Transcript Slides 15 Ankle Block

Soli Deo Gloria
ANKLE BLOCK
Developing Countries Regional Anesthesia Lecture Series
Lecture 15
Daniel D. Moos CRNA, Ed.D.
U.S.A.
[email protected]
Disclaimer
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Every effort was made to ensure that material and
information contained in this presentation are
correct and up-to-date. The author can not accept
liability/responsibility from errors that may occur
from the use of this information. It is up to each
clinician to ensure that they provide safe anesthetic
care to their patients.
Introduction to the Ankle Block
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Common peripheral nerve block
Useful for procedures that do not require a
tourniquet above the ankle
Indicated for orthopedic and podiatry procedures
of the distal foot
Purely sensory block
Painful block
Conscious sedation….don’t over sedate!
The ankle block involves blockade of 5
peripheral nerves
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Posterior tibial nerve
Sural nerve
Superficial peroneal nerve
Deep peroneal nerve
Saphenous nerve
Anatomy
4 of the 5 nerves are terminal branches of
the sciatic nerve
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Deep peroneal nerve
Superficial peroneal nerve
Posterior tibial nerve
Sural nerve
The remaining nerve is the terminal branch
of femoral nerve
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Saphenous nerve
Deep Peroneal Nerve Anatomy
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Continues as an
extension of the common
peroneal nerve and
enters the ankle
between the flexor
hallucis longus tendons.
Deep Peroneal Nerve provides sensation to the
medial half of the dorsal foot (1st & 2nd digits)
Deep Peroneal Nerve can be located at the level of the
medial malleolus just lateral to the flexor hallucis longus
Medial
Malleolus
Extensor
Hallucis
Longus
Location of deep
peroneal nerve
Lateral
Malleolus
Extensor
Digitorum
Longus
Superficial Peroneal Nerve Anatomy
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Extension of the common peroneal nerve and enters
the ankle lateral to the extensor digitorum longus at
the level of the lateral malleolus
Superficial Peroneal Nerve
Superficial Peroneal Nerve provides sensation to
the dorsum of the foot as well as all five toes
Posterior Tibial Nerve Anatomy
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Extension of the tibial nerve and enters the foot
posterior to the medial malleolus, dividing into the
lateral and medial plantar nerves.
Posterior Tibial Nerve Anatomy
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Located behind the
posterior tibial nerve at
the level of the medial
malleolus
Posterior
Tibial
Nerve
Medial
Malleolus
Posterior Tibial Nerve provides sensation to the
heel, medial and lateral sole of the foot
Sural Nerve Anatomy
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Extension of the tibial
nerve and enters the
foot between the
Achilles tendon and
lateral malleolus
Sural Nerve Anatomy
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Located between the
Achilles tendon and
lateral malleolus
Lateral
Malleolus
Sural Nerve
Sural Nerve provides sensation to the
lateral foot
Saphenous Nerve Anatomy
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Terminal branch of the
femoral nerve located
anterior to the medial
malleolus
Saphenous Nerve Anatomy
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Provides sensation to the
anteromedial foot
Equipment
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Betadine and alcohol wipes
Sterile gloves
4x4 or 2x2’s
Sterile towels
2-3 10 cc syringes with local anesthetic
25 gauge needle 1.5 inch needle
Choice of Local Anesthetic
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Depends on the length of time you wish block to last
Longer acting local anesthetics may take longer for
onset
May wish to mix a local anesthetic that has faster
onset with a longer acting local anesthetic
Sodium bicarbonate may help speed onset
NEVER USE EPINEPHRINE!
Local Anesthetic Choices
Considerations
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Be careful with volume- tourniquet effect
Caution in patients with peripheral vascular disease
and diabetics
Care with patient with infection- risk of tracking
infection to healthy tissue and local anesthetic not
working due to acidotic tissue
Positioning the foot
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Position the foot so you
have access to all 5
nerves
Blockade of the Deep Peroneal Nerve, Superficial
Peroneal Nerve, and Saphenous Nerve can be blocked
in one needle stick.
Deep Peroneal Nerve Block
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Draw a line between the two malleoli
Identify the extensor hallucis longus tendon and the
extensor digitorum longus muscle
Palpate the anterior tibial artery
Deep Peroneal Nerve Block
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Place a skin wheal of local anesthetic lateral to the
artery
Advance the needle perpendicular, aspirating for
blood and deposit 3-5 ml of local anesthetic deep
to the extensor retinaculum
May choose to fan the injection in this area,
avoiding the artery
Deep Peroneal Nerve Block
Blocking the Superficial Peroneal
Nerve
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Bring the needle back and direct it superficially in a
lateral fashion towards the lateral malleolus
depositing 3-5 ml of local anesthetic subcutaneously
Blocking the superficial peroneal nerve
Blocking the saphenous nerve
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At the site of the deep peroneal nerve blockade
bring your needle back and redirect in a medial
direction towards the medial malleolus depositing
3-5 ml of local anesthetic
Blocking the posterior tibial nerve
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Warn your patient to hold still in case a paresthesia is elicited.
Movement at this time may result in trauma to the nerve.
Identify the posterior tibial artery at the level of the medial
malleolus and advance the needle in a posterolateral manner
slowly.
If a paresthesia is elicited withdraw the needle slightly and
inject 3-5 ml. Make sure the patient does not have pain as this
may imply an intraneural injection.
If no paresthesia is elicited than inject 7-10 ml as you
withdraw the needle. A paresthesia is not essential to a
successful block.
Blocking the posterior tibial nerve
Blocking the sural nerve
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Identify the lateral malleolus and the Achilles
tendon
Insert needle superficially lateral to the tendon and
in the direction of the lateral malleolus.
Inject 5-10 ml of local anesthetic subcutaneously as
you withdraw the needle
Blocking the sural nerve
Complications
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Discomfort to the patient
Injury to a “numb” foot after discharge
Nerve injury or paresthesia’s
Hematoma and vascular injury
Infection
Intravascular injection
Block failure
Conclusion
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Easy to administer
Effective anesthesia
Often performed with much less local anesthetic
than what textbooks advocate
Metatarsal Block
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A metatarsal block may supplement an ankle block
if a nerve distribution has been missed.
Never use epinephrine containing solutions. This can
result in ischemia of the digits.
Place a small skin wheal at the site of injection on
the dorsum of the foot.
Advance the needle while injecting local anesthetic
parallel to the metatarsal bone. Do not go through
the surface of the sole of the foot!
Metatarsal Block
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The individual nerves are located closer to the sole
of the foot than the dorsum.
A total of 3-5 ml of local anesthetic solution may be
deposited.
The same procedure should occur on the other side
of the metatarsal of the location that anesthesia is
desired.
Metatarsal Block
Metatarsals
References
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Burkard J, Lee Olson R., Vacchiano CA. Regional Anesthesia. In Nurse Anesthesia 3 rd edition. Nagelhout, JJ
& Zaglaniczny KL ed. Pages 977-1030.
Morgan, G.E. & Mikhail, M. (2006). Peripheral nerve blocks. In G.E. Morgan et al Clinical Anesthesiology,
4th edition. New York: Lange Medical Books.
Wedel, D.J. & Horlocker, T.T. Nerve blocks. In Miller’s Anesthesia 6 th edtion. Miller, RD ed. Pages 16851715. Elsevier, Philadelphia, Penn. 2005.
Wedel, D.J. & Horlocker, T.T. (2008). Peripheral nerve blocks. In D.E. Longnecker et al (eds) Anesthesiology.
New York: McGraw-Hill Medical.