Search
Joint Fluid Analysis:
This is hte session in Baltimore for crab eating and beer drinking so we begin to see an increase in Gout pain. For those that are presenting with their first episode and you are concerned that they might have a septic joint, I am including this pearl to help analysis the fluid you will obtain from arthrocentesis.
| Diagnosis | Appearance | WBC | PMNs | Glucose % of Blood Level | Crystals | |
| Normal | Clear | <200 | <25 | 95 - 100 | None | |
| Degenerative Joint Disease | Clear | <4000 | <25 | 95 - 100 | None | |
| Traumatic Arthritis | Straw colored | <4000 | <25 | 95 - 100 | None | |
| Acute Gout | Turbid | 2000 - 50,000 | >75 | 80 - 100 | Negative birefringence | |
| PseudoGout | Turbid | 2000 - 50,000 | >75 | 80 - 100 | Positive birefringence | |
| Septic Arthritis | Purulent / turbid | 5000 - > 50,000 | >75 | < 50 | None | |
| Rheumatoid Arthritis | Turbid | 2000 - 50,000 | 50-75 | ~75 | None |
To view a gout crystal click this link.
To view a pseudogout crystal. Click this link
Pearls:
- A WBC Count >50,000 is septic arthritis until cultures are negative.
- Due to the wide range of WBC for septic arthritis have a high index of suspicion and do not discount the diagnosis because the WBC count is only 10,000.
References
Benjamin GC. Arthrocentesis. In: Roberts JR, Hedges JR, eds. Clinical procedures in emergency medicine. 3rd ed. Philadelphia: Saunders; 1998:919-932.