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One of my favorite procedures to perform in the emergency department is subungual hematoma decompression. The procedure is quick, easy, nearly painless for the patient, and provides instant relief. Not to mention, using a cautery tool is just plain fun. And, this is a procedure that’s simple and lends itself to other non-hospital settings like primary care. While draining a subungual hematoma is simple, there are complications and considerations nurse practitioners must take into account with the procedure.

Here’s what nurse practitioners need to know about subungual hematoma decompression.

What is a subungual hematoma?

A subungual hematoma is a collection of blood under the nail. The collection typically results from trauma, often a crush injury, causing the vascular nail bed to bleed. Pooling blood under the nail results in increased pressure causing pain. Clinically, the finger appears swollen and tender with discoloration of the nail from the hematoma. Subungual hematomas may also be caused by repetitive minor trauma to the nail such as the toes of marathon runners.

Subungual hematoma assessment

Treatment of a subungual hematoma typically involves draining the associated blood collection to relieve pressure and pain. Before jumping in to the procedure, consider an X-ray of the affected digit to assess for an underlying fracture. Assess the edge of the nail closely. If nail edges are not intact, this may signal a more complex nail bed laceration. Nail bed lacerations require removal of the nail and laceration repair.Non-traumatic conditions like melanoma for example, may also cause darkening of the nail. Keep differential diagnoses in mind as you assess the discolored nail.

 Subungual hematoma drainage
There are a few clinically acceptable methods for subungual hematoma drainage. Ultimately, with each, pressure is released by placing a hole in the nail either with a large bore needle, or with a heated cautery instrument.

Before performing either method of release, prepare the area with iodine. Rest the patient’s hand on a solid surface in a comfortable position. If using a cautery tool, turn on the tool until the tip is hot. Tap quickly on the same spot at the base of the nail or in the center of the hematoma until the hole is through the nail. Applying too much pressure may result in a burn or pain. Blood should emerge from the opening. If blood does not emerge, you may need to make the hole slightly larger to accommodate blood flow or deeper to penetrate the nail. The patient should feel almost immediate relief once blood is expressed.

Releasing a subungual hematoma with an 18-gague needle is accomplished by spinning the needle with slight downward pressure on the nail, boring a hole until blood emerges.

With either method of drainage, gently squeezing the finger may facilitate further drainage from the site. Multiple holes may also be necessary for adequate drainage. The following video shows both methods of subungual hematoma release.


After Care

Once bleeding stops, apply antibacterial ointment and a bandage to the drainage site. If a fracture or significant soft tissue injury is present, a metal finger splint may be applied. Antibiotics are not routinely recommended. Patients should be instructed to keep the area dry for two days following the procedure. Patients should avoid soaking the finger for one week. Soaking the finger may break down the protective clot introducing bacteria into the opening. Advise the patient that the nail may eventually fall off. A new nail should grow unless there is extensive damage to the underlying nail matrix.


Cautery should not be performed on patients with acrylic nails as acrylic nails are flammable.

Performing subungual hematoma decompression is a simple procedure and provides significant relief to patients with crush and other digit injuries.


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One thought on “Subungual Hematoma Drainage Two Ways”

  • Antibiotics are however warranted if there is a fracture and you have drained the SH. By doing this, you have essentially created an open fracture and antibiotics should be prescribed. Important point to note.

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