HEMATOMA BLOCK

Hematoma blocks can be used to prepare closed fractures for reduction and are an alternative when conscious sedation is contraindicated. Common fractures amenable to hematoma blocks include wrist and ankle fractures.

Technique

The fracture site is palpated to localize the fracture cavity with the fingertips. Using sterile technique, a needle is inserted into the fracture cavity and the hematoma is aspirated if possible to reduce tension on the periosteum and soft tissues. Anesthetic agent is then injected into and around the fracture cavity. Patients typically experience partial relief of pain with 5 to 10 minutes.

FEMORAL NERVE BLOCK

Distribution

Anterior thigh, periosteum of the femur, and knee

Anatomy

The femoral nerve runs in a sheath lateral to the femoral artery at the inguinal ligament. Anesthetic agent injected into the nerve sheath can travel along the nerve cranially and laterally to block femoral, obturator nerves, the lateral cutaneous nerve of the thigh, and the low cords of the lumba plexus.

Technique

The femoral neck block effectively anesthesizes femoral shaft fractures. This block has been shown to reduce the need for opioids, which can be advantageous in hemodynamically unstable trauma patients with femoral fractures (14, Tint). The landmark for this block is the femoral artery, which is palpable 1 cm below the inguinal ligament midway between the pubic symphisis and the anterior superior iliac crest. A long acting agent such as 0.25% or 0.5% bupivicaine is recommended to provide anesthesia for 3 to 8 hours. A typical adult dose is 10 ml to 20 ml. Using sterile technique, the needle is inserted 1 cm lateral to the femoral artery landmark while angled cephalad at a 60 degree angle. It is crucial to aspirate while advancing the needle to avoid intravascular injection of anesthetic agent. A slight “pop” may be felt as the needle enters the nerve sheath. If the patient experiences paresthesias the needle has entered the nerve itself and should be withdrawn slightly before the agent is infused. The thumb can be used to apply pressure to the nerve sheath distally to the injection site to encourage tracking of the anesthetic within the sheath in a cranial direction.

penile blocks

Indications

For laceration repairs, or dorsal slit procedures to correct phimosis.

Anatomy

The penis is innervated by the left and right dorsal nerves, both of which are branches of the pudendal nerves. They emerge from underneath the symphysis pubis bone. These nerves innervate the entire dorsal surface of the penis. The ventral penile surface and frenulum also have innervation by superficial nerves. For this reason, the ring block has been advocated over the dorsal nerve blocks.

Both procedures are described below.

Dorsal Penile Nerve Block:

Place the patient in a supine position.

Clean the skin with either a povidone – iodine or alcohol solution and allowed to dry.

Palpate the inferior aspect of the symphysis pubis bone and the base of the penis at 2 and 10 o’clock

To anesthetize the left dorsal penile nerve, insert a 27 gauge 3-4 cm length needle superior to the 2 o’clock site over the inferior portion of the symphysis pubis. Advance the needle until it reaches the bone, then walk the needle in a caudal fashion off of the pubis. There may be a popping sensation as the needle goes through the superficial fascia inferior to the pubis. At this site, inject 5cc of 1% lidocaine or 0.25% bupivacaine without epinephrine. Repeat the procedure in identical fashion at the 10 o’clock site to anesthetize the right dorsal penile nerve.

Subcutaneous Triangular or Ring Block:

Because the dorsal penile nerve block often fails to anesthetize the ventral aspect of the penis, the ring block has been advocated as the superior block for complete anesthesia of the penis.

Place the patient in the supine position and cleanse the skin as noted above. Using a 25- 27 gauge needle (3 inch long) should be used for the block. The two superior points of the triangle may be approximated by palpating the tubercles of the pubic bone and then marking a spots that are 2 cm inferior and medial to the tubercles. The inferior point of the triangle will be at the base of the penis, on the median raphe of the scrotum (the most superior and median aspect of the scrotum).

Using the needle, enter the skin at one of the superior triangular points and inject a subcutaneously, connecting the two superior points. Injecting in the intradermally is also useful to anesthetize superficial nerves.

Then withdraw the needle and place it at the base of the penis at the median raphe of the scrotum, and then inject both subcutaneously and intradermally while directing the needle toward 1 st the right superior end of the superior line, and then on the opposite side of the penis toward the left superior aspect superior border, completing the triangular block.

Alternatively, one can simply subcutaneously and intradermally infiltrate the base of the penis in a ring fashion, creating a true ring infiltration around the base.