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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, andadvanced practice 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 remains the professional responsibility of the clinician. This 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, June 2, 2020

​Emergency providers expeditiously sift and sort patients on their shifts and streamline procedures like how to place an ear wick in a patient with otitis externa, a quick and useful procedure for a patient who will reap the rewards.

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Standard ear wicks. The material is made from a dehydrated sponge composed of hydroxylated poly(vinyl acetate). It increases in size when liquid is applied. Photo by M. Roberts.

Otitis externa can cause significant swelling, irritation, pruritis, and pain to the ear canal. Occasionally, the canal is so swollen it may be difficult to administer ear drops. An ear wick can be inserted between the swollen canal walls to help instill medication and keep the medication around longer to assist with healing.

An ear wick is hard when you place it in the ear, and it softens and expands as soon as it is moistened. It can be used for several days, and an additional one can be inserted by the patient if it falls out. It should be noted that additional bacteria can penetrate ear wicks, but this can be prevented by continuous application of antibacterial ear drops. Ear wicks need priming with six drops of the antibiotic before starting an at-home regimen so the initial dose is fully absorbed. (J Laryngol Otol. 2017;131[9]:809.)

Causes of Otitis Externa

  • Bacteria, fungal, or viral infection
  • Water in the ear from swimming or poor drainage
  • Scratch or cut in the canal, digital trauma
  • Chemicals like shampoo, hairspray or gel, makeup or creams
  • Sweat and warm weather
  • Patients with eczema or psoriasis
  • Repeat trauma from foreign objects, like syringes to clear wax
  • Inner ear infection or otitis media

PP-expanded ear wick-otitis externa.jpg

Ear wick after expansion. Photo by M. Roberts

The Approach

Insertion of an ear wick for acute otitis externa.

The Pause

Consider prior episodes and treatments, and complete the best ear exam possible.

The Procedure

  • Ensure the canal is as dry as possible. Remove any foreign material.
  • Obtain two or three ear wicks.
  • Insert a single dry, condensed wick into the canal, gently pushing it through the inflamed walls. The wick should be inserted as far in as possible so it is not sticking out.
  • Once the wick is inserted, put ear drops directly over the wick to expand it.
  • Give the patient a few ear wicks to take home, and instructions how to use them.
  • Place ear drops to saturate the wick three to four times a day for five to seven days.
  • Most topical preparations should be administered three to four times daily. Topical fluoroquinolones can be given two times daily.
  • Ensure that the patient tilts her head to the opposite shoulder while instilling drops.
  • The wick allows the medication to stick around so having the patient lay on her side for three to five minutes isn't required.

The Drops

Topical therapy is an effective approach to treating otitis externa and has few side effects. The choice of drops typically depends on what is available and affordable or covered by the patient's insurance. This is worth noting because combination drops are often more expensive and harder to obtain. Interestingly enough, when prescribing dual antibiotic and glucocorticoid drops, writing for two separate concentrations is cheaper. A prescription for Ciprodex, the combined medication, is more expensive than one for ciprofloxacin ear drops and one for dexamethasone ear drops.

Instill three drops of each into the ear for each dosing. Remember that ophthalmic drops of the quinolone family, such as Cipro, can be used in the ear. The same goes for ophthalmic glucocorticoids. Often, pharmacists will call the department and suggest this substitution because it is more cost-effective. One systematic review found no significant difference in cure rates between antibiotic and antibiotic/glucocorticoid preparations nor between quinolone and nonquinolone antibiotics for otitis externa. (Otolaryngol Head Neck Surg. 2006;134[4 Suppl]:S24.) Another study revealed that adding steroids may be of benefit. (Adv Ther. 2007 May;24[3]:671.)

If you are considering bacterial coverage, consider all possible offending parties, which include but are not limited to Staphylococcus, Streptococcus, Pseudomonas aeruginosa, and Escherichia coli, with the most common pathogens being S. aureus and P. aeruginosa. Ofloxacin and ciprofloxacin will provide excellent coverage against these pathogens.

Neomycin-polymyxin B-hydrocortisone (Cortisporin Otic Suspension) can also treat otitis externa. Adding topical steroids to your treatment plan may help treat inflammation, edema, and pain. (Adv Ther. 2007 May;24[3]:671.) If pruritis is severe or the patient has had success with glucocorticoid drops in the past, consider adding dexamethasone to the treatment plan.

