Well tolerarted Familarity of fem triangle Infrquent complications
Ultrasound Guided Peripheral Nerve Blocks
Femoral nerve block
The femoral nerve
anesthesia for the
entire anterior thigh,
the knee, and the
In addition, skin
anesthesia is conferred
over the medial
aspect of the distal
lower extremity via the
terminal branches of
the femoral nerve.
The lumbar plexus gives rise to the femoral
nerve (L2 – L4).
The femoral nerve enters the thigh passing
under the inguinal ligament, located lateral
to the femoral artery surrounded by the fascia
iliaca which separates it from the femoral
artery and vein.
Distal to the inguinal ligament, the femoral
nerve splits into the anterior branch, providing
skin sensation, and the posterior branches,
supplying the quadriceps muscle, medial
knee and skin sensation to the medial calf.
Why use a probe?
Ultrasound application allows
monitor the spread of local anesthetic and needle
placement and make appropriate adjustments,
should the initial spread be deemed inadequate.
because of the proximity to the femoral artery,
ultrasound may reduce the risk of arterial puncture
that often occurs with this block with the use of nonultrasound techniques.
Palpating the femoral pulse as a landmark for the
block is not required with ultrasound guidance, a
process that can be challenging in obese patients.
A high frequency (6 – 18 MHz) linear array
A curvilinear probe can be used if more depth is
The probe is placed in the inguinal crease, in
The probe is slid until the femoral vessels are seen.
The nerve lies about 1-2 cm lateral to the artery,
positioned below fascia iliaca and lata and
above the ilieopsoas muscle
The nerve itself can have a triangular or oval
shape and is often not clearly visualized. Because
of this, the triangle created by the femoral artery
medially, fascial planes anteriorly and the iliopsoas
muscle posteriorly is used as the target for the
block. The nerve becomes visualized after
goal is to place the needle tip
immediately adjacent to the lateral
aspect of the femoral nerve, into the
wedge-shaped tissue space lateral to the
Proper deposition of local anesthetic is
confirmed by observation of the femoral
nerve being lifted off of the surface of the
iliopsoas or of the spread of the local
anesthetic above in the wedged-shaped
space lateral to the artery.
Median nerve block
toward the wrist deep to
the flexor digitorum
superficialis in the center
of the forearm.
superficial position until it
is located beneath the
flexor retinaculum in the
carpal tunnel with the
tendons of flexor
superficialis, and flexor
MN-at the elbow
In the antecubital fossa, the
median nerve lies medial to
the brachial artery.
With the arm extended, a
high-frequency (8-18 MHz)
probe is placed tranversely
over the brachial artery
Medial to the artery, the
median nerve is exhibits its
are five nerves that provide sensory
innervation to the foot at or below the
level of the ankle. These are four distal
branches of the sciatic nerve (posterior
tibial, sural, deep and superficial peroneal
nerves) and one branch from the femoral
nerve (saphenous nerve).