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The Procedural Pause by James R. Roberts, MD,
& Martha Roberts, ACNP, PNP​

​Renowned emergency physician James R. Roberts, MD, and his daughter, Martha Roberts, ACNP, PNP, are the team behind The Procedural Pause.

The blog will focus on procedures that emergency physicians, residents, and midlevel providers are often called on to perform in the ED. Each case will cover the basics, the best approach for treatment, and pearls and pitfalls.

This blog conveys personal opinions and experiences, and application of the information here remains the professional responsibility of the clinician. Tthis blog is not intended to dictate standard of care, but is a clinical guide, not a legal document. Do not reference this site in court or as a defense. It is your responsibility to follow your hospital’s procedures and protocol and to practice under the guidelines of your professional license.

Please share your thoughts about the Roberts' posts.


Tuesday, March 3, 2020

The time it takes to perform a paracentesis is minimal, just about three minutes. Evacuating peritoneal fluid into vacuum-sealed containers will take extra time, but this can easily be monitored by a nurse while you send your samples to the lab and document your procedure. (See our previous blog, "Using Ultrasound for Paracentesis," discussing which laboratory samples to send:

The key to a successful paracentesis starts with identifying your landmarks, using ultrasound to determine your evacuation site, and having all your equipment prepped and ready to go. All paracentesis kits are different, and some do not include lidocaine, so you may need to obtain lidocaine before beginning the procedure. We also recommend having two sets of sterile gloves.


Photo by Martha Roberts.

The Approach

Ultrasound-guided paracentesis in the left lateral rectus site of the lower quadrant of the abdomen approximately 4-5 cm cephalad and medial to the anterior superior iliac spine.

The Pause

Have the patient empty his bladder before starting the procedure. The patient should be on cardiac and pulse oximetry monitors and positioned comfortably because he may feel dyspneic from the fluid overload. If a supine position is not possible, try a lateral decubitus position instead. A partner for this procedure is a must.

The Procedure

  • If the patient had a paracentesis recently, ask where the last site of entry was and use the same site. Evacuations can be completed daily if needed.
  • If this is the patient's first paracentesis, choose the lateral rectus left or right lower abdominal quadrant (area 2 in photo) or the infraumbilical region (area 1) in the midline through the linea alba. Confirm the absence of bowel at the puncture site with ultrasound.
  • Mark your entry site with a pen.
  • Look for and avoid entry over any engorged abdominal wall vessels.

PP-paracentesis-infraumbilical approach-linea alba-lateral rectus.jpg

The best sites for drainage include the infraumbilical approach in the midline through the linea alba. An alternate site is either side of the lateral rectus in either lower quadrant 4-5 cm cephalad and medial to the anterior superior iliac spine. Courtesy of Roberts and Hedges' Clinical Procedures in Emergency Medicine and Acute Care, 7th edition, Philadelphia: Saunders/Elsevier, 2018.

  • Clean the site with two chlorhexidine prep pads and apply a sterile drape.
  • Anesthetize the site, first by creating a superficial wheel and then go deeper using the Z-track method. (More about this below.)
  • The paracentesis catheter and needle come as a single unit that are separated once the needle tip is introduced into the peritoneal space. A blunt-tipped obturator within the needle retracts with pressure to expose a sharp tip. Once the peritoneal cavity is entered, the needle and obturator are removed to leave behind a plastic catheter, which drains the fluid.

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The needle apparatus separated, left, and a close-up of the tips. Once the needle is retracted, it cannot be reloaded because it is protected by a ball-spring mechanism. Photos by Martha Roberts.

  • Attach a syringe to the back of the paracentesis needle unit.
  • Insert the paracentesis unit into the anesthetized track perpendicular to the skin in a Z-track maneuver and slowly advance in 5 mm increments until fluid returns in the syringe (20-60 mL). Pull back on the syringe continuously to aspirate fluid. Then remove the needle to leave only the plastic catheter in the peritoneal cavity.
  • Set your filled syringe aside for diagnostic sampling and testing.
  • Ensure that the stopcock is closed and the roller ball is down on the tubing you plan to connect for further removal of fluid.
  • Securely attach the high-pressure tubing to the catheter hub.
  • Place the other end directly into a vacuum-sealed container.
  • Open the stopcock to allow fluid to pass, and release the roller ball on the tubing.
  • Once the procedure is completed, remove the catheter and place an adhesive bandage or pressure dressing to avoid fluid leakage. You can secure this with gauze pads, benzoin, and paper tape.
  • Yellow or clear fluid usually indicates cirrhosis, congestive heart failure, or nephrosis. Bloody fluid typically indicates neoplasm, although it could also be tuberculous peritonitis or pancreatic ascites.