Additional antibiotic choices include tobramycin and gentamicin, which are also effective against S. aureus and P. aeruginosa, but one should be concerned about ototoxicity when using these products. These two medications are not routinely recommended, and should only be considered if a patient has a true allergy to cipro or neomycin. If a patient has a true allergy to oral fluoroquinolones, there is a possibility that topical treatment would cause an allergic reaction. It has been noted that allergic contact dermatitis has been notoriously associated with neomycin when used for prolonged courses. (Clin Otolaryngol Allied Sci. 1995;20[4]:326.)

Patients with ear pain should also be managed with oral NSAIDs; those with intense pain associated with severe disease may require opioid analgesics on rare occasions. Acetaminophen and NSAIDs combined may provide relief similar to opioid analgesic. (JAMA. 2017;318[17]:1661;; Evidence-Based Practice. 2020;23[2]:6;

Watch a video of this procedure.


  • Some patients have difficulty using ear wicks or the medications. Patients could have an allergy to the antibiotic drops used or issues with medication preservatives. This may cause the ear to itch more and worsen the situation.
  • Consider fungal infection if the patient has chronic otitis externa. Otomycosis can be a difficult fungal condition to treat and requires close ENT follow-up.
  • A common cause of failure for topical treatment is underdosing.
  • Periauricular cellulitis without evidence of deep tissue infection is generally treated with oral antibiotics.
  • Malignant (necrotizing) external otitis is a severe, potentially fatal complication of acute bacterial external otitis, often seen in diabetics. This infection can spread to the soft tissue, cartridge, and skull. These patients need oral and topical fluroquinolones and most likely admission to the hospital with emergent ENT consultation.

Jim Weighs In:

  • If you don't have an ear wick, you can instead fill the ear canal with cotton and put the drops on the cotton.
  • Tell the patient it might be helpful to have someone else put the drops in the canal because it can be difficult to do that without looking.
  • There have been reports of tendon inflammation and rupture with systemic fluoroquinolones. The literature on topical use is limited. Caution the patient about this.
  • Do not use alcohol or acetic acid to clean the ear until the tympanic membrane (TM) can be visualized. If there is a TM perforation, acidifying solutions can be particularly irritating to the mucosa of the middle ear.

Martha Weighs In:

  • Don't push the wick in so far that you can't see it, and always look for an underlying ruptured tympanic membrane.
  • The only safe drop to use on a ruptured TM is cipro or Ciprodex.
  • Otomycosis can be treated in the ED but can be time-consuming and is rarely an emergency. Chat with an ENT. The key is a clean and dry ear. Antifungal ear drops such as clotrimazole and fluconazole are needed to treat otomycosis. Acetic acid is another common treatment. Usually, a 2% solution of these ear drops is used several times a day for about a week.
  • We really love this Wiley Online reference that summarizes otitis externa and its causes and provides suggestions for treatments based on nefarious underlying diseases and disorders. It also talks at length about drops and how you may want to choose. (J Small Anim Pract. 2016;57[12]:668;
Ofloxacin (Floxin)

Directions: Instill five drops (0.25 mL) into the affected ear twice daily for seven days.

Solution: 0.3%, 5 mL bottle, $30.86-$34.30

Generic: 0.3%, 5 mL or 10 mL bottles, <$30

Ciprofloxacin (Cetraxal, Otiprio)

Directions: Instill four to five drops (0.25 mL) into the affected ear twice daily for seven days.


Solution 0.2%: Instill 0.25 mL (0.5 mg) solution (content of one single-dose container) into the affected ear twice daily for seven days.


Suspension 6%: Instill 0.2 mL (12 mg) suspension into the affected ear as a single dose.

Solution (Cetraxal Otic) 0.2% (each): $46.37.


Solution (Ciprofloxacin HCl Otic) 0.2% (each): $8.53.


Suspension (Otiprio Intratympanic) 6% (per mL): $339.84.

Ciprodex (combined cipro and glucocorticoid)

Directions: Instill four drops into affected ear(s) twice daily for seven days.


Suspension, ciprofloxacin 0.3% and dexamethasone 0.1% (7.5 mL).


Suspension (Ciprodex Otic) 0.3-0.1% (per mL): $39.85.

Neomycin-polymyxin B-hydrocortisone (Cortisporin Otic suspension, Cortisporin, Coly-Mycin, Pediotic)

Directions: Instill four drops three to four times daily for seven days; note that otic suspension is the preferred preparation.


