibial nerve- needle inserted at the level of the medial malleous and advanced until get posterior tibia and 5-8 mL of local anesthetic WITHOUT epi is injected just suerficial to the periostium.

The deep peroneal nerve lies deep between the tendons of the tibialis anterior and extensor hallus longus and 3-5 mL of LA are injected here.

Question 4

What are major disadvantages to the ankle block

Answer 4

discomfort in getting block, especially as there are multiple needle injections, motor is not blocked and patients have to be reminded to not move their feet and inability to use tourniquet

Question 5

What are advantages of the ankle block

Answer 5

superficial and safety profile

Question 6

If performing a toe surgery, other than ankle block, what other regional techniques could be used?

Answer 6

Beer blocks; sciatic nerve and saphenous nerve blocks combined

Question 7

Where on the knee can the saphenous nerve be blocked?

Answer 7

in the Hunter’s canal-

Question 8

What are the landmarks for doing a intertendinous sciatic nerve block?

Answer 8

Looking for popliteal triangle-

1) laterally- biceps femoris tendon
2) medially- semitendinous and semimembranous tendons
3) inferiorally- popliteal crease

Insert needle 7 cm above popliteal crease at midpoint between the tendons

Question 9

What are advantages to using ultrasound guidance for peripheral nerve blocks?

Answer 9

Interpatient variability for landmark guidance.
Electrical stimulation or parastesia guidance can show you where the nerve is, but once injection has begun, you do not know if the needle tip has moved.