Watch our video showing Peter Fishman, MD, performing a paracentesis on a 64-year-old man with end-stage liver cancer.

Discussion: The Z-track method minimizes fluid leakage from the puncture site. Injecting medication into the skin using this method is important to preventing post-procedure leaking. Once a needle has entered subcutaneous tissue and muscle, it opens a track that may not reseal immediately. There are also studies suggesting that Z tracks may reduce pain during injection. We suggest using the method during your paracentesis procedure.


Z tracks are used for all kinds of intramuscular injections and can be applied to other sites on the body. Pull and press the skin and tissue 2 cm caudad to the deep abdominal wall and insert the needle (A). Fluid returning in the syringe means you are in the peritoneum, and you can release traction (B). Z tracks help seal the track and prevent persistent fluid leaks (C, D). Courtesy of Roberts and Hedges' Clinical Procedures in Emergency Medicine and Acute Care, 7th edition, Philadelphia: Saunders/Elsevier, 2018.

Monday, February 3, 2020

​Paracentesis can be a quick and simple procedure with the right equipment and a well-rehearsed approach. It's important to practice this skill in the procedure lab and to familiarize yourself with the kit in your department a few times a year. This month, we focus on paracentesis set-up and basics, and next month we will review the nuts and bolts of completing the procedure.

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Important equipment for paracentesis: Five or six collection bottles, antiseptic prep, and a paracentesis kit. Consider longer needles for abdominal walls thicker than 2.5 cm.

Grab the ultrasound and a pen. Position your patient at a 45-degree angle, and begin scanning the abdomen. Find a colleague to help with this procedure because patients may become uncomfortable lying at that angle. You will also need help swapping out collection tubes and repositioning the patient. Rotate the patient slightly toward his side, and choose a left lateral approach for needle insertion. The procedure itself should be relatively painless once the anesthetic is administered.

Using the curved linear probe, drop your hand almost flush with the stretcher and scan for fluid.

Watch our video showing the basics of imaging and landmarks.

Ultrasound can help lower the rate of complications, avoid solid organ or intestine puncture, and help identify which patients are best suited for paracentesis. You can use medial or lateral approaches to identify pockets of fluid in the safe zone, avoiding the epigastric vessels and bladder, to determine your final approach.

It is best to hold the probe along the patient's left lower abdomen with the indicator pointing toward his head. Place the probe above the anterior superior iliac crest along the lateral gutters of the patient. You will be able to identify fluid and bowel quite quickly and easily.

PP-paracentesis-ultrasound image-ascites fluid-bowel-lateral approach.jpg

Ultrasound image of the abdominal wall, ascites fluid, and bowel using the lateral approach for paracentesis. Photo courtesy of Peter Fishman, MD.

Ultrasound Considerations

  • Measure the abdominal wall using ultrasound. You will need a longer needle if it is thicker than 2.5 cm.
  • Ensure that a safety zone of fluid more than 2 cm is visible on your screen.
  • Static or real-time approaches using ultrasound can be used. The static method is effective and safe as long as the patient remains in the same position and you have marked your area prior to needle insertion.
  • Have the patient empty his bladder if it appears full on ultrasound before needle insertion.

PP-lateral abdomen approach-ultrasound for paracentesis.jpg

Lateral abdominal position: Identifying important structures and safe zones for paracentesis. Photo courtesy of Phillips Perera, MD.

Basic Paracentesis Concepts

You are ready to begin once you have identified your site and set up your kit and collection bottles. Be prepared to fill at least two or three bottles. Once you change the bottles, you are no longer sterile, so consider having a colleague help.

What is the appropriate pre-paracentesis imaging or testing?

  • Perform ultrasound, clinical exam, and fluid wave testing.
  • Consider chest radiograph if you are concerned for pleural effusion.
  • Take into consideration prior paracenteses and the patient's diagnosis.