Solution or suspension: Generic: neomycin 3.5 mg, polymyxin B 10,000 units and hydrocortisone 10 mg per 1 mL (10 mL).


Solution (Neomycin-Polymyxin-HC Otic)

1% (per mL): $10.07, 3.5-10000-1 (per mL): $10.49.


Suspension (Neomycin-Polymyxin-HC Otic) 3.5-10000-1 (per mL): $10.07-$10.49.

Dexamethasone + glucocorticoid

For otic use: 0.1% ophthalmic solution, topical: Initially, instill three to four drops into the aural canal two to three times a day; reduce dose gradually once a favorable response is obtained. Alternately, you may pack the aural canal with a gauze wick saturated with the solution; remove from the ear after 12 to 24 hours. Repeat as necessary.

Solution (dexamethasone sodium phosphate ophthalmic, which can be used as otic) 0.1% (per mL): $12.94.

Suspension (Dexycu Intraocular, which can be used as otic) 9% (per 0.5 mL): $714.00.


Suspension (Maxidex Ophthalmic, which can be used as otic) 0.1% (per mL): $18.10.


Source: External Otitis: Treatment. UpToDate, June 14, 2019; (subscription required).

Friday, May 1, 2020

​We discussed the initial approach to the red, hot swollen wrist joint last month, and this month we focus on arthrocentesis of the joint with a full video of the procedure, including ultrasound and joint aspiration.

PP-wrist aspiration-swollen wrist-erythema-septic arthritis.jpg

A swollen, painful wrist that is hot to the touch with scant erythema is concerning for septic arthritis. The patient had multiple Band-Aids on his fingertips from blood glucose testing for diabetes, which increased his chances of having a septic joint with the punctures serving as an entry site for infection. Photo by Martha Roberts.

The Procedure

Identify the swollen joint, review the differential diagnosis, and perform arthrocentesis using the static ultrasound-guided technique to complete joint aspiration.

The Pause

Three views of the wrist in a new presentation of a swollen joint with or without a straightforward history may be of significant value. Radiographs may show a foreign body, a fracture, or an effusion. Patients may not be the best historians, and they rely on us to rule out serious pathology. We suggest obtaining plain films on all swollen wrists at the time of initial presentation.

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Three-view x-ray images of the right hand of a 64-year-old man with diabetes showing soft tissue swelling. The final diagnosis was septic arthritis of the wrist. Photos by Martha Roberts.

The Procedure

  • Complete plain film radiographs, three views.
  • Consider PO medication before the patient goes to x-ray, such as acetaminophen or an anti-inflammatory. Plain films and equipment setup, along with consent, may take up to an hour or more to organize. Early identification of these patients in triage or the waiting area is crucial because you can obtain laboratory work (CBC, basic metabolic panel, C-reactive protein, sedimentation rate, blood cultures, etc.) in preparation for your procedure. This may help guide your final plan.
  • Place your patient in a supine position to complete this procedure.
  • Ensure the proper equipment is in place, and consider a partner to assist with countertraction of the wrist as you ultrasound the extremity.
  • Use a linear ultrasound probe and begin scanning the wrist.

PP-wrist aspiration-finger countertraction.jpg

Countertraction of the finger assists with obtaining images. Ask a partner to help during this procedure because there are many moving parts and the sterility of the procedure will be important during skin puncture. Photo by Martha Roberts.


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Landmarks of the left wrist. Photo courtesy of Roberts and Hedges' Clinical Procedures in Emergency Medicine and Acute Care, 7th edition, Philadelphia: Saunders/Elsevier, 2019.

 PP-wrist aspiration-ultrasound-radius-ulna.jpg

An ultrasound image of the radius and ulna and joint space.

  • Note the landmarks for the wrist joint. Confirm with ultrasound guidance and palpation of the wrist and hand bones (if tolerable for the patient).
  • Landmarks include the dorsal radial tubercle (Lister's tubercle), which is found at the dorsal and distal portion of the radius.
  • To find the extensor pollicis longus (EPL), have the patient flex and extend the wrist. It runs in a groove on the radial side of the tubercle.
  • Once you have identified the landmarks and marked your site, cleanse the area with Betadine or chlorhexidine.
  • Wear sterile gloves for this procedure, and put a sterile cover on the probe.
  • Hold the patient's wrist in a degree of flexion, approximately 20-30 degrees.
  • Insert 1% lidocaine, approximately 2-3 mL, into the joint space using a 27 g needle at the end of a 5 mL syringe. Aspirate and ensure you have not hit an arterial bloodline. Wait two to five minutes.
  • Insert a 22 g needle dorsally, just distal to the tubercle on the ulnar side of the EPL tendon. Avoid the snuffbox; it is more radial and distal, and will not allow you to enter the joint space. It is also too close to the radial artery and superficial nerve.

