Overview
- 1.
A hematoma block may be performed anywhere an acute fracture is present.
- 2.
Typically, hematoma blocks are performed in regions where it is impractical to perform selective nerve blocks or regional blocks.
- 3.
Hematoma blocks function on the principle that a fracture hematoma surrounds a fracture site.
- a.
The fracture hematoma acts as a fluid medium; thus, injection of an anesthetic into the hematoma results in diffusion of the anesthetic around the fracture site.
- b.
Diffusion of the anesthetic around the fracture site results in effective regional anesthesia.
- a.
Indications for Use
- 1.
Hematoma blocks are most commonly used for closed reduction of a distal radius fracture.
- 2.
Any diaphyseal or metaphyseal fracture is amenable to a hematoma block.
Precautions
- 1.
Hematoma blocks should not be used in patients with broken or tenuous skin overlying the fracture site.
- 2.
Hematoma blocks are typically ineffective in open fractures.
Pearls
- 1.
A combination of lidocaine and bupivacaine is used to provide both immediate and lasting analgesia. Use of bupivacaine is not mandatory, but fracture reductions are painful, and the use of a long-acting analgesic facilitates recovery in the postreduction period.
- 2.
The injection site can be reasonably approximated with use of palpation and radiographs. Because the periosteum is extremely sensitive, the practice of “walking” the needle down the bone until the fracture site is reached should be avoided.
- 3.
Most patients present for treatment several hours after the initial injury has occurred and the fracture hematoma has started to organize. Thus, most fracture hematomas cannot be aspirated, and typically no flashback of hematoma is seen in the syringe.
- 4.
A hematoma block typically requires 5–10 min to become fully effective.
Equipment
- 1.
Antiseptic: A chlorhexidine prep stick or alcohol-soaked gauze
- 2.
Syringe: A 10-mL syringe
- 3.
Needles:
- a.
A large-bore, blunt-tipped drawing-up needle
- b.
A 1-in., 22-gauge needle
- a.
- 4.
Anesthetics (for a typical adult):
- a.
Lidocaine: 5 mL of 2%
- b.
Bupivacaine: 5 mL of 0.5%
- a.
- 5.
Sterile gloves
- 6.
4 × 4 in. gauze
Basic Technique
- 1.
Patient positioning:
- a.
The extremity should be positioned on a hard surface.
- b.
If a distal radius fracture hematoma is being injected, then a hematoma block can be performed before or after setting traction.
- a.
- 2.
Landmarks:
- a.
Fracture site on radiograph
- b.
Area of swelling and/or deformity
- a.
- 3.
Steps:
- a.
Prepare the anesthetic.
- b.
Palpate the landmarks.
- c.
Prepare the skin with an antiseptic solution.
- d.
Numb the skin with ethyl chloride.
- e.
Inject the anesthetic.
- f.
Place a sterile bandage over the injection site (if desired).
- a.
Detailed Technique
- 1.
Prepare the anesthetic by drawing up 5 mL of lidocaine and 5 mL of bupivacaine (or an age-appropriate lower dose).
- 2.
Palpate the landmarks ( Fig. 2.1 ):
- a.
Use the radiograph to predetermine a soft tissue landmark that can be used as a guide for precise fracture location.
- b.
The deformity or a step-off may be palpable.
- a.