Where is the best place to insert the needle?

  • The left lateral approach as pictured above is the most commonly used point of entry because it avoids air-filled bowel that floats in the ascitic fluid and the cecum is relatively fixed on the right side.
  • Do not insert the needle into a surgical scar.

How much fluid should you remove and how quickly?

  • It is commonly suggested that 1.5-3 L of fluid should be removed in a single procedure to be of diagnostic value while the removal of 5 L of fluid or more is considered large-volume paracentesis. If a patient's diuretic responsiveness is unknown, removing 5 L is enough to reduce intra-abdominal pressure.
  • Eight to 10 L of fluid removal is not uncommon in severe disease or repeat patients.
  • Patients with severe hypoproteinemia may lose additional albumin into re-accumulations of ascites fluid and develop severe and acute hypotension and heart failure.
  • If you plan to remove larger amounts of fluid, consider intravenous fluid and vascular volume support.
  • The need for albumin replacement to prevent hypovolemia after large-volume drainage is controversial. (Hepatology. 2012;55[4]:1172;
  • Administering albumin solution (10 g/L of fluid removed) has been shown to reduce hemodynamic deterioration in patients with tense ascites. (Gastroenterology. 1988;94[6]:1493;
  • Slightly reposition the patient if flow slows down before removing the catheter.

Paracentesis in patients with a coagulopathy

  • An elevated INR and thrombocytopenia are not contraindications to paracentesis.
  • There is no need to administer FFP or platelets prior to the procedure, and a transfusion of blood products to reverse coagulopathy is not supported by available data. (Chest. 2016;150[1]:237;
  • The actual risk of bleeding following paracentesis is low except in patients with DIC.

No bleeding complications were found in a large study of 1100 patients undergoing high-volume paracentesis despite INRs as high as 8.7 and platelet counts as low as 19,000/mL. (Hepatology. 2004;40[2]:484;

What types of tests should you order?

Transudate fluidCaused by CHF, nephrotic syndrome, or hepatic cirrhosis
Exudate fluidCaused by inflammation or injury of the peritoneum, i.e., cancers, lymphoma, pancreatitis, autoimmune issues, TB
Color and consistency

Clear, straw, yellow: normal


Milky, thick: tumor, parasite, bacterial infection, perforated bowel


Bloody: benign or malignant tumor, hemorrhagic pancreatitis, perforated ulcer. Grossly bloody fluid in the abdomen (>100,000 red blood cells/mm3) indicates more severe trauma or perforation of an abdominal organ.


>30 g/L protein: exudate

<30 g/L protein: transudate

Gram stainLook for the overall presence of bacteria or fungi.
CultureThe presence of any microbes that have grown in a culture helps guide antimicrobial therapy.
GlucoseShould be equal to the glucose in the blood for transudate and <60 mg/dL for exudate (lower in cases of infection).
Blood cell count with differentialFew cells should be present, (lymphocytes usually). A polymorphonuclear cell count of >500 cells/mm3 is highly suggestive of bacterial peritonitis or exudative process.
Amylase levelElevation suggests pancreatic source.
Adenosine deaminaseRare test to look for tuberculosis in peritoneal fluid.
Fluid albumin level, SAAGThe serum ascites albumin gradient (SAAG) calculation (serum albumin level minus the fluid albumin level) may be used to differentiate between transudates and exudates. A SAAG level of 1.1 g/dL or greater suggests the presence of a transudate and less than 1.1 g/dL, an exudate.


Next month we will do a full paracentesis with step-by-step guidance and procedural tips.

Thursday, January 2, 2020

​Before you break out the bottles for a paracentesis, you may want to consider doing a test for ascites. Many procedures require executing an old-school test before even looking at a result or grabbing an ultrasound machine. Knowing what to look for on a physical exam may guide your practice and intervention dramatically. Using noninvasive tools first could help your patient avoid other tedious or unnecessary testing, which may also result in lost time. Incorporating ultrasound into your practice may also help you nail a diagnosis or allow you to perform a procedure better than you expected.

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A markedly distended abdomen due to ascites. The abdominal cavity may contain many liters of fluid.