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Needle aspiration of the right wrist using ultrasound guidance and identification of the proper landmarks. Photo by Martha Roberts.

  • Aspirate as much free fluid as possible. Avoid multiple sticks.
  • Send laboratory testing to the lab. Consider the following tests on the fluid: cell count and culture, glucose, protein, serology (PCR), viscosity, chemistries, and crystals. Use a red-top tube or sterile container for fluid collection. Check with your lab before completing the procedure if you are unsure.
  • Apply a sterile dressing to the site.
  • Some patients may need a volar splint for overall pain, but the procedure itself should not be extremely painful.

The Cautions

  • Premedicate patients who are anxious and in pain.
  • Check and recheck the structures and landmarks before inserting a needle.
  • Maintain sterility.
  • Do not do this procedure with the patient sitting up or with legs dangling off the stretcher because a vagal response may occur. It's also more difficult to ultrasound and hold traction.
  • Patients on warfarin with therapeutic INRs may have an aspiration completed without reversal (check the INR before the procedure). (Mayo Clin Proc. 2017;92[8]:1223). Consider that patients with hemophilia need an injection of factor VIII post-aspiration.
  • Do not perform this procedure on patients with a prosthesis.

Watch a video of the complete procedure by James Carothers, DO, an emergency physician at Berkshire Medical Center in Pittsfield, MA.

Special thanks to Dr. Carothers and Walter Schlech, MD, the director of ultrasound at Berkshire Medical Center.

Wednesday, April 1, 2020

​The wrist is not commonly aspirated in the emergency department, but emergent arthrocentesis may be indicated for extreme or concerning cases, and tapping the wrist to determine the underlying pathology or relieve pain may be of great value. The synovial fluid from the joint space can be analyzed for crystals, infection, and blood. This information may help determine the overall plan and aid in decision-making and consultation. The ultimate treatment plan may include admission, intravenous antibiotics, multiple aspirations, and even surgical washout.

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A swollen, painful wrist that is hot to the touch is concerning for septic arthritis. Use ultrasound to confirm the proper aspiration site and the angle for the needle during arthrocentesis. This patient had multiple bandages on his fingertips from blood glucose testing, providing an entry for infection and increasing the chance of developing a septic joint.

Joint aspirations carry minimal risk when done properly. They may even have lower morbidity and mortality than those who undergo surgical debridement. (J Bone Joint Surg Am. 2015;97[7]:558; The wrist is complex, and our video highlights the anatomy using ultrasound (US). We suggest a static approach to determine if there is a collection of fluid or an abscess, and then consider US-guided needle aspiration of the joint.

Watch a video of Walter Schlech, MD, the ultrasound director at Berkshire Medical Center in Pittsfield, MA, using ultrasound to identify structures in the wrist.

A plain film radiograph should be done, especially if there is a history of trauma. A fracture or foreign body should be ruled out before aspiration is considered. Ask the patient about drug use or possible injection into the forearm, hand, or other joint space. Any history of IV drug use is relevant. It's also important to ask the patient if he has a known history of gout or pseudogout, prior septic joint, surgeries, recent tattoos, prosthetics, or recent steroid injections into the region.

 PP-ultrasound-high frequency linear probe-wrist aspiration.jpg

A high-frequency linear probe is used for wrist aspiration. Discover your landmarks using a static approach before donning sterile gloves and setting up. Photo by Martha Roberts.

Diagnostic reasoning for aspiration includes but is not limited to suspicion for septic arthritis, gout, hemarthrosis or effusion, inflammatory or noninflammatory arthritis, and complex (abscess) or simple cellulitis. Other indications include the potential for biopsy or therapeutic fluid drainage for pain relief. Rare underlying diagnoses include amyloidosis, fibromyalgia, and hyperparathyroidism. Consider acute on chronic renal failure or new renal failure. Examine all other joints and look at the pattern of the swelling, warmth, rash, and proximal joint spaces especially. Petechial rash or multiple joint involvement may suggest a more global issue.

