Hematoma Nerve Block
Overview
A hematoma block involves the instillation of local anesthetic into a hematoma, or more accurately the fracture line, of a fractured bone. Hematoma blocks are simple to perform, essentially devoid of systemic complications and can be used in an office, operating room, or emergency department setting.
Indications
Hematoma blocks can be utilized for analgesia alone for fractures or pain control during reduction. Hematoma blocks are most classically used for forearm fractures (Colle’s fractures) but can be applied to any fracture-related hematoma that is visible on physical exam or ultrasound, so long as local anesthetic can be safely infiltrated into the area.
Contraindications
There are few true contraindications to this block. They include:
- Infection (cellulitis) at the site of injection
- Allergy to local anesthetic being used
- Patient refusal
Some relative contraindications to consider:
- Patient needs a neural exam of the affected area
- Anticoagulation use or bleeding disorder (pressure and tourniquet can be applied to the affected area if necessary)
- Patient with prior neural lesion or active injury
Anatomy
Hematoma blocks classically have utilized the visible or palpable anatomy to identify the area of local anesthetic injection. Hematomas form at or around an area of fracture and are caused by localized bleeding from osseous blood vessels injured or severed by the fracture itself. It is important to recognize that hematomas do tend to localize to the area of fracture but are often somewhat gravity dependent and therefore may accumulate slightly distal to the fracture line. This becomes important in targeting the fracture line for optimization of our local anesthetic delivery, which is discussed in detail below. When using ultrasound guidance (recommended), the local anesthetic is delivered at the level of the fracture line rather than into the hematoma itself.
Materials
Technique
Blocks should be performed with aseptic technique using a skin antiseptic, sterile field, and sterile equipment (i.e. ultrasound) if possible. Allow appropriate dry time for your antiseptic. Block needles should be aspirated prior to every injection to avoid intravascular administration, and injection should be immediately stopped if the patient suddenly complains of pain or high pressure. As noted, landmark based hematoma blocks are a viable option, but US guided anesthetic delivery right to the fracture line is preferred. Both techniques are discussed below.
Landmark
- Place the patient’s extremity in a position to allow access to the hematoma.
- After applying antiseptic, the needle is inserted directly into the hematoma. The needle should be inserted at a 45-degree angle along the proximal aspect of the hematoma. Aspirate for blood to confirm entry into the hematoma, though a well clotted hematoma may not generate significant blood return.
- Inject 3-5 mL of local anesthetic.
Figure 3: Ultrasound image of a distal radius fracture. See animation for anatomical labeling. Click the animation for a full size version in a new tab.
Ultrasound
- Place the patient in a comfortable position that allows for easy application of the ultrasound probe and visualization of the fracture (Figure 5).
- Place the linear probe longitudinally across the extremity or area of fracture, parallel to the trajectory of the bone. Scan from proximal to distal and back distal to proximal to recognize the fracture line. The fracture line will appear as a loss of continuity or “jump” of the hyperechoic bone. Then scan from left to right over the fragment.
- After cleaning the area and placing a skin wheal, advance your needle in the longitudinal plane to the US probe. Gently advance the needle in this longitudinal plane; this allows for continued visualization of the entire needle. Advance the needle until the tip is as close to the fracture line as possible.
- Before injecting, aspirate to verify the needle is not intravascular and slowly inject the local anesthetic. Inject 3-5 mL of local anesthetic around the median nerve.
Figure 4: Ultrasound video showing a sweep through the fracture fragments of a distal radius fracture. Click the animation for a full size version in a new tab.
Figure 5: Image of patient and probe positioning for a hematoma block of a Colle’s fracture. Image shows none sterile sweep through the facture region. Click the image for a full size version in a new tab.
Figure 6: Still image of needle advancement to the fracture line. See animation for labeling. Click the animation for a full size version in a new tab.
Figure 7: Ultrasound video showing the slow instillation of local anesthetic. Click the animation for a full size version in a new tab.
Summary & Bullet Points
Hematoma Nerve Block
Overview
Indications
Hematoma blocks can be utilized for analgesia alone for fractures or pain control during reduction. Hematoma blocks are most classically used for forearm fractures (Colle’s fractures) but can be applied to any fracture-related hematoma that is visible on physical exam or ultrasound, so long as local anesthetic can be safely infiltrated into the area.
Contraindications
There are few true contraindications to this block. They include:
- Infection (cellulitis) at the site of injection
- Allergy to local anesthetic being used
- Patient refusal
Contraindications
Some relative contraindications to consider:
- Patient needs a neural exam of the affected area
- Anticoagulation use or bleeding disorder (pressure and tourniquet can be applied to the affected area if necessary)
- Patient with prior neural lesion or active injury
Anatomy
Materials
Technique
Landmark
Place the patient’s extremity in a position to allow access to the hematoma.
After applying antiseptic, the needle is inserted directly into the hematoma. The needle should be inserted at a 45-degree angle along the proximal aspect of the hematoma. Aspirate for blood to confirm entry into the hematoma, though a well clotted hematoma may not generate significant blood return.
Inject 3-5 mL of local anesthetic.
Ultrasound
Place the patient in a comfortable position that allows for easy application of the ultrasound probe and visualization of the fracture (Figure 5).
Place the linear probe longitudinally across the extremity or area of fracture, parallel to the trajectory of the bone. Scan from proximal to distal and back distal to proximal to recognize the fracture line. The fracture line will appear as a loss of continuity or "jump" of the hyperechoic bone. Then scan from left to right over the fragment.
After cleaning the area and placing a skin wheal, advance your needle in the longitudinal plane to the US probe. Gently advance the needle in this longitudinal plane; this allows for continued visualization of the entire needle. Advance the needle until the tip is as close to the fracture line as possible.
Before injecting, aspirate to verify the needle is not intravascular and slowly inject the local anesthetic. Inject 3-5 mL of local anesthetic around the median nerve.
References
- Hematoma (fracture) block is safe and effective way to provide analgesia to a patient with a fracture.
- Very few contraindications exist for this block (overlying infection, medication allergy).
- Hematoma blocks can be utilized in any patient with a fracture requiring anesthesia or analgesia (ie before reduction), so long as local anesthetic can be safely infiltrated into the area. It is commonly utilized for forearm (Colle’s) fractures.
- When injecting local anesthetic for a fracture, ultrasound can help localize the fracture line and the block is most successful with the fracture line, rather than the hematoma, is targeted.