Laying your hands on a patient's abdomen is still one of the best ways to help make an accurate diagnosis. This is true of such tests as deep pressure applied to the right lower quadrant to help rule out an appendicitis, which is about 91% sensitive (Shackelford's Surgery of the Alimentary Tract, Eighth Ed. Philadelphia: Elsevier; 2019), or deeply palpating the right upper quadrant to check for cholecystitis, which is about 97% sensitive. (J R Coll Surg Edinb. 1996;41[2]:88.) The fluid wave and fluid thrill tests have been used for years to check for ascites or free fluid in the abdomen. They are our tests of choice to perform before setting up for paracentesis, though a fluid wave is a more specific but less sensitive finding.

The Cause of Ascites

Ascites can be caused by many disease processes, and is found in patients with cirrhosis (80-85% of cases), liver and heart failure, cancers, kidney disease, pancreatitis, and even tuberculosis and hypothyroidism. (Semin Liver Dis. 1997;17[3]:191). Laboratory testing and imaging may provide more information, but your physical exam and assessment will target the problem. Adding point-of-care ultrasound to the mix will ensure that you are moving in the right direction.

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Ultrasound demonstrating fluid in the abdominal cavity is the gold standard to diagnose ascites.

How to Check for a Fluid Wave

Position your patient on his back at a 45-degree angle. This may be uncomfortable and cause increasing shortness of breath for many patients, and may be the first clue to the diagnosis. Then place your hands on the abdomen, one on the left lateral mid-abdomen and the other on the right. Use your left hand to tap gently on the left side of the abdomen, and your right hand will feel increased fluid forced up as it disperses through the abdomen. A positive test will cause the fluid to move quickly to the other side. The patient may report pain to the right-side as you complete the test. This can be done in reverse as well.

PP-fluid wave-video-distended abdomen-ascites-paracentesis.jpg

Watch our video of how to check for a fluid wave.

Signs of Ascites

  • Positive fluid wave
  • Dullness over flanks
  • Increased abdominal girth
  • Weight gain, scrotal or leg edema
  • Tympany over the abdomen
  • Shortness of breath or dyspnea in the supine position

Accuracy of the Fluid Wave Test

Clinicians may elicit several physical maneuvers to check for ascites. One study found the sensitivity of all physical exam maneuvers ranged from 50% to 94%, with the most sensitive test (90% accurate) being dullness over the flank region. (JAMA. 1982;247[8]:1164.) A study comparing physical exam with ultrasound findings found that the fluid wave sign had the highest specificity (100%) of all the physical maneuvers performed by physicians.

Ultrasound is the gold standard to ensure proper diagnosis of ascites. It is safe, quick, and easy to perform on any patient. Even pocket ultrasound devices can be used to obtain a quick image of fluid in the abdomen. (Intern Emerg Med. 2016;11[3]:461.)

Next month: POCUS for revealing ascites, marking your entry site, the pros and cons of Z tracks, and a paracentesis performed in the ED on a patient with ascites from liver cancer.

Thursday, December 5, 2019

​Fingertip injuries and amputations are common in the emergency department, often occurring on weekends when consultants are not available. Some experienced physicians may consider rongeuring distal tuft amputation injuries, but simple closure and expert consultation for more difficult cases are suggested.

PP-fingertip amputation.jpg

A fingertip amputation within zone III involving total amputation of the distal tip, fingernail, matrix, and tuft. Photos by M. Roberts.

Care of fingertip amputations in the ED should focus on removing debris and cleaning the wound as best as possible, closing the wound using available skin, bandaging and splinting for comfort, and considering the patient's risk for infection (antibiotics, tetanus update, etc.). It is also vital to control bleeding and provide pain relief. Follow-up with a specialist can usually be done in 24 to 72 hours, depending on the complexity of the wound. Full amputations with the part in hand should be referred immediately for possible reimplantation. Some of these injuries need a thorough washout in an OR or a revision of tendons and bones.

Management depends on the severity of the injury, degree of wound contamination, and available resources. (Injury. 2017;48[12]:2643.) Consider the patient's age, comorbidities, occupation, hand dominance, and mechanism of injury.

PP-fingertip amputation flap repair.jpg

Flap repair in the ED with applied bulky dressing. Photos by M. Roberts.

PP-fingertip amputation-fingertip anatomy.jpg

Anatomy of the fingertip. Photo: Lippincott Williams & Wilkins, 2018.

