The center of the palmer digital crease on the volar surface is identified as the injection site.
The hand is cleaned appropriately with betadine or chlorhexidine and a 25 gauge needle is inserted at the palmar digital crease penetrating through the flexor tendons to the bone.
The needle is then withdrawn slowly while applying gentle pressure to the plunger of the syringe. Once the needle is in the tendon sheath space, the lidocaine flows easily.
They recommend injecting 2-3 ml of lidocaine. It is also important to wait for the anesthetic to take full effect. I recommend waiting at least 7 to 10 minutes after the injection, then reassessing for satisfactory anesthesia.
Hematoma blocks can be extremely effective as primary analgesia or an adjunct for patients who cannot tolerate aggressive sedation.
Performing a hematoma block is pretty straightforward:
Feel with your thumb where the fracture is. It’s typically an easily identified step-off.
Next stick a needle in right at the fracture or just proximal to it. It’s easy because you just stick the needle in until it hits bone.
Once you do, start marching the needle toward where you think the fracture line is until you feel your needle drop into the space, usually with a tactile crunch.
I usually angle my needle to what I think is a similar angle of the fracture line as I march it forward looking for the fracture site. Often the angle needs to be adjusted a few times before you drop in.
Once in, draw back and you should see very dark blood in addition to what looks like olive oil in your syringe. The olive oil looking substance is fat. When you see this mixed with dark blood, you’re in the right place.
6. Inject. It should go easily. You’re done.
A few tips: Doing a hematoma block while hanging the arm in finger traps opens the fracture site and makes it a lot easier. One other thing, a little Ativan goes along ways to mellow patients out before and during the procedure.