Craig Spencer's Data Collection Project Fuels Innovation

Craig Spencer's Data Collection Project Fuels Innovation

EPI Journal

Rwandan fellowship project gives insight into the value for reliable data and the need for experienced local partners

In Memoriam: Gail Anderson

In Memoriam: Gail Anderson

1925 – 2014

Founding Father of Emergency Medicine

Market Forces

Market Forces

The Recruiter

Today’s EM job market: Know your target regions, tailor your goals and set yourself up for success

Doctors Say the Craziest Things

Doctors Say the Craziest Things

Financial Consult

Emergency physicians say some strange things when they're explaining their investment strategies. Here are four phrases to avoid

Go Big (Data) or Go Home

Go Big (Data) or Go Home

ED Benchmarking

Variations in practice make granular benchmarking comparisons troublesome. Fortunately, the EDBA’s big data has your back

Consider Tranexamic Acid for Traumatic Hemorrhage

Consider Tranexamic Acid for Traumatic Hemorrhage

Journal Club

Why the early use of TXA should be strongly considered for any patient requiring blood products for trauma-related hemorrhage

Greg Henry's ACEP Odyssey

Greg Henry's ACEP Odyssey

Welcome to the City of the Big Shoulders

The Unauthorized Guide to the ACEP Scientifc Assembly

Keeping an Eye on 72-Hour Bouncebacks

Keeping an Eye on 72-Hour Bouncebacks

Director's Corner

Dear Director, My CEO is concerned about our ED’s quality because we’ve experienced a recent increase in our 72-hour returns…

Flips, Falls and Other Orthopedic Adventures

Flips, Falls and Other Orthopedic Adventures

Practical Pediatrics

How to narrow down the diagnosis of pediatric leg pain when all categories of hip pain remain on the differential

Open Injuries to Flexor Compartment of Fingers and Hands

Open Injuries to Flexor Compartment of Fingers and Hands

Core Knowledge

Visualize, visualize, visualize. The decision to resort to surgery is multifaceted, based on location of injury, amount of damage and…

'Hey Doc, I Just Can't Pee'

'Hey Doc, I Just Can't Pee'

Ultrasound

You’ve got a seemingly straightforward complaint. Should you reach for your Foley or your ultrasound probe?

So EHRs Don’t Hurt Patient Sat or Throughput. Next?

So EHRs Don’t Hurt Patient Sat or Throughput. Next?

Measuring EHR Effectiveness

EHR usability needs to improve, but we need to focus on patient safety issues 

EHRs Are Inevitable, Yet Studies Still Pose Serious Questions

EHRs Are Inevitable, Yet Studies Still Pose Serious Questions

Measuring EHR Effectiveness

We’re seeing a dramatic increase in testing and a shocking amount of physician time being spent on electronic medical records

DEA Shifts Hydrocodone to Schedule II

DEA Shifts Hydrocodone to Schedule II

Fed’s Clamp Down on Hydrocodone

A good pill is hard to find - The reclassification of hydrocodone may make some EPs reluctant to prescribe it

When Ebola Shows Up At Your ED

When Ebola Shows Up At Your ED

Facts and Risk Levels

"Hey Dr T! We’ve got an Ebola suspect in room 64 for you. Don’t worry, we’ll walk you through this."

Frontpage Slideshow | Copyright © 2006-2014 JoomlaWorks Ltd.
Print
E-mail
Reprint
It is the first shift of your senior year and your attending asks if you can assist the 3rd year medical student with a “knee tap.”  Of course, you reply with confidence and a hint of arrogance.  You then find the medical student, who is frantically looking up the procedure on his Palm Pilot, and assure him that no pimping will occur today.  Both of you sit down and you began to educate a future physician on the art of the arthocentesis. 
   
The purpose of performing arthrocentesis of the knee or any other joint is twofold: therapeutic procedure to drain large effusions, hemarthroses and/or instill steroids or anesthetics;  and to diagnose crystal arthropathies or septic arthritis.  Arthrocentesis is contraindicated in patients with cellulitis overlying the site of needle entry.  Suspected bacteremia is a relative contraindication.  The largest synovial cavity in the body resides within the knee joint.  The knee may be tapped 1cm medial or lateral to the superior third of the patella and is directed toward the intracondylar notch.
 
Prior to performing the procedure, explain the procedure to the patient including risks, benefits and obtain informed consent.  Obtain your equipment and position the patient supine with the knee extended or flexed 15-20 degrees.  Identify the landmarks and mark the entry site with a skin marking pen.  When performing an arthrocentesis, maintain sterile conditions as joint fluid is prone to infection if bacteria is introduced.  Cleanse the skin with povidone-iodine or chlorhexidine and use a sterile drape.  Anesthetize the entry site using a 25-gauge needle, placing a wheal of lidocaine and then anesthetize the deeper tissues.  It is important to intermittenly pull back on the plunger during this step to exclude intravascular placement.  Obtain a large syringe with an 18-gauge needle and direct the needle behind the patella.  Do not “walk” the needle along the inferior surface of the patella as this may damage the delicate articulate cartilage.  Remove as much fluid as possible. “Milking” the effusion by applying gentle compression to the suprapatellar region with the opposite hand may aid in removal.  Once the procedure is complete, remove the needle and apply a bandage.  Crystal analysis can occur with one drop of synovial fluid, while cell counts generally require about 1 mL o ffluid.
   
The collected synovial fluid is then sent for cell count and differential, gram staining, culture, and crystal analysis.  A cutoff of 2000 white blood cells per milliliter and 75 percent polymorphonuclear cells is used to differentiate between non-inflammatory (OA and trauma) and inflammatory conditions.  Cell count and differential count cannot reliably differentiate among inflammatory conditions.  Gram staining and culture provide the most definitive evidence of septic arthritis.  The sensitivity is much higher for nongonococcal infections (50-75% gram stain and 75-95% culture) than disseminated gonococcal disease (<10% and 10-50% , respectively).  Consider blood, urethral, rectal or oropharyngeal cultures if gonococcus is suspected.  The sensitivity of crystal analysis is 80-95% for gout and 65-80% for pseudogout.  Needle-shaped, negative-birefringent, monosodium urate crystals seen in gout and rhomboid-shaped, positive-birefringent, calcium pyrophosphate crystals seen in pseudogout are visualized under a polarizing light microscope.  The presence of crystals does not exclude septic arthritis, although a St. Luke’s-Roosevelt Hospital retrospective review of crystal-positive synovial fluid aspirates suggests concomitant septic arthritis is rare (1.5% prevalence).  
    
Potential complications include a “dry tap”, failure to aspirate synovial fluid.  Obesity, hypertrophy of the synovium, obstruction of the needle lumen or misdiagnosis of the knee effusion may result in a dry tap.  A different approach (lateral or medial) should be attempted.  Localized trauma, pain, reaccumulation of the effusion or iatrogenic infection are other potential complications.  Arthrocentesis of the knee is a relatively benign procedure if properly performed.          

To get the full article please go to http://pmid.us/16687707
 
 
 

Add comment

Security code
Refresh

Popular Authors

  • Greg Henry
  • Rick Bukata
  • Mark Plaster
  • Kevin Klauer
  • Jesse Pines
  • David Newman
  • Rich Levitan
  • Ghazala Sharieff
  • Nicholas Genes
  • Jeannette Wolfe
  • William Sullivan
  • Michael Silverman

Subscribe to EPM