Fingertip amputations can be classified into three zones based on the extent of the injury to the bone. This knowledge is helpful when communicating with a hand or orthopedic specialist. Zone I injuries are distal to the bony phalanx and can be treated conservatively with frequent dressing changes over many weeks. Zone II injuries involve partial tuft or bone exposure, while Zone III injuries involve the loss of bone and nail. Zone I injuries are typically treated conservatively while Zone II and III injuries almost always need expert care. (Indian J Orthop. 2007;41[2]:163;

We do not recommend rongeuring the bone without experience or expert consultation. It is used in cases where the bone is exposed and skin is missing. Cutting the bone down using this tool will allow for a skin flap to cover the wound, which may not be possible otherwise. This technique may need to be mastered by physicians in rural settings or those who have limited access to specialty care.

Amputation Management

  • Young stable patient
  • Thumb
  • Dominant hand
  • Multiple digits injured
  • Sharp wounds, little damage
  • Upper extremity (children)


  • Associated life threats
  • Severe crush injuries
  • Inability to withstand surgery


  • Single digit, unless thumb
  • Avulsion injury
  • Prolonged warm ischemia >12 hours
  • Gross contamination
  • Prior injury or surgery to that part
  • Emotionally unstable patient
  • Lower extremity
  • Infection
  • Poor function

If the patient is a child and has multiple losses, salvage reimplantation is attempted and the relative contraindications are ignored. Courtesy of Roberts and Hedges' Clinical Procedures in Emergency Medicine and Acute Care, 7th edition, Philadelphia: Saunders/Elsevier, 2018.

Patients occasionally present with an amputated finger in a bag or on ice, and they can be eligible for replantation. Elevate the entire extremity and perform a digital nerve block. Wrap the distal portion of the injured finger in wet gauze. Do not place any of the loose parts directly in ice (frostbite), soak them in water (destroys remaining tissue), or scrub them with antiseptic. (Roberts & Hedges, 2018.) Control all bleeding with firm pressure, and use a tourniquet close to the amputated site if needed. Time is ischemia, so prompt referral, consultation, and transfer are imperative. Give IV antibiotics (i.e., Ancef, Unison), pain medication, and a tetanus shot while you are waiting for consultation or transfer. Multiple fingertip avulsions or amputations can be wrapped in wet saline gauze in a bulky but firm dressing.

If the amputation was caused by an animal and rabies is possible, you should administer the rabies vaccination and then rabies immunoglobin as you would for any other bite. Injecting the immunoglobulin around the bite site is necessary; the technique will vary by location. If you are unable to inject fully around the bite area, you can inject the rest of the immunoglobulin around the base or shaft of the affected finger.

A person exposed to rabies and never vaccinated should get four doses of the vaccine. The first is given on the day of presentation; the rest are given on the third, seventh, and 14th days. Find more information about doses and rabies vaccines, along with a free algorithm, from the CDC:

PP-amputated fingertip-video.jpg

Watch a video of an amputated fingertip.

Procedural Pearls

  • Complete digital block immediately upon presentation.
  • Image with plain film radiographs utilizing three views.
  • For more complex injuries in Zones II and III, immediately consult a specialist. You may consider handling Zone I injuries yourself with consultation and immediate flap repair. (See video below.)
  • Clean the wound thoroughly, but avoid scrubbing if the wound will be a candidate for reimplantation. Remove any foreign bodies.
  • Avoid tube gauze in general; it's difficult to put on and take off and doesn't have any real benefit when compared with just wrapping the finger with Kerlix. (See the video below for more on this technique.)
  • Don't spend a lot of time on cosmetics for these patients; they will get a revision. Preserve neurovascular status and know when to expedite care.
  • Clean the whole hand before wrapping it. No one wants to go home with a bloody mess.

PP-fingertip amputation-x-ray.jpg

Plain film radiographs for distal fingertip zone III amputation.

Jim weighs in: Expedite the preoperative workup of the patient and immediately notify the reimplantation team because these are crucial factors in the patient care.

Martha weighs in: If you are closing the wound using our flap method, use Prolene. It holds a looser tension and is easier to see (blue) and remove (slicker) than black nylon.

Friday, November 1, 2019

Subungual hematomas can be a terror. They are painful, ugly-looking, nefarious, and sometimes confusing. The ultimate goal is to drain the accumulated blood and relieve the painful pressure.

