Septic arthritis: Difference between revisions

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==Work-Up==
==Work-Up==
#Arthrocentesis with synovial fluid analysis
*Arthrocentesis with synovial fluid analysis
#*Synovial fluid culture only (not 100% sensitive)
**Synovial fluid culture only (not 100% sensitive)
#CBC  
*CBC  
#ESR
*ESR
#*Sn 94% (with 15mm/h cut-off)<ref>Hariharan, H, et al. Sensitivity of Erythrocyte Sedimentation Rate and C-reactive Protein for the Exclusion of Septic Arthritis in Emergency Department Patients. J of Emerg Med. 2010; 40(4):428–431. http://dx.doi.org/10.1016/j.jemermed.2010.05.029</ref>
**Sn 94% (with 15mm/h cut-off)<ref>Hariharan, H, et al. Sensitivity of Erythrocyte Sedimentation Rate and C-reactive Protein for the Exclusion of Septic Arthritis in Emergency Department Patients. J of Emerg Med. 2010; 40(4):428–431. http://dx.doi.org/10.1016/j.jemermed.2010.05.029</ref>
#CRP
*CRP
#*Sn 92% (with 20mg/L cut-off)
***Sn 92% (with 20mg/L cut-off)
#Blood Culture
*Blood Culture
#Gonorrhea culture (urethral/cervical/pharyngeal/rectal)  
*Gonorrhea culture (urethral/cervical/pharyngeal/rectal)  
#Imaging
*Imaging
#*Helpful for excluding other diagnoses (e.g. trauma, osteo)
**Helpful for excluding other diagnoses (e.g. trauma, osteo)
#Immunocompromised
*Immunocompromised
#*Consider mycobacterial or fungal arthritis
**Consider mycobacterial or fungal arthritis
**Leukemia history: predisposed to Aeromonas infections


==Management==
==Management==

Revision as of 22:25, 22 April 2015

Background

  • Most important diagnostic consideration in acute joint pain (can destroy joint in days)
  • Knee most commonly involved in adults; hip most common in peds
  • Most often seen in pts >65yr
  • Most common causative organisms
    • <35 y/o N. gonorrhoeae
    • >35 y/o S. aureus

Clinical Presentation

  • Fever
  • Warm, red, painful, swollen joint
  • Decreased range of motion to active and passive movement
  • Gonococcal arthritis
    • Urethritis/vaginitis may be absent
    • May have prodromal phase:
      • Migratory arthritis and tenosynovitis predominate before pain and swelling occurs
      • Macularpapular rash or pustules esp on hands/feet may proceed overt arthritis
  • Endocarditis should be considered in the presence of 2 or more affected joints

Differential Diagnosis

  1. Toxic synovitis
  2. Abscess
  3. Cellulitis
  4. Primary rheumatologic disorder (i.e. vasculitis)
  5. Iatrogenic
  6. Reactive arthritis (post-infectious)


Diagnosis

Arthrocentesis of synoval fluid

Synovium Normal Noninflammatory Inflammatory Septic
Clarity Transparent Transparent Cloudy Cloudy
Color Clear Yellow Yellow Yellow
WBC <200 <200-2000 200-50,000

>1,100 (prosthetic joint)

>25,000; LR=2.9

>50,000; LR=7.7

>100,000; LR=28

PMN <25% <25% >50%

>64% (prosthetic joint)

>90%

Culture Neg Neg Neg >50% positive
Lactate <5.6 mmol/L <5.6 mmol/L <5.6 mmol/L >5.6 mmol/L
LDH <250 <250 <250 >250
Crystals None None Multiple or none None
  • Viscosity of synovial fluid may actually be decreased in inflammatory or infectious etiologies, as hyaluronic acid concentrations decrease
  • The presence of crystals does not rule out septic arthritis; however, the diagnosis is highly unlikely with synovial WBC < 50,000[1]

Work-Up

  • Arthrocentesis with synovial fluid analysis
    • Synovial fluid culture only (not 100% sensitive)
  • CBC
  • ESR
    • Sn 94% (with 15mm/h cut-off)[2]
  • CRP
      • Sn 92% (with 20mg/L cut-off)
  • Blood Culture
  • Gonorrhea culture (urethral/cervical/pharyngeal/rectal)
  • Imaging
    • Helpful for excluding other diagnoses (e.g. trauma, osteo)
  • Immunocompromised
    • Consider mycobacterial or fungal arthritis
    • Leukemia history: predisposed to Aeromonas infections

Management

Arthrocentesis

  • Treatment based on diagnostic studies

Antibiotics

For adults treatment should be divided into Gonococcal and Non-Gonococcal

Gonococcal

Non-Gonococcal

Pediatrics

Sickle Cell

Coverage for Salmonella and Staphylococcus spp

  • Vancomycin 20mg/kg IV twice daily PLUS
    • Ciprofloxacin 400mg IV three times daily OR
    • Imipenem/cilastatin 1g IV three times daily

Consultation

  • Consult ortho for joint irrigation in OR if joint aspirate is indicative of infection

Disposition

  • Admit all to ortho

See Also

External Links

Source

  1. Shah K, Spear J, Nathanson LA, Mccauley J, Edlow JA. Does the presence of crystal arthritis rule out septic arthritis?. J Emerg Med. 2007;32(1):23-6.
  2. Hariharan, H, et al. Sensitivity of Erythrocyte Sedimentation Rate and C-reactive Protein for the Exclusion of Septic Arthritis in Emergency Department Patients. J of Emerg Med. 2010; 40(4):428–431. http://dx.doi.org/10.1016/j.jemermed.2010.05.029