March 11, 2011 by dailybolusoflr
A subungual hematoma is a collection of blood between the nail plate and the nail bed.
· The pressure in this potential space causes significant pain for the patient, which can be substantially relieved without medication or anesthesia.
· It is most commonly caused by a direct crush injury to the digit. It is important to determine if there is an underlying fracture to the bone, and although nail trephination effectively converts this to an open fracture, there is no literature to support that these patients had any adverse outcome.
· Nails will appear “bruised” with a blue-black discoloration.
· Typical patients in whom trephination should be considered are those with over 50% of the nail discolored or in patients with significant pain but with smaller surface coverage.
Acceptable methods currently include:
· Pre-heated paper clip
· Cautery device
· Pre-sterilized needle
· Commercial controlled nail trephination device (see reference at the end)
The process of trephination involves opening a hole in the nail to release the pressure of the built up hematoma. Hematomas up to 36 hours are still liquid and can be considered for drainage.
The following are important to consider.
· The nail should be properly cleaned with povidone iodine or chlorhexadine
· Pressure must be applied to the nail to ensure that the entire nail is penetrated. You will feel a ‘give’ when you are all the way through. You do not want to go any further to limit damage to the underlying nail bed
· The finger should not be soaked as this encourages bacterial overgrowth (patients should be bandaged and told to keep the finger dry for 2 days)
· Sometimes 2 or 3 holes must be made to ensure adequate drainage
· Artificial nails are flammable (yikes!)
Roberts and Hedges
American Journal of Emergency Medicine (2006) 24, 875–877
Linda Regan, MD FACEP
Program Director, Emergency Medicine Residency
Johns Hopkins Medical Institutions