The best intervention is easy and straightforward: Leave the nail in place, and evacuate the blood under it. (Hand Surg. 2012;17[1]:151; Am J Emerg Med. 2006;24[7]:875; Emerg Med J. 2003;20[1]:65, Then, provide excellent discharge information without prescribing antibiotics.

PP-subungual hematoma-thumb.jpg

A subungual hematoma in a 21-year-old man who slammed his thumb in a car door about 12 hours before ED arrival. Photo by M. Roberts.

Distal extremities have millions of nerve endings, and preservation of the tissue and bone is crucial. Clinicians should test circulation and motor and sensation of the digit. Blood under a fingernail or toenail is usually caused by direct trauma such as crush injury or a stubbed toe to the distal phalanx.

The accumulation of blood causes the nail to discolor (to black, blue, or purple). The blood comes from a laceration to the nail bed or a tuft fracture. A significant collection of blood around the paronychium may be a clue that the patient has an avulsed nail and that removal of the nail may be indicated. It is important to treat all types of injuries within 48 hours of injury. (StatPearls Publishing. May 18, 2019;; Roberts and Hedges' Clinical Procedures in Emergency Medicine, 7th Edition. Philadelphia: Elsevier; 2018, p. 744-756.)

 PP-subungual hematoma-thumb-xray.jpg

AP, lateral, and oblique views showing a tiny distal tuft fracture of the left thumb in a 21-year-old man.

If a patient has a simple subungual hematoma that encompasses more than 50 percent of the nail bed, drain it with trephination. (Roberts and Hedges' Clinical Procedures in Emergency Medicine, 7th Edition. Philadelphia: Elsevier; 2018, p. 744-756.) This can be done by using a cautery pen or an 18-gauge needle. Gone are the days of heating a paper clip on a burner and hoping for the best. This can introduce bacteria into the nail bed and may not be effective because it does not retain heat. (Textbook of Pediatric Emergency Procedures, 2nd Edition. Philadelphia: Lippincott Williams & Wilkins; 2008; p. 939.)

The length of the germinal matrix is 7-8 mm. Its distal end forms a white crescent called the lunula. If a fingernail is avulsed from the matrix, it must be put back into place. It may be difficult to tell if the nail is avulsed. Nail growth can be disrupted and may lead to a deformity if there is significant scarring to the matrix. This can also result in permanent deformities and loss of the nail itself. (UpToDate. August 2019; The cuticle helps hold the nail in place, and disruption of this structure alone does not always mean nails will not grow back.

PP-subungual hematoma-anatomy-finger-nail bed.jpg

Anatomy of the finger and nail bed. Photo courtesy of Roberts and Hedges' Clinical Procedures in Emergency Medicine, 7th Edition. Philadelphia: Elsevier; 2018, p. 744-756.

The Approach

  • Consider radiographs of the affected extremity. (Emerg Med J. 2003;20[1]:65,; UpToDate. August 2019;
  • Many clinicians forgo x-ray because the presence or absence of a fracture does not influence treatment.

The Pause

  • A large-bore needle can be twisted into the nail to evacuate the nail bed, but heated trephination is the preferred and most useful and painless technique. (Am Fam Physician. 2005;71[5]:856;
  • Some patients may require a digital block depending on the extent of the injury. Many clinicians routinely perform a digital nerve block before trephination.

The Procedure

  • Clean the area with iodine, alcohol, or chlorhexidine.
  • Stabilize the digit.
  • Wear protective equipment (mask, face shield).
  • Consider a digital block. Some clinicians will not perform a digital block for straightforward subungual hematomas without significant tissue damage or separation from the nail matrix.
  • Puncture the nail using a hot trephination or cautery device, positioning the device at a 90-degree angle. (StatPearls Publishing. May 18, 2019;
  • Gently press the heated device into the middle of the nail. Using minimal pressure will avoid contact with the nail bed.
  • A pop will be heard when the nail is fully penetrated, and the subungual blood will drain immediately.
  • Be sure to make a hole that is at least 3-4 mm to promote continuous drainage. (UpToDate. August 2019;
  • Two or three holes may be required.
  • Be prepared for a high-pressure squirt from the nail as blood is evacuated.
  • Gently milk the nail to relieve any additional blood. Elevate the extremity.
  • Cover with a dry dressing, and consider splinting for comfort or a known fracture.
  • Antibiotics are not indicated for distal tuft fractures.