Septic Joint Infections

Septic joint infection of the wrist is rare and nefarious. It should not be missed. Typical normal synovial fluid should be clear or straw-colored without any crystals, with a total white blood cell count under 200/mL. Osteoarthritis may have WBC counts in the 1000s, and rheumatoid or other inflammatory arthritis will have 20,000/mL or more WBCs.

Septic arthritis counts will typically be higher than 50,000 WBCs/mL. Regardless of these results, the literature has proven repeatedly that laboratory and synovial diagnostic testing may not provide complete certainty of diagnosis. (J Emerg Med. 2007;32[1]:23.) The erythrocyte sedimentation rate and C‐reactive protein may be useful over time, but they are not necessarily helpful in an acute presentation. (Acad Emerg Med. 2011;18[8]:781; The presence of crystals almost always means gout or pseudogout, but crystals do not always definitely rule out septic arthritis. Lab and synovial fluid testing are still recommended because it can help identify patients at risk. (Orthopedics. 2017;40[3]:e526.)

A growing body of literature has suggested that daily and repeated arthrocentesis and administering intravenous antibiotics are reasonable choices for septic joints. This approach has shown to be of greater value in some cases, with fewer complications than previously accepted and more aggressive approaches utilizing surgery and open washout. (Ann Plast Surg. 2017;78[6]:659.) Surgery does not come without risks, so a prudent clinician should consider admission, systemic antibiotics, and consultation when concerned for a septic joint. Patients with diabetes, WBC counts of higher than 85,000, and Staphylococcus aureus or MRSA infection are at higher risk for failure from a single aspiration and a single surgical debridement. (J Bone Joint Surg Am. 2015;97[7]:558; They may require longer stays in the hospital and intravenous antibiotics at home.

PP-wrist xray-soft tissue swelling-septic arthritis.jpg

X-rays showing soft tissue swelling in a 64-year-old man with diabetes. The final diagnosis was septic arthritis.

Microcrystals found in the synovial fluid include monosodium urate, calcium pyrophosphate dihydrate, calcium hydroxyapatite, and calcium oxalate. Gout produces uric acid crystals, but pseudogout will have no uric acid but be positive for calcium pyrophosphate.

Finding crystals in synovial fluid usually indicates gout or pseudogout but does not definitively discount other diagnoses. The presence of crystals cannot exclude septic arthritis with total certainty. A seven-year retrospective study examining 265 joint aspirations that contained crystals found 183 (69%) had gout crystals, 81 (30.6%) contained pseudogout crystals, and 0.4 percent had both. (J Emerg Med. 2007;32[1]:23.) Four (1.5%) of the aspirations had positive cultures for septic arthritis, but those also contained a mean WBC count of 113,000, significantly higher than the rest of the samples. Look at the WBC count (and full patient presentation) carefully if you suspect a septic joint, even if the sample contains crystals.

Injecting steroids into a septic joint is contraindicated. In fact, steroid injections in any joint (regardless of clinical setting) may not have any long-term benefit and may cause harm. Giving steroid injections in the ED is controversial, and can create conflict with consultants. One can always prescribe oral steroids to circumvent the need for intra-articular steroids. Future blogs will discuss steroid indications and technique.

Before and After Aspiration

  • Arthrocentesis uses a sterile technique. We will talk about this in Part II.
  • Avoid areas of superficial skin infection, moles, psoriasis, etc., during anesthetic injection or aspiration.
  • Aspirations can be done on patients taking warfarin with therapeutic INRs without reversal, but check the INR before the procedure. (Mayo Clin Proc. 2017;92[8]:1223.)
  • Inject patients with hemophilia with factor VIII after aspiration.
  • Aspiration of a joint with a prosthesis is considered high-risk and should be done by a consultant.
  • A water bath can be used instead of lubrication if the patient cannot tolerate the pressure of the US probe during the procedure.
  • When in doubt, admit.

PP-red erythematous rash-carpal bone-wrist-ultrasound-aspiration.jpg

This patient had a bright red, warm, erythematous rash over the carpal bones and a mole on the forearm. Use ultrasound to find the bundle of extensor tendons on the volar surface between the ulnar and radial bones, and plan aspiration at this site. Avoid superficial veins and arteries by identifying them first with ultrasound. Photo by Martha Roberts.

Special thanks to James Carothers, DO, an emergency physician at Berkshire Medical Center in Pittsfield, MA, and Walter Schlech, MD, the director of ultrasound there.

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.

PP-paracentesis-needle apparatus.jpg

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.