PP-subungual hematoma-thumb-trephination.jpg

Subungual hematoma with evacuation holes from hot wire trephination. The nail was not avulsed from the nail bed in this case. Photo by M. Roberts.

Remove the Nail?

There is no reason to remove the nail to repair an underlying laceration if the nail is intact and not avulsed from the nail bed. The intact nail will serve as a splint or protective cover. (Emerg Med J. 2003;20[1]:65; Removal should only occur when a nail base is avulsed and above the cuticle or if the laceration threatens the preservation of the nail or digit. This may be the case in a fingertip or toe avulsion. (UpToDate. August 2019;

Place the proximal nail back onto the nail bed after removing it and repairing the nail bed. Suture it in place in the middle of the nail on each side, including the nail and adjacent skin. (See our previous blog post on pediatric nail bed repair.)

Patients with simple subungual hematomas should not receive prophylactic antibiotics after trephination. This does not improve outcome. (UpToDate. August 2019, Splinting for three to four weeks may be beneficial for alleviating pain if the patient has a fracture. Subungual hematomas with a fracture are considered open fractures. Use a first-generation cephalosporin (cephalexin) if antibiotics are required. MRSA may be of concern in some patient populations, in which case clindamycin may be valuable although evidence is limited.

A meta-analysis of adult and pediatric patients found that cryoacrylates (Dermabond, Histoacryl) are as effective as suturing nail bed injuries if the nail is removed. (Pediatr Emerg Care. 2019;35[1]:75;

No specific follow-up is needed for straightforward trephinations. The nail will grow back in a few weeks, and the hole will disappear. If the nail was removed, the sutures should be removed in 10-14 days.


  • Point-of-care ultrasound can be used to identify nail bed laceration and underlying distal tuft fractures, aiding in repair. (StatPearls Publishing. May 18, 2019;
  • There is no significant difference in outcomes between the care of plastic surgeons and that of emergency physicians for uncomplicated pediatric nail bed laceration repairs. (Pediatr Emerg Care. 2011;27[5]:379;
  • Approximately 57 percent of subungual hematomas in children occur in those under age 5. (Pediatr Emerg Care. 2011;27[5]:379; Pain control and sedation techniques include:
    • Intranasal midazolam: Infants who are 1-5 months old: 0.2 mg/kg x1. (Pediatr Radiol. 1995;25[5]:341; Indian J Pediatr. 2006;73[11]:975.) Older than 6 months: 0.2.-0.3 mg/kg (max 10 mg) x1. (Emerg Med J. 2001;18[1]:39;; Arch Dis Child. 2011;96[2]:160; Pediatr Radiol. 1995;25[5]:341; Pediatr Emerg Care. 2008;24[5]:300;
    • Ketamine: Intranasal: Children at 3 months and older: 3-6 mg/kg (half dose per nostril). ACEP recommends ketamine only for those older than 3 months because of the risk of airway obstruction, laryngospasm, and apnea. (Ann Emerg Med. 2014;63[2]:247; Ann Emerg Med. 2011;57[5]:449; Intramuscular: 2-5 mg/kg as a single dose; may repeat after five to 10 minutes. Some have recommended smaller doses (2-2.5 mg/kg) for minor procedures.
  • Subungual hematomas can be drained up to 48 hours after the injury. (Roberts and Hedges' Clinical Procedures in Emergency Medicine, 7th Edition. Philadelphia: Elsevier; 2018, p. 744-756; UpToDate. August 2019;
  • Refer displaced fractures, intraarticular fractures, extensive nail bed injuries with avulsion or amputation, and infected wounds to a hand surgeon.
  • Do not confuse splinter hemorrhages with subungual hematomas. They can be seen with psoriasis, and are associated with infectious endocarditis.
  • Subungual epitheliomas or malignancies are best diagnosed by histologic exam.
  • Handheld cautery devices can reach about 2,250°F. The devices maintain a constant temperature, which are capable of killing all thermolabile bacteria and viruses (including HIV, hepatitis A and B). (J Am Podiatr Med Assoc. 1989;79[11]:566.)

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Watch a video showing the trephinationof a subungual